Urban Water Ecosystems in Africa and Asia: Challenges and Opportunities for Conservation and Restoration [1 ed.] 9781032565354, 9781032569543, 9781003437833

Table of contents :
Cover
Half Title
Series Information
Title Page
Copyright Page
Table of Contents
List of Figures
List of Tables
List of Contributors
Preface
Acknowledgements
1 From Urban Water Resource Management to Urban Water Ecosystem Management
1.1 Setting the Stage: Water and Urbanization in Asia and Africa
1.2 Urbanization in Asia and Africa
1.3 Challenges in Urban Water Ecosystems
1.4 Structure of the Book and the Main Contents
References
2 Integrated Resource Use Management Practices for Better Urban Water Management Through the Application of SES Lens
2.2 The Disconnect Between IWRM and Ecosystems: A Key to Failure
2.3 Indigenous/traditional and Local Knowledge-Based Ecosystem Management as a Possible Way to Connect IWRM to SES
2.4 Conclusion
References
3 Ecosystem Service Valuation and Risk Assessment of a Ramsar Site Region (India) for Strengthening Protection and Conservation
3.1 Introduction
3.2 Area of Study and Its Hydro-Geomorphic Signature
3.3 Dataset and Methodology
3.3.1 Data Sets & Land Use Land Cover (LULC) Classification
3.3.2 Computation of Ecosystem Service Values (ESVs)
3.3.3 Selection of Proper Exploratory Factors
3.3.4 Use of Machine Learning Models
3.3.4.1 Support Vector Machine (SVM)
3.3.4.2 Naïve Bayes (NB)
3.3.4.3 K-Nearest Neighbor (KNN)
3.3.5 Model Validation
3.4 Result
3.4.1 Land Use Land Cover Transformation Scenario
3.4.2 Analysis of the States of Ecosystem Service Valuation (ESVs)
3.4.3 Changing Pattern Analysis of ESVs in the Study Period (1975–2021)
3.4.4 Assessment of Wetland Conversion Risk Area
3.4.5 Model Validation
3.5 Discussion
3.6 Conclusion
References
4 Impact of Water Shortage and Climate Change On Peri-Urban Agriculture in Tunisia
4.1 Introduction
4.2 Materials and Methods
4.2.1 Study Area
4.2.2 Surface Water Monitoring
4.2.3 Water Deficit Evaluation
4.2.3.1 Model Description
4.2.3.2 Data Analysis and Processing
4.3 Results
4.4 Conclusion
References
5 Cultural and Scientific Understanding of Submarine Groundwater Discharge
5.1 Introduction
5.2 Water Discharge (WD)
5.3 Surface Water Discharge (SWD)
5.4 Groundwater Discharge (GWD)
5.4.1 Inland Groundwater Discharge (IGD)
5.4.2 Submarine Groundwater Discharge SGD
5.4.2.1 Submarine Fresh Groundwater Discharge (SFGD)
5.4.2.2 Recirculated Submarine Groundwater Discharge (RSGD)
5.4.2.3 Submarine Springs
5.4.3 SGD (Methods of Measurement and Measurement Units)
5.4.3.1 Methods of Measurement
5.4.4 Measurement Units
5.5 Importance and Threat of SGD
5.5.1 Nutrients Transported Through SGD
5.5.2 Contaminant Transport Through SGD
5.5.3 Sources
5.6 Spiritual, Religious, Cultural and Social Importance and Perspective
5.6.1 Myths and Facts About Submarine Springs
5.6.2 Cultural Heritage Is Derived From the Rituals of Work and Life in the Environments Near the SGD Sites
5.7 Services Provided By SGD
5.7.1 Revitalizing Agriculture
5.7.2 Promoting Fishing in the Areas Where It Is
5.7.3 Contributing to the Manufacture of Jewelry and Cosmetics
5.7.4 Availability of Drinking Water
5.7.5 Commerce
5.8 Importance of SGD
5.8.1 The Social Importance of SGD and Its Impact On Society Since Ancient Times
5.8.2 Volumetric and Chemical Significance of SGD
5.9 Conclusion
Acknowledgments
References
6 Migration Induced By Water Scarcity: A Brief Review
6.1 Introduction
6.2 Economic Meaning of Water Scarcity
6.3 Water Scarcity and Climate Change: Asian and African Context
6.3.1 Water Scarcity Trends and Climate Change Influence: Scenario of Asia and Africa
6.4 Methodology of the Study
6.5 Water Scarcity and Human Mobility in South Asia
6.5.1 Water Scarcity and Human Mobility in Africa
6.6 The Causal Linkages Between Water and Migration
6.7 Role of Water Policies, Sustainable Water Management Practices, and Migration Policies in Addressing the Challenge
6.8 Gaps Identified for the Future Research
6.9 Conclusion
Notes
References
7 Urban Water Sector Management, Challenges, Opportunities and Cross-Cutting Issues: A Case of Malawi’s Urban Water Sector
7.1 Introduction
7.2 Management of Urban Water Supply in Malawi
7.3 Urbanization and Urban Water Management in Malawi
7.4 Urban Water Challenges in Malawi
7.4.1 Accessibility
7.4.2 Urban Water Supply
7.5 Proposed Coping Strategies for Urban Water Stresses in Malawi
7.5.1 New Raw Water Sources
7.5.2 Rehabilitation of Aging Water Infrastructure
7.5.3 Reduction of Non-Revenue Water (NRW)
7.5.4 Financial Soundness and Water Tariff
7.5.5 Catchment Conservation
7.5.6 Integrated Water Resources Management
7.6 Water Management Accountability
7.7 Overarching Water Sector Governance in Malawi
7.8 Crosscutting Issues in Urban Water Resources
7.8.1 Gender
7.8.2 Research
7.8.3 Stakeholder Engagement
7.8.4 Capacity Building
Notes
References
8 Assessing Human Health Risks Associated to Water Stress: A Local Approach in the Indian Context
8.1 Introduction
8.2 Water Stress - Human Health - Spatial Planning Nexus
8.3 Study Area and Methods
8.3.1 Study Area
8.3.2 Risk Assessment Framework – the Indicator-Based Approach
8.4 Results
8.4.1 City’s Municipal Water Supply and Health Infrastructure
8.4.2 Ward Selection Using an Indicator-Based Approach
8.4.3 Water Stress and Human Health
8.4.4 Spatial Development Pattern and Disease Outbreak
8.5 Mitigation Strategies
8.5.1 Policy Level Strategies
8.5.2 Local-Level Strategies
8.6 Conclusion
Annex. A – Thresholds for Performing Inter-Ward Assessment
Annex. B – Characteristics of the Selected Wards
Annex. C – Household Survey Questionnaire
WATER CONSUMPTION PATTERN
HEALTH PROFILE AND INFRASTRUCTURE ACCESS
9 Water Ecosystem Management in Japan: Successes and Failures
9.1 Introduction
9.2 Methods
9.3 Case Studies
9.3.1 The Kuma River
9.3.2 The Yahagi River
9.4 Concluding Remark
References
10 Building Resilience to Climate Change Through Water Retention Solutions in Ca Mau City, Vietnam
10.1 Introduction
10.2 Research Approach and Method
10.2.1 Study Area
10.3 Study Approaches
10.4 Results and Discussion
10.4.1 Issues in Ca Mau Province
10.4.1.1 Natural Hazard in Ca Mau
10.4.1.2 Landslides Along the Sea Dike in the West of Ca Mau
10.4.1.3 Local Inundation in Ca Mau City
10.5 Proposing Solution for Ca Mau City
10.5.1 Maintaining Ecosystem Services for Ca Mau in the Context of Climate Change
10.6 Ca Mau City Requires the Construction of a Drainage System
10.7 Conclusion and Recommendations
References
11 Quantification of Ecosystem Benefits of Community Plantation and Its Impacts On Human Well-Being: A Case Study From Kenya
11.1 Introduction
11.2 Material and Methods
11.2.1 Study Site
11.2.2 Data Collection
11.3 Results and Discussions
11.4 Afforestation Type and Its Long-Term Effect
11.5 Conclusion
Acknowledgments
Appendix – 1 Full Questionnaire
12 The Production of Hydrosocial Space in Contemporary China
12.1 Introduction
12.2 A Water-Rich Region: the GBA
12.3 GBA Urbanization and Its Effects On Rivers
12.4 Pearl River Delta Water Management History and Core Policies
12.5 Innovative Policy and Practice: Shenzhen Water Strategy
12.6 A Shift in Hegemonic Values: Evidence From Policy and Gray Literature
12.7 Case Study: the Dasha River
12.8 The Dasha Rehabilitation Process
12.8.1 Phase I. Flood Safety (1996–2003)
12.8.2 Phase II. Water Pollution Management (2008–2016)
12.8.3 Phase III. Ecological Corridor Construction (2017–2019)
12.9 Discussion
12.9.1 The Coevolution of Society and Water
12.9.2 Changing Hegemonic Societal Values in Water Management and Landscape
12.10 Conclusion
Acknowledgments
References
13 Water Accessibility: Information Failures and Beyond
13.1 Introduction
13.2 Water Tank Adoption in Kenya
13.2.1 Background
13.2.2 Intervention
13.2.3 Asymmetric Information
13.2.4 Limitations
13.3 Related Interventions
13.3.1 Context Matters
13.3.2 More Than Just Information
13.3.3 Relevant Information and Incentives
13.3.4 From Information to Action
13.4 Conclusion
References
14 Flood Management Issues in Dhaka City: Identifying Challenges and Sustainable Solutions
14.1 Introduction
14.2 Background
14.3 Main Causes of Urban Flooding in Dhaka
14.4 Gaps of Flood Management Policies in Dhaka
14.5 Sustainable Approaches to Flood Risk Management in Dhaka City
14.6 Conclusion
References
15 Challenges and Opportunities for Urban Water Ecosystems in Asia and Africa: Conclusions and Way Forward
15.1 Major Challenges of Urban Water Ecosystem Management
15.1.1 States and Impacts
15.1.2 Development Challenges
15.1.3 Realistic Valuation for Sound Management of Urban Water Ecosystems
15.1.4 Effective Policies and Planning
15.1.5 Research and Policy-Related Gaps On Urban Water Ecosystems in Asia and Africa
References
Index

Citation preview

Urban Water Ecosystems in Africa and Asia

This book examines urban water ecosystem management and restoration through selected case studies in Asia and Africa. Employing a socioecological approach, this volume presents insights on the interlinkages between water, humans, and environmental conservation in an urban context. Topics include human health risks, population displacement and migration, water pollution, water scarcity, flood management, water infrastructure, afforestation, and the effects of climate change. Case studies are drawn from a variety of countries in Africa and Asia, including China, Japan, India, Vietnam, Bangladesh, Kenya, Malawi, and Tunisia, which demonstrate a wide range of different challenges, and opportunities. Overall, this book argues that to better manage urban water resources, there needs to be a shift from urban water management to urban water ecosystem management. This shift needs to acknowledge the complex bio-​ physical and socio-​political dimensions of water ecosystems. This book will be of great interest to students and scholars of water resource management, ecosystem services, urban studies, environmental conservation and sustainable development. Shamik Chakraborty (PhD) is an associate professor at the Graduate School of Advanced Sustainability Science, University of Toyama, Japan. Prior to this he worked as a Lecturer at the Sustainability Co-​creation Programme at Hosei University, Japan. He has also served as a JSPS-​UNU postdoctoral fellow at the United Nations University, Institute for the Advanced Study of Sustainability (UNU-​IAS), and as a visiting research fellow at the Integrated Research System for Sustainability Science (IR3S) (presently, Institute for Future Initiatives) at the University of Tokyo. As a human geographer, he is interested in studying human-​ environment interactions from a social-​ecological systems perspective. He has worked with the concepts of social-​ecological systems, local ecological knowledge, and ecosystem services in different ecosystems in Japan, India, Bangladesh, Nepal, Indonesia, and the Philippines.

Amit Chatterjee (PhD) has a combined experience of more than one and half decades in teaching, research and industry and is presently an Associate Professor in the Department of Geography at Visva-​ Bharati University, Santiniketan, India. His research interest includes urban sustainability, land and environment. Dr. Amit has completed successfully a number of collaborative research and consultancy projects, including those on Urban Co-​benefits (UNU-​IAS, Japan), Urban Missions in India-​targets, performance and linkages to UN-​SDGs (GIZ), Politics of Care in Pandemic Time (UCL’s Global Engagement Funds), Urban Biodiversity (UNU-​IAS, Japan), Shelter for All under Design Innovation Centre (Govt. of India). Pankaj Kumar (PhD) is working as a senior policy researcher in the field of water resources and climate change adaptation at the Institute for Global Environmental Strategies (IGES), Japan. Prior to this, he worked as JSPS/​UNU-​IAS postdoctoral fellow in United Nations University, Institute for Advanced Study of Sustainability (UNU-​IAS), Tokyo; for more than three years. His research work focused on socio-​hydrology, water security, hydrological simulation and scenario modelling, and water-​health-​food-​energy nexus, a transdisciplinary work aimed to give policy relevant solutions to enhance community resilience to global change and a sustainable development of water environment and human well-​being. In addition, he is actively engaged in capacity development on various numerical tools used for water resource management, intended for local government officials and relevant stakeholders in different Asian countries. He has work experience with different global assessments like IPCC, IPBES and GEO as Chapter scientist and lead authors respectively. He has several peer reviewed articles (>170) in high impact factor journals, one authored book, one edited book to his credit.

Earthscan Studies in Water Resource Management

New Perspectives on Transboundary Water Governance Interdisciplinary Approaches and Global Case Studies Edited by Luis Paulo Batista da Silva, Wagner Costa Ribeiro, and Isabela Battistello Espíndola The Role of Law in Transboundary River Basin Disputes Cooperation and Peaceful Settlement Chukwuebuka Edum Desalination and Water Security Chris Anastasi Flood Risk and Community Resilience An Interdisciplinary Approach Lindsey Jo McEwen Water Politics and the On-​Paper Hydropower Boom Power, Corruption, and Sustainability in Emerging Economies Özge Can Dogmus Water Justice and Groundwater Subsidies in India Equitable and Sustainable Access and Regulation Gayathri D. Naik Climate Change and Water Scarcity in the Middle East A Transitional Approach Marielle Snel, Nikolas Sorensen, and Reed Power Urban Water Ecosystems in Africa and Asia Challenges and Opportunities for Conservation and Restoration Edited by Shamik Chakraborty, Amit Chatterjee, and Pankaj Kumar For more information about this series, please visit: www.routle​dge.com/​Earths​can-​Stud​ies-​in-​Water-​ Resou​rce-​Man​agem​ent/​book-​ser​ies/​ECWRM

Urban Water Ecosystems in Africa and Asia Challenges and Opportunities for Conservation and Restoration

Edited by Shamik Chakraborty, Amit Chatterjee, and Pankaj Kumar

First published 2025 by Routledge 4 Park Square, Milton Park, Abingdon, Oxon OX14 4RN and by Routledge 605 Third Avenue, New York, NY 10158 Routledge is an imprint of the Taylor & Francis Group, an informa business © 2025 selection and editorial matter, Shamik Chakraborty, Amit Chatterjee and Pankaj Kumar; individual chapters, the contributors The right of Shamik Chakraborty, Amit Chatterjee and Pankaj Kumar to be identified as the authors of the editorial material, and of the authors for their individual chapters, has been asserted in accordance with sections 77 and 78 of the Copyright, Designs and Patents Act 1988. All rights reserved. No part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers. Trademark notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe. British Library Cataloguing-​in-​Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging-in-Publication Data Names: Chakraborty, Shamik, editor. | Chatterjee, Amit (College teacher) editor. | Kumar, Pankaj (Research manager), editor. Title: Urban water ecosystems in Africa and Asia : challenges and opportunities for conservation and restoration / edited by Shamik Chakraborty, Amit Chatterjee and Pankaj Kumar. Description: Abingdon, Oxon ; New York, NY : Routledge, 2025. | Series: Earthscan studies in water resource management | Includes bibliographical references and index. Identifiers: LCCN 2024034523 (print) | LCCN 2024034524 (ebook) | ISBN 9781032565354 (hardback) | ISBN 9781032569543 (paperback) | ISBN 9781003437833 (ebook) Subjects: LCSH: Municipal water supply–Africa–Management–Case studies. | Municipal water supply–Asia–Management–Case studies. | Water quality management–Africa–Case studies. | Water quality management–Asia–Case studies. | Water resources development–Africa–Case studies. | Water resources development–Asia–Case studies. Classification: LCC TD220.2 .U63 2025 (print) | LCC TD220.2 (ebook) | DDC 363.6/1–dc23/eng/20240816 LC record available at https://lccn.loc.gov/2024034523 LC ebook record available at https://lccn.loc.gov/2024034524 ISBN: 9781032565354 (hbk) ISBN: 9781032569543 (pbk) ISBN: 9781003437833 (ebk) DOI: 10.4324/​9781003437833 Typeset in Times New Roman by Newgen Publishing UK

Contents



List of figures List of tables List of contributors Preface Acknowledgements

1 From urban water resource management to urban water ecosystem management

x xiii xv xxvii xxix

1

S H A M I K C H A K R A B O RT Y, A M I T C H AT T E R J E E , A N D PA N K A J K U M A R

2 Integrated resource use management practices for better urban water management through the application of SES lens

11

S H A M I K C H A K R A B O RT Y, G O W H A R M E R A J , G E E T H A M O H A N , PA N K A J K U M A R , A M I T C H AT T E R J E E , A N D S H I B S A N K A R B A G D I

3 Ecosystem service valuation and risk assessment of a Ramsar site region (India) for strengthening protection and conservation

22

S O U M I K S A H A , B I S WA J I T B E R A , P R AVAT K U M A R S H I T, S U M A N A B H AT TA C H A R J E E , N A I R I TA S E N G U P TA , D E B A S H I S H S E N G U P TA , A N D PA RT H A P R AT I M A D H I K A RY

4 Impact of water shortage and climate change on peri-​urban agriculture in Tunisia

52

M O H A M E D K E F I A N D C H O K R I D R I D I

5 Cultural and scientific understanding of submarine groundwater discharge N A G H A M I S M A E E L A N D K O U S I K D A S

68

viii  Contents

6 Migration induced by water scarcity: a brief review

87

R I C H A A N D S U B I R S E N

7 Urban water sector management, challenges, opportunities and cross-​cutting issues: a case of Malawi’s urban water sector

105

WA LT E R C H I N A N G WA A N D L I N D A C H I N A N G WA

8 Assessing human health risks associated to water stress: a local approach in the Indian context

128

D R U T I G A N G WA R A N D R A M A U . PA N D E Y

9 Water ecosystem management in Japan: successes and failures

153

S H A M I K C H A K R A B O RT Y, G O W H A R M E R A J , PA N K A J K U M A R , A N D A M I T C H AT T E R J E E

10 Building resilience to climate change through water retention solutions in Ca Mau City, Vietnam

167

H U Y N H V U O N G T H U M I N H , L E A N H T U A N , N G U Y E N D I N H G I A N G N A M , T R A N VA N T Y, K I M L AVA N E , PA N K A J K U M A R , A N D N I G E L K . D O W N E S

11 Quantification of ecosystem benefits of community plantation and its impacts on human well-​being: a case study from Kenya

183

PA N K A J K U M A R , T O M O K I YA G A S A K I , G O W H A R M E R A J , S H A M I K C H A K R A B O RT Y, R A J A R S H I D A S G U P TA , A M I T C H AT T E R J E E , H U Y N H V U O N G T H U M I N H , B I N AYA K U M A R M I S H R A , R A M AV TA R , O S A M U S A I T O , A N D K A Z U H I K O TA K E U C H I

12 The production of hydrosocial space in contemporary China

200

G I A N N I TA L A M I N I A N D D I S H A O

13 Water accessibility: information failures and beyond H A R I S A N K A R K R I S H N A D A S A N D K R I S T I N A M AT Y S I K

220

Contents  ix

14 Flood management issues in Dhaka City: identifying challenges and sustainable solutions

229

S H A N TA N U K U M A R S A H A , M D . AYAT U L L A H K H A N , MD. ASIF BIN KABIR, AND MD. MUJIBUR RAHMAN

15 Challenges and opportunities for urban water ecosystems in Asia and Africa: conclusions and way forward

245

S H A M I K C H A K R A B O RT Y, A M I T C H AT T E R J E E , A N D PA N K A J K U M A R

Index

251

Figures

2.1  Location of the peri-​urban mangrove area near Mombasa, Kenya 3.1  Geographical location of the study area 3.2  LULC map of the referenced years (1975, 2000 and 2021) along with LULC change statistics for the consecutive years 3.3  Spatial ordination of ESVs (USD/​ha/​year) in 1975, 2000 and 2021 using a. C97a, b. D12, and c. C97b unit values 3.4  Different causative factors used to assess the wetland vulnerability within EKW region based on previous studies, opinions of the native people, a. Distance from lost wetlands, b. Distance from canal, c. Settlement density, d. Slope, e. LULC, f. Distance from road, g. Distance from developed areas and h. Cropland density 3.5  Wetland conversion susceptibility maps using different machine learning models, a. SVM, b. NB and c. KNN 3.6  Bar graph showing the spatial extension of susceptibility classes that are determined using SVM, NB and KNN models 3.7  ROC-​CURVE shows the prediction capability of the used models 4.1  Study area location 4.2  Total water requirement and irrigation requirement 4.3  Total water requirement and irrigation requirement under climate change 4.4  Variation of spatial extent of the reservoir 4.5  Relationship between reservoir filling and rainfall 4.6  Variation of Lebna reservoir 4.7  Monthly total irrigation deficit and monthly effective rain 4.8  Irrigation deficit by growth stage and by crop 4.9  Shadow price (Lagrange multiplier) as a function of irrigation deficit severity 4.10  Irrigation deficit under climate change scenario 5.1  Water discharge classification

17 25 29 32

33 42 43 45 54 57 58 59 59 61 62 63 64 65 69

List of figures  xi 5.2  Chandipur beach, Orrisa, India 16-​12-​2023 5.3  Lombok Submarine Spring in Indonesia 5.4  Submarine springs in intertidal zone, Gunung Kidul, Indonesia 5.5  Submarine springs Syria, Tartous, Alhesha 28-​05-​2023 6.1  Water scarcity projections across countries 6.2  Water and migration linkages 7.1  Map of distribution of water sources in Malawi 7.2  Urban population growth rate for Malawi 7.3  Trend in urban population in Malawi from the years 2013 to 2022 8.1  Research methodology 8.2  Geographical location and area of the study area (reproduced from LMC, 2015) 8.3  Land use landcover maps of Lucknow (reproduced from Thematic Maps services on ISRO’s Geo-​Portal) 8.4  Density distribution of registered healthcare establishments in the city 8.5  Multivariate map of parameters considered in study area selection: ward-​wise status of main source of drinking water, population growth, and healthcare infrastructure in Lucknow 8.6  Multivariate map showing water quality, disease outbreak, and water shortage patterns in Ward 15 9.1  Location of the Kuma River and Yahagi River basins 9.2  (a) Ichifusa Dam was established in 1959. (b) Setoishi Dam was established in 1958. (c) Arase Dam was established in 1954 and removed in 2018. (d) Yohai barrage that stops the annual sweetfish run (Arguably built in 1608). (Photograph by Shamik Chakraborty.) 9.3  (a) Woody debris-vital component for biodiverse rivers-​taken out from the river as they can enter and damage the Setoishi dam. (b) Bulldozers await their turn to carry the woody debris and dispose of it elsewhere. (c) Perennial grass cover and formation of a ‘char’ land in the midstream of the Kuma River. These ‘char’ lands are part of the underwater riffle sequence of the river where fish used to come for foraging, and thus these charlands denote the local degradation of the riverine ecosystem. (d) A local elementary school on a raised platform beside the Kuma River main flow to cope with the raised water levels due to release from the dam during periods of heavy rain. (Photographs by Shamik Chakraborty.) 9.4  (a) Concrete rip-​raps in the land-​water interface region of the Kawabe River, which, according to local experts, were vital spawning grounds for fish like freshwater eels as it degrades the lateral connectivity of the river. (b) A concrete weir on one of the tributaries of the Kawabe River retarding the natural flow of sediments, and like dams, it degrades the longitudinal connectivity of the river. (c) A section of the Kawabe River where the dam

72 73 73 74 97 98 106 109 109 131 132 133 137 139 140 155

158

159

xii  List of figures was planned, the large concrete bridge in the background denotes the expected water level, which would have submerged the small bridge below it. (d) A section of the upstream of the Kawabe River where the dam was planned. These roads marked the expected pond level of the dam 10.1 Location of Ca Mau province and meteorological station 10.2 Occurrence frequency of various drought events at SPI 3 (a), SPI 6 (b), and SPI 9 (c) over 14 meteorological stations in the VMD 10.3 Historical evolution of the shorelines in Ca Mau coastal area from 1896 to 1991 11.1 Map of study area showing Karura Forest Reserve 11.2 Integrated approach for data collection 11.3 Summary of a questionnaire survey to assess nature’s contribution to the people 11.4 Perception of local people about the benefits from this community-­ led plantation 11.5 Impact of afforestation on water resources 11.6 Relation between community plantation and water quality 11.7 Summary showing (a) contribution of the forest resources to people, (b) Diversity index for number of types of forest products usage for indigenous and exotic plant species 12.1 GBA urbanization (left top: proportion of urban population; left bottom: built-​up areas development) and GBA river network (right) 12.2 Word frequency count for Policies and Newspapers 12.3 Comparison of the Dasha before and after rehabilitation (top left: 1977; top right: 2022 12.4 Top: Combined sewer overflow section in Dasha in Phase II (above) and Phase III (below). Bottom: Combined sewer overflow in Phase II (left) and Phase III (right) 13.1 Cooperative landscape 14.1 Land use and land cover change map of Dhaka for the years 1990, 1995, 2000, 2005, 2010, 2015, and 2020 14.2 Area and proportion of different land use and land cover (LULC) types of Dhaka City in different years 14.3 Water intrusion into Dhaka City Roads due to poor drainage 14.4 Illegal encroachment in Dhaka City 14.5 Dhaka City experienced severe flooding due to heavy precipitation 14.6 Inappropriate solid waste disposal in Dhaka City 14.7 Diverse green infrastructure options for flood management 15.1 Geographical focus of the case studies in Africa (right) and Asia (left) contained in the book

160 169 171 173 186 187 188 189 189 190 191 202 209 211 212 222 232 233 234 234 235 235 238 246

Tables

1.1  Comparison of share of urban population and level of urbanization by Asia and Africa (2020–​2050) 3.1  Plant species diversity and its economic importance of EKW region 3.2  Status of some important fauna species within EKW region 3.3  Multiple wetland ecosystem services provide from EKW region 3.4  Transformation of land use land cover in EKW region within the research period (1975–​2021) 3.5  Ecosystem service values (ESVs) in per unit area (ha) of different unit values or value 3.6  Estimated ecosystem service values (ESVs) (million UDS yr-​1) using various unit values in respective years (1975, 2000 and 2021) 3.7  Status of ecosystem service values (ESVs) for each LULC classes (1975, 2000 and 2021) using various unit values 3.8  Area under curve (AUC) statistics of the used machine learning models based on validation datasets 4.1  Satellite remote sensing data used 4.2  Determinants of average irrigation deficit 5.1  The use and services of submarine ground water 6.1  A comparison of migration patterns due to water-​related issues in South Asia and Africa 7.1  Overarching water sector governance institutions, their roles, and guiding institutional framework for Malawi 8.1  Indicators and variables for inter-​ward assessment by assigning weights and preparing a composite index 8.2  Composite index score from the indicators scored as per thresholds given in Annex A 8.3  Spatial characteristics of the surveyed wards

3 26 27 28 30 31 38 39 43 55 64 74 96 117 135 138 141

xiv  List of tables 10.1  The trend of sedimentation -​erosion of estuaries of Ca Mau 10.2  The trend of sedimentation -​erosion of shorelines of Ca Mau 10.3  List of ecosystem services of Ca Mau Cape 12.1  Core policies of Pearl River Delta water management 13.1  Loan options offered 13.2  Adverse selection and moral hazard

174 174 176 206 223 224

Contributors

Partha Pratim Adhikary (PhD) is a Senior Scientist at ICAR-​Indian Institute of Water Management, Bhubaneswar, India. He obtained his PhD in Agricultural Physics from ICAR-​Indian Agricultural Research Institute, New Delhi, India. His research interests include solute transport, soil and water conservation and management, pedotransfer functions, and geospatial modeling of natural resources. Dr Adhikary has published more than 70 research papers in peer-​ reviewed journals and 8 books. His other publications include book chapters, popular articles, technology brochures, technical bulletins, and scientific reports. He is the associate editor of Indian Journal of Soil Conservation. He is also the guest editor of “Environmental Science and Pollution Research” and “Applied Water Science”. Currently, he is the editor of Springer-​Nature book series GIScience and Geo-​environmental Modelling. Ram Avtar (PhD) is working as Associate Professor at the Faculty of Environmental Earth Science, Hokkaido University, Japan. He developed methods for forest mapping using multi-​sensor remote sensing techniques and scenario analysis for sustainable forest management. His research interest is in applications of Geospatial techniques to monitor terrestrial ecosystems including forest, agriculture, urban and disasters and disseminating the results to policy-​makers. Currently, he is working on the synergistic use of remote sensing and Unmanned Aerial Vehicles (UAVs) techniques to monitor the environment more precisely to solve environmental issues from global to local scale. Shib Sankar Bagdi is an Urban and Regional Planner, holding a Master’s degree in Urban and Regional Planning (MURP) from School of Planning and Architecture, Bhopal (2019-​2021). And completed Bachelor’s and Master’s degrees in Geography from Visva-​Bharati, Santiniketan. His thesis focused on Accessible Health Care Services. He excelled in UGC-​NET exams in 2021 and 2023, and completed a course on ‘Geospatial Inputs for Enabling Master Plan’ organized by IIRS Dehradun. With interests spanning Urban Governance, Regional Development, Urban Fringe dynamics, Urban Finance, Transportation, and Remote Sensing, he thrives on challenges and seeks continuous learning.

xvi  List of contributors Biswajit Bera (PhD) is an Assistant Professor in the Department of Geography, Sidho-​Kanho-​Birsha University, Purulia (India) and as visiting Professor in the Department of Geography, University of Calcutta and Alia University. Dr. Biswajit Bera has rich experience in teaching in different core areas of Geography at various colleges and universities over the last 16 years. His field of interest is Geomorphology, Environmental Geography and Hydrology. He is the recipient of prestigious Young Geomorphologist Award in 2008 (India) and International Young Geomorphologist Award (Australia) in 2009. Dr. Bera has published several research articles in both the National and International peer reviewed journals. Now, he is also a guest editor of MDPI and SPRINGER journals. Sumana Bhattacharjee (PhD) is an Assistant Professor and head in the Department of Geography, Jogesh Chandra Chaudhuri College under University of Calcutta, West Bengal (India). Her fields of research interest are Geomorphology, Hydrology and Environmental Geography. Dr. Bhattacharjee has also published a book on Bio and environmental Geography for UG and PG level students. She has published several research articles in National and International peer reviewed journals. She is executing the duty of reviewer for various journal publication houses like Wiley & Sons, Springer, Taylor & Francis, Elsevier and Nature. Shamik Chakraborty (PhD) is an associate professor at the Graduate School of Advanced Sustainability Science, University of Toyama, Japan. Prior to this he has worked as a Lecturer at the Sustainability Co-​creation Programme at Hosei University, Japan. He has also served as a JSPS-​UNU postdoctoral fellow at the United Nations University, Institute for the Advanced Study of Sustainability (UNU-​IAS), and as a visiting research fellow at the Integrated Research System for Sustainability Science (IR3S) (presently, Institute for Future Initiatives) at the University of Tokyo. As a human geographer, he is interested in studying human-​environment interactions from a social-​ecological systems perspective. He has worked with the concepts of social-​ecological systems, local ecological knowledge, and ecosystem services in different ecosystems in Japan, India, Bangladesh, Nepal, Indonesia, and the Philippines. Amit Chatterjee (PhD) has a combined experience of more than one and half decades in teaching, research and industry and is presently an Associate Professor in the Department of Geography at Visva-​Bharati University, Santiniketan, India. His research interest includes urban sustainability, land and environment. Dr. Amit has completed successfully a number of collaborative research and consultancy projects, including those on Urban Co-​benefits (UNU-​IAS, Japan), Urban Missions in India-​targets, performance and linkages to UN-​SDGs (GIZ), Politics of Care in Pandemic Time (UCL’s Global Engagement Funds), Urban Biodiversity (UNU-​IAS, Japan), Shelter for All under Design Innovation Centre (Govt. of India).

List of contributors  xvii Linda Chinangwa (PhD) is the Deputy Country Director of WeForest Malawi, an organization whose mission is to conserve and restore the ecological integrity of forests and landscapes. Passionate about sustainable development, her career extends across various divisions of sustainable development and natural resources management including extension service provision, policy development, research, and programme management for several national and International Organizations, including as the Project Manager for UNDP_​ UNEP Poverty-​Environment Action for SDG project, a JSPS-​UNU postdoctoral fellow at the United Nations University, Institute for the Advanced Study of Sustainability (UNU-​IAS), and as a visiting research fellow at the Integrated Research System for Sustainability Science (IR3S) (presently, Institute for Future Initiatives) at the University of Tokyo. She has also worked for the Malawi government as Chief Land Resources Conservation Officer as and as an independent consultant for several organizations. As a Conservation Biologist, she is interested in studying the social impact of conservation approaches and engaging communities in the development and implementation of lasting environmental and social initiatives. Walter Chinangwa is the Country Lead for Water Witness International -​Malawi, an organization dedicated to addressing the global water crisis. A seasoned climate resilience and water security expert, he specializes in delivering impactful community and private sector water stewardship, climate adaptation and resilience programs across Malawi and the East Africa region. As such he has has successfully led the implementation of the Alliance for Water Stewardship Standard in Malawi, served as an advisor for the Alliance for Water Stewardship Africa Advisory Group. He has also provided technical advice and coordination support to the Malawi Government for the fulfilling of the Country’s commitments of the Fair Water Footprints Declaration. With a Master’s degree in Development Studies, he is deeply passionate about contributing to sustainability in all development initiatives. Kousik Das (PhD) is an Assistant Professor at the Department of Environmental Science and Engineering, SRM University-​AP, Guntur, India. Prior to this he was a postdoctoral fellow at the Center for Water Supply Studies, Texas A&M University-​Corpus Christi, USA. He has completed his PhD from School of Environmental Science and Engineering, IIT Kharagpur, India. His major research interest lies in Solute geochemistry, Surface water-​ groundwater interaction, Submarine groundwater discharge (Coastal hydrogeology). He is currently engaged in two DST-​funded major projects. He has more than 30 international publications in reputed journals. He has presented his work in several international forums like in Goldschmidt, USA. He is a member of the International Association of Hydrogeologists and the European Association of Geochemistry. Rajarshi Dasgupta (PhD), is currently working at Institute for Global Environmental Strategies (IGES). A graduate from Kyoto University,

xviii  List of contributors specializes in landscape ecology and environmental science. He holds diverse research interests in the field of landscape ecology and planning, which include Ecosystem-​based Disaster Risk Reduction (Eco-​DRR), spatial quantification of ecosystem services, land change simulation, development of socio-​ecological scenarios, participatory conservation, and social forestry. Nigel K. Downes (PhD) Nigel K. Downes studied geography in the UK and environmental management in Germany. He has been working as an integrated expert at the College of Environment and Natural Resources, Can Tho University in a position supported by German development cooperation since 2020. His work focuses on environmental planning, the development of monitoring and indicator assessment and embedding spatial climate adaptation solutions into planning frameworks. Chokri Dridi (PhD) is Associate Professor at the Institut Sociétés & Humanités (ISH) and Laboratoire de Recherche Sociétés & Humanités (LARSH), Université Polytechnique Hauts-​de-​France (UPHF), France. Prior to this he was Assistant professor at the University of Alberta, Canada. His primary areas of research are environmental and resource economics and industrial organization, both applied and theoretical. After a Bachelor in Economics and graduate studies in Mathematical Economics and Econometrics in Tunisia, He received his MSc and PhD in Agricultural and Consumer Economics with specialization in environmental and resource economics from the University of Illinois at Urbana-​Champaign, USA. His current research is on water use efficiency and environmental regulation. Druti Gangwar is a PMRF Doctoral Researcher at Department of Architecture and Planning, IIT Roorkee, India. She has a B. Plan from SPA Bhopal and MSc. from ITC-​University of Twente, The Netherlands. She is a recipient of proficiency gold medal (B. Plan) and the ITC Excellence Scholarship (MSc.). She has conducted research with national and international organizations based in India, Netherlands and Suriname (South America). She specializes in Geoinformation Science and Earth Observation and applies it for studying natural resources in urban settings. She has multiple journal and conference publications related to the urban planning and management of urban environment. Nagham Ismaeel is a Ph.D. student at Department of Environmental Science and Engineering, SRM University-​AP, interested in climate change and coastal hydrogeology. She holds an M-​Tech in Energy and Environmental Management from Jain-​deemed to be-​University, Bangalore, India, and a Bachelor of Science in Marine Geology from Tishreen University, Lattakia, Syria. Md. Asif Bin Kabir is an Assistant Professor in the Department of Civil Engineering at United International University (UIU), Bangladesh. His research interest lies in the area of sustainable infrastructure design under dynamic loading, numerical analysis of structures, large scale experiment, application of artificial intelligence (AI) in civil engineering domain. His research experience includes

List of contributors  xix working on industry (CISC, NSERC) funded projects with strong publication record for both journal and conferences. He is a recipient of several awards and scholarships from both home and abroad. Mr. Asif has both academic and industrial experiences throughout his professional career. His industrial experience includes serving as a structural design engineer in a consultancy firm in Bangladesh. He has supervised multiple significant projects and provided consultancy services for the local industries. He has active industry-​academia collaborations. Last but not the least, he has multiple research collaborations in different domains with various researchers around the world. Mohamed Kefi (PhD) is assistant professor at Water Research and Technologies Center (CERTE). He obtained his PhD from the University of Tsukuba, Japan in 2011. From 2016 to 2018, he served as UNU-​JSPS Postdoctoral Fellow at the UNU-​IAS/​The University of Tokyo Institutes for Advanced Study. His main research interests are water resource management, natural hazards, ecological economics, GIS and remote sensing applications. Dr. Kefi has research experiences in several countries: Tunisia, Japan, Vietnam, the Philippines, India and Indonesia. He published several scientific papers on water and environment issue and natural disaster and he participated in many international conferences around the world. He is also NCP Marie Skłodowska-​Curie Actions (MSCA) Horizon Europe. Md. Ayatullah Khan is a doctoral researcher at the Department of Geography, Hong Kong Baptist University, Hong Kong. He holds master’s and bachelor’s degrees in Development Studies from Khulna University, Bangladesh. As part of his professional career, he has worked at United International University, Bangladesh as an adjunct faculty member, and at Institute of Informatics and Development, Bangladesh as a researcher, and at CARE Bangladesh as a humanitarian and development activist. Furthermore, he is engaging in multiple research collaborations with various researchers. His research interests, but are not limited to, include vulnerability assessment, climate change and disasters, flood management, and urban development. Harisankar Krishnadas works at the World Benchmarking Alliance as a Research Analyst and is a member of the Urban Team. He actively contributes to the development of the Urban Benchmark, directing his efforts towards promoting corporate accountability to create sustainable and resilient cities. Harisankar acquired substantial expertise in sustainable urban development, disaster risk reduction, and governance while holding roles at organizations like Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ), United Nations, World Bank, and Delhi Government. His experience spans across South Asia, Southeast Asia, Africa, and North America. Pankaj Kumar (PhD) is working as senior policy researcher in the field of water resources and climate change adaptation in the Institute for Global Environmental Strategies (IGES), Japan. Prior to this, he worked as JSPS/​UNU-​IAS postdoctoral fellow in United Nations University, Institute for Advanced Study of

xx  List of contributors Sustainability (UNU-​IAS), Tokyo; for more than three years. His research work focused on socio-​hydrology, water security, hydrological simulation and scenario modelling, and water-​health-​food-​energy nexus, a transdisciplinary work aimed to give policy relevant solutions to enhance community resilience to global change and a sustainable development of water environment and human well-​being. In addition, he is actively engaged in capacity development on various numerical tools used for water resource management, intended for local government officials and relevant stakeholders in different Asian countries. He has work experience with different global assessments like IPCC, IPBES and GEO as Chapter scientist and lead authors respectively. He has several peer reviewed articles (>170) in high impact factor journals, one authored book, one edited book to his credit. Kim Lavane (PhD) is currently a senior lecturer of Environmental Engineering, at the Department of Environmental Engineering, at Can Tho University. He received a BS in Environmental Engineering from the University of Technology-​ Vietnam National University Ho Chi Minh, Vietnam. His MS and Ph.D. degree is in Civil Engineering from the University of Hawai′i at Manoa, USA. Dr. Kim started his career at Can Tho University in 2003. His research topics cover water quality, environmental microbiology, biological treatment for wastewater and organic waste, and environmentally friendly remediation technology. In 2023, Dr. Kim has officially recognized as an Associate Professor in Environmental Resource Management. Kristina Matysik is a senior consultant within the Energy, Sustainability, and Infrastructure practice at Guidehouse. Her current work focuses on connecting with stakeholders to develop actionable roadmaps to assist underserved communities. Prior to working at Guidehouse, Kristina completed her Master of Public Policy at the University of Chicago. Her studies focused on development economics and behavioral science. She is deeply passionate about advancing climate action while ensuring an equitable transition to a clean economy. Gowhar Meraj (PhD) is currently working as JSPS postdoctoral fellow in University of Tokyo, japan. He works in the field of remote sensing, GIS, watershed management, hydrology, disaster risk assessment and mitigation, simulation modeling, and spatial analysis. He holds a Ph.D. Degree in Environmental Sciences, specializing in climate change and water research, and his research is mainly focused on the interface of ecosystem services modeling, hydrology, glaciology, natural hazards, and watershed management. Huynh Vuong Thu Minh, Ph.D., is currently a senior lecturer at the Department of Water Resources, CENRes, Can Tho University. She has 20 years of experience in teaching and doing research related to Climate, Hydrology, and Water resources. She earned her Ph.D. degree in the Graduate School of Environmental Science at Hokkaido University, Japan in 2019. Dr. Thu Minh was officially recognized as an Associate Professor in Irrigation Water Management in 2023.

List of contributors  xxi Binaya Kumar Mishra (PhD) is currently engaged as a full-​time professor at the School of Engineering, Pokhara University, Nepal. Prior to this, he worked as a research fellow at the United Nations University, Institute for the Advanced Study of Sustainability (UNU-​IAS), Tokyo. He is involved in research and teaching activities for Bachelor (Civil Engineering) and Master (Hydropower Engineering; Public Health and Disaster Engineering) programs. His research and teaching interests include water resources management; climate and ecosystem change adaptation; hydrologic and environmental modeling and applications of GIS and remote sensing. Prior to joining Pokhara University, he briefly worked as an associate professor at the Central Campus of Engineering, Mid-​Western University, Nepal. Earlier, during October 2009–​March 2018, he worked as a researcher and faculty member at different academic institutions in Japan. He also worked as an irrigation engineer at the Ministry of Irrigation; a senior lecturer at Kathmandu Engineering College, Tribhuvan University, and a consulting engineer at Kathmandu, Nepal, during 1999–​2006. His research works have been published in several books, journals, reports and proceedings. Geetha Mohan (PhD) is a Professor at University of Toyama, Japan. His major research interests are agricultural economics, economics of climate change, adaptation strategies, and crop simulation models. He holds his Ph.D. in Economics from India. Before joining the University of Toyama, he worked as a Research Fellow at UNU-​IAS; and an Assistant Professor for more than four years and one year as a project researcher at the Integrated Research System for Sustainability Science (IR3S), The University of Tokyo, Japan. He was a JSPS Postdoctoral Fellow at UNU-​ISP (one of the institutes that merged to form the current UNU-​IAS) from 2009 to 2011. He has diverse international and national experience, including roles as a Visiting Scientist at ICRISAT, Research Analyst at NCEAR, and Research Investigator at AERC in India. He also served as a Field Supervisor at CESS in India and as a Research Investigator (field) with the Centre for Development Research in Germany. Nguyen Dinh Giang Nam, Dr. Nguyen Dinh Giang Nam has been working at Can Tho University since 2004 and currently holds the position of the Head of the Department of Water Resources, College of the Environment and Natural Resources. He graduated a Master’s degree at the Technology University of Braunschweig, Germany in 2009. He finished his PhD in 2017 at the Tokyo University of Agriculture and Technology, Japan. Dr. Giang Nam has been awarded and official recognized as an Associate Professor in Environmental Resource Management. Rama U Pandey (PhD) is a Professor and Head of the Landscape Department at the School of Planning and Architecture in Bhopal, India. She also leads the National Centre for Spatial Rural Development Planning (NCSRDP), which the Ministry of Panchayati Raj, Government of India established. Dr. Rama is an architect and environmental planner by training. She has experience working in academics and industry in Architecture and Planning for over two and a half

xxii  List of contributors decades. Industry experience includes both commercials as well as large-​scale residential projects. Her research interest in academics is primarily focused on Climate-​informed settlement planning, Mainstreaming ecosystem services in planning, Socio-​ecological and climate change resilience, and Livability of the residential built environment. She has contributed as an environmental planner in SPA Bhopal’s Multinational and National projects in Climate resilience, Regional Planning, and Rural Spatial Planning. Md. Mujibur Rahman is a Professor at United International University and former faculty at BUET, holds a Ph.D. from the University of Adelaide and a Master’s from the University of Melbourne. With expertise in Climate Change’s Impact on Water and Sanitation, Water Supply, and Wastewater Engineering, he has led national initiatives, including the development of the Hatirjheel project in Dhaka. Prof. Rahman’s research focuses on various aspects such as climate change impacts, ecological sanitation, and water quality assessments. He actively contributes to international collaborations, notably the EU-​funded project on environmental sanitation in South Asia. With extensive affiliations and contributions to engineering education and research in Bangladesh, he exemplifies commitment to national development in the water supply and sanitation sector. Richa holds a Ph.D. in Economics from IIT Roorkee, India, with a dissertation titled “Climate Change induced Migration: An Evidence based study in the selected districts of North Bihar.” Currently, she serves as a Senior Program Associate at WRI India, where she supports climate modeling projects. Her research focuses on understanding the impacts of climate change on migration patterns, contributing valuable insights to environmental and socio-​economic research. Shantanu Kumar Saha is an academic with a diverse background in both science and social science. He has been working in academia since 2008 and has experience in national and foreign institutes. He is currently employed as an Assistant Professor at United International University (UIU) in Bangladesh, where he teaches graduate and undergraduate courses. In addition to his academic career in Bangladesh, Dr. Saha has worked as a research fellow at the Institute for Sustainable Futures at Keele University in the UK and as an intern at the Centre for Non-​Traditional Security Studies at Nanyang Technological University in Singapore. Dr. Saha has a Ph.D. in Asia Pacific Studies with a concentration in Social Science focusing on Environment and Development Studies and a Master of Science in International Cooperation Policy majoring in Environmental Policy and Administration from Ritsumeikan Asia Pacific University in Japan. Throughout his academic journey, he has received prestigious accolades, including Association of Commonwealth Universities (ACU) fellowship, Ryoichi Sasakawa Young Leaders Fellowship (Sylff); Monbukagakusho Honors Scholarship, The Fuji Xerox Setsutaro Kobayashi Memorial Fund. He has conducted research on various topics such as climate change adaptation, poverty alleviation, women empowerment, and sustainable

List of contributors  xxiii development and has published papers in academic journals, a book from an international publisher (Routledge), book chapters, and research reports. Soumik Saha is a PhD Scholar in the Department of Geography, Sidho-​Kanho-​ Birsha University, Purulia (India). He has completed Post Graduate degree from the department of Geography, University of Calcutta. His fields of research interest are Climatology, Hydrology, Environmental Geography and Geomorphology. Mr. Saha has highly involved in applied research particularly on geotechnical investigation of landslide hazard and management in Garhwal Himalaya, India. He has published several research articles in National and International peer reviewed journals. She is performing the duty of reviewer for many journal publication houses like Wiley & Sons, Springer, Taylor & Francis and Nature. Osamu Saito (PhD) is currently working as principal policy researcher in the Global Environmental Strategies (IGES), Japan. As an expert in the field of biodiversity and ecosystem services, Osamu Saito has been working on the interlinkages between ecological, human and social systems through sustainability science approaches. His research experiences include socio-​ecological studies on the ecosystem services provided by traditional rural production landscapes (Satoyama) in both Japan and other Asian countries. He worked for for the Advanced Study of Sustainability (UNU-​IAS) as Academic Director from 2011 to 2020. He has been also actively promoting various activities for Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) as a lead author of both regional and global assessments. He has been a managing editor of the Sustainability Science journal published by Springer since 2011. Subir Sen (PhD) is Associate Professor in the Department of Humanities and Social Sciences and Joint Faculty in the Centre of Excellence in Disaster Mitigation and Management (COEDMM) at the Indian Institute of Technology Roorkee. His research areas include Economics of risk and uncertainty, Insurance economies, and Economics of climate change and disasters. He was visiting professor at DPRI, Kyoto University and Keio University in Japan and special invite for University Immersion Programme of IDMR, Sichuan University, China. He earlier served TERI University, New Delhi and Madras School of Economics, Chennai. He was a Member of the Board of Governors, Asia Pacific Risk and Insurance Association (APRIA) (2019-​2022), Secretary (2022-​2024) and Joint Secretary (2020-​2022) of the Indian Society for Ecological Economics (INSEE). He received distinguished awards such as the JSPS-​ICSSR Joint Research Project, GDN’s Japanese Outstanding Research on Development (ORD), subsidy from the Geneva Association, etc. He contributed to sponsored research by the Govt. and International agencies like Ministry of Agriculture, Govt. of India, IRDAI, SANEI, APN, DST-​CHORD, IFC, World Bank Group and UK NERC. He has peer-​reviewed publications to his credit. Debashish Sengupta (PhD) is working as Professor, Higher Administrative Grade and Former Head of the Department of Geology and Geophysics in

xxiv  List of contributors Indian Institute of Technology (IIT) Kharagpur, West Bengal, India. Prof. Sengupta has more than 30 years of teaching and research experience. He has completed his PhD in 1987 in Applied Geophysics. His areas of interests are nuclear geophysics including petroleum logging using subsurface nuclear data, radioactive methods and geochronology, radon emanometry and its applications, applications of isotopes and radionuclides in earth and environmental geosciences, heat flow and geothermics. Prof. Sengupta has 110 research publications in international journals and more than 60 papers in Conference Proceedings apart from a large number of Invited Talks delivered both in India and abroad. The research work has been seminal and resulted in the formulation of Environmental Regulation policies in various countries both in India and countries like USA, South America and the European Union. Prof. Sengupta had also been a Visiting Professor at the University of Sao Paulo, Brazil and as Senior Visiting Professor at the University of Salamanca, Spain, earlier, while on a sabbatical leave from the institute. He has received Society of Geoscientists and Allied Technologists (SGAT’s) Award of Excellence in Earth Sciences for the year 2003. Prof. Sengupta has published four (05) books. Nairita Sengupta is a PhD scholar in the Department of Geography, Diamond Harbour Women’s University, West Bengal (India). Her fields of research interest are Hydrology, Environmental Geography and Geomorphology. Ms. Sengupta has also published a book on Bio and environmental Geography for UG and PG level students. She has highly engaged in applied research particularly on quality of water resource assessment and management in dryland region of India. She has published several research articles in National and International peer reviewed journals. She is executing the duty of reviewer for many journal publication houses like Wiley & Sons, Springer, Taylor & Francis and Nature. Di Shao is a PhD candidate in the Department of Architecture and Civil Engineering at the City University of Hong Kong. She holds a Master of Urban Design and Regional Planning from the same institution and a Bachelor of Landscape Architecture from Beijing Forestry University. Di has a keen interest in the production of public spaces and users’ rights. Her recent research focuses on the production of riverside spaces and the historical process of urban river governance in China. Pravat Kumar Shit (Ph.D) is an Assistant Professor at the PG Department of Geography, Raja N. L. Khan Women’s College (Autonomous), West Bengal, India. He received his M.Sc & Ph.D. degrees in Geography from Vidyasagar University and PG Diploma in Remote Sensing & GIS from Sambalpur University. His research interests include applied geomorphology, soil erosion, groundwater, forest resources, wetland ecosystem, environmental contaminants & pollution, and natural resources mapping & modelling. He has published twenty-​three books (Springer-​18, Elsevier-​04, CRC Press-​01) and more than 90 papers in peer-​reviewed journals and 85 book chapters. He is also the guest

List of contributors  xxv editor of “Environmental Science and Pollution Research” and “Applied Water Science”. He is currently the editor of the GIScience and Geo-​environmental Modelling (GGM) Book Series, Springer-​Nature. Kazuhiko Takeuchi (PhD) is currently serving as president of Global Environmental Strategies (IGES), Japan. Before this, he served as professor at The University of Tokyo and as Director and Professor, Integrated Research System for Sustainability Science (IR3S) at The University of Tokyo. He also served as a Vice-​Rector and Senior Vice-​Rector at United Nations University from 2008 to 2016 and as an Assistant Secretary-​General at the United Nations from 2013 to 2016. He has served, inter alia, as Acting Chair of the Central Environment Council; and Chair of the Nature Conservation Committee of the Central Environment Council, Government of Japan, Editor-​in-​Chief of the journal Sustainability Science (Springer Nature), and Distinguished Chair, Wangari Maathai Institute for Peace and Environmental Studies, University of Nairobi. He received the 2021 MIDORI Academic Prize in 2021, Ichimura Prize in Science against Global Warming for Distinguished Achievement in 2019, Otto Soemarwoto Award (Indonesia) in 2018, Japan Prize of Agricultural Science in 2017, Ishikawa Award of the City Planning Institute of Japan in 1994, Award of the Association of Rural Planning, Japan in 1994, and Award of the Japanese Institute of Landscape Architecture in 1980. He specializes in landscape ecology, environmental studies, and sustainability science. He engages in research and outreach activities on creating eco-​friendly environments for a harmonious coexistence of people and nature, especially focusing on Asia and Africa. Gianni Talamini, PhD, is an associate professor at the Department of Architecture and Civil Engineering, City University of Hong Kong. He completed his PhD in Urbanism with full marks at the IUAV University of Venice under Professor Bernardo Secchi. He also holds a Master’s in Architecture from the same university. Before joining City University, he served as a Postdoctoral Fellow at the Harbin Institute of Technology, Shenzhen. Gianni explores the synergy between the built environment and nature through scientific analysis and research by design. He works for an environmentally symbiotic, culturally leavened, and spatially just society. Le Anh Tuan, Dr. Le Anh Tuan has been working at Can Tho University since 1982 and currently holds the position of Senior Lecturer at the College of Environment and Natural Resources. He finished his PhD. in 2008 at Catholic University of Leuven, Belgium. In 2012, Dr. Tuan was official recognized as an Associate Professor in Earth Sciences. He also is the Scientific Advisor of the Research Institute for Climate Change –​Can Tho University (DRAGON inst. –​ Mekong), Vietnam. Tran Van Ty, Dr. Tran Van Ty has been working at Can Tho University since 2002 and currently holds the position of Senior Lecturer at the Faculty of Water Resource Engineering, College of Engineering. He finished his PhD. in 2011 at

xxvi  List of contributors the University of Yamanashi, Japan. In 2020, Dr. Ty was official recognized as an Associate Professor in Water Resources. Tomoki Yagasaki is currently working at Institute for Global Environmental Strategies (IGES). A graduate from Yokohama National University, specializes in vegetation ecology and environmental education. His current research works mostly centered around forest resource conservation, degraded land restoration, and environmental education etc. He is also actively engaged on different capacity development programs in Asia and Africa.

Preface

A growing academic and policy literature recognizes that the key to sustainable development in urban environments involves growth in an economy that is within ecological limits. However, there is still a lack of clear understanding of how the ecological limits fit in an urban context. The book presents insights into interlinkages between water-​food-​health-​human well-​being-​climate change in an urban context from water as an entry point. It combines theoretical perspectives from socio-​ecological or socio-​hydrological systems to bring learning points through case studies. The studies in this book extend the understanding of water conservation and restoration in Asia and Africa, blending perspectives from both theoretical and empirical studies to bring out biophysical, and socio-​political dimensions of water ecosystems. These include studying socio-​hydrology, human health risks, population displacement and migration, water pollution, water scarcity, flood management, water infrastructure, afforestation, effects of climate change, and conservation for assessing sustainable transformative changes in urban contexts. The book suggests a holistic framework and multidimensional positions with case studies ranging from different geographies to extend thinking and application of environmentally rooted and water ecosystem-​based urban development. The book is divided into five main parts. The introductory part deals with the approach and focus of the volume. The subsequent parts deal with (a) states and impacts, (b) development challenges, (c) valuation, and (d) effective policies and planning on the management of urban water ecosystems, before concluding the key understanding and recommendations from the different case studies in Asia and Africa. The book will be of interest to researchers, students, and policymakers working on sustainable urban development based on designing and conservation of water ecosystems in urban areas. The book will be of particular interest to undergraduate and postgraduate students who are working on conservation/​restoration and sustainable use of river basins and water ecosystems.

xxviii  Preface The book could not have been prepared without contributions from a diverse set of researchers who contributed in this book. The editors would like to thank all the chapter contributors for their chapters. The editors would also like to extend their special thanks to the experts who commented on the edited volume. Shamik Chakraborty (Toyama, Japan) Amit Chatterjee (Santiniketan, India) Pankaj Kumar (Hayama, Japan)

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Acknowledgements

We would like to thank all the contributors to this edited volume, whose rich insights on urban water and ecosystem issues were a major catalyst for the development of this interdisciplinary work. The major part of this book project was undertaken with the editors’ involvement at the University of Toyama, Graduate School of Advanced Sustainability Science, Institute for Global Environmental Strategies, and the Department of Geography, Visva Bharati University. Shamik Chakraborty is grateful for the support of the Asia Pacific Network for Global Change Research project “Interlinkage of Ecosystem Services and Human Wellbeing to Enhance Climate Smart Landscapes in Small Watersheds: Analysis for Policy-​Relevant Solutions in South Asian Context” (Grant No: CRRP2019-​ 04MY-​Chakraborty). Shamik Chakraborty and Amit Chatterjee are grateful to the Japan Society for the Promotion of Science-​Indian Council of Social Science Research (JSPS-​ICSSR)-​bilateral research fund on the project “Restoration and conservation of wetlands near urban areas with the help of traditional and local knowledge and citizen science”. Finally, last but not least, we would like to thank the editors at Routledge, for their kind help, support, and continuous encouragement throughout the production process of this book.

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From urban water resource management to urban water ecosystem management Shamik Chakraborty, Amit Chatterjee, and Pankaj Kumar

1.1  Setting the stage: water and urbanization in Asia and Africa In the arid part of the Indus Valley in South Asia, archaeologists in 1921 and 1922 unearthed the remains of a great civilization with possibly two highly advanced urban areas, one at Harappa (to the upstream of the Indus) and the other at Mahenjodaro (downstream of the Indus), in present East Pakistan. Each of these ancient urban areas may have housed as much as 35,000 people. In the later years, other nodes of the civilization were discovered, that stretched as far as from southwest Balochistan in the east to The Yamuna River near Delhi in the west, and the Gulf of Cambay in the south. In addition to its extensiveness, the Indus Valley civilization was a highly complex one with its own written languages, measuring units, currency used for trade and still largely unknown pictographic language. The archaeological finds suggest a complex urban structure at Harappa and Mahenjodaro with centralized water distribution and harvesting schemes that predate 19th-​ century water engineering by 4,000 years (Solomon, 2010). However, the civilization was also in an area prone to changes in its geo-​environmental conditions, such as the shifting of the Indus River system and changes in aridity in the area. This factor probably is thought to be one factor behind its unexpected fall around 1,700 years ago (Solomon, 2010). The example of Harappa and Mahenjodaro gives a strong indication that freshwater has been a significant factor in urban growth and development since historic times. Water-​related breakthroughs, on the one hand, helped develop urban areas and society since historic times, and on the other, perhaps also decided their downfall. If we fast forward to time during the Industrial Revolution, we see that many of the water-​industry and water-​agriculture links were established at the expense of ecosystem decline. For example, water-​related technology such as the steam engine made mining of coal and irrigated agriculture possible, thereby supporting a significant increase in population, which in turn supported industrialization and urbanization but at the same time became a slow time bomb that would degrade much of biodiversity and overexploit resources that are fundamental for our very existence in the planet (Erlich, 1978). In urban areas –​either in ancient times or the present –​freshwater represents prominent examples of being a subset of complex socio-​ecological interactions between ecosystems and people. This implies DOI: 10.4324/9781003437833-1

2  Urban Water Ecosystems in Africa and Asia that if these socio-​ecological relations are not resilient enough, the urban areas can experience interlinked socio-​environmental problems such as water scarcity, food insecurity, diseases, conflicts due to water, unsustainable migration, and increasing poverty, among others. However, rapid urbanization in the global south, particularly in Asia and Africa, has put tremendous pressure on the remaining freshwater environments in these two continents. Most tell-​tale pressures are from modification and alteration of freshwater environments, damming, river and stream channel modification, increase in impervious surfaces, disconnected waterways, and increasing pollutants, among others. These induce impacts such as human health hazards, conflicts, and migration from areas that are self-​reliant, such as traditional agroecological landscapes. All these pose serious challenges for freshwater-​related policies in urban areas. Asia and Africa consist of a vast region of significance in the above context. The region is also seeing some contrasting urbanization patterns while both continents are undergoing a high urbanization rate. For example, while large urban agglomerations have taken place in Asia, these agglomerations are emerging in Africa, many in ecologically fragile areas or areas of rich ecosystems, such as estuaries and deltas. Also, urbanization in Asia and Africa has some similar trends as both of these continents show urban patterns that are messy and hidden, not often reflected in published reports and statistics. Business as usual for these two vital regions, particularly which are based on limited information and understanding of urban water ecosystems will have significant repercussions for the already dwindling and heavily stressed freshwater environments. For example, fragmented land development, sprawls, and ribbon developments have consumed land around major cities (Wang and Kintrea, 2021). With the impact of climate change and its induced frequent extreme weather conditions and higher-​order interactions between water-​ food-​health-​human well-​being-​climate change-​land, this nexus has become more complex to address. Although several countries in Asia and Africa have formulated regulatory frameworks, including policies and missions for conserving and managing urban lakes and wetlands; however, interventions that consider urban water as a subset of urban water environments (i.e., the ecosystem component) are still lacking (Murti & Mathez-​Stiefel, 2019, Mishra et al. 2020, Nguyen et al., 2019) –​with very few studies done on urban freshwater environments in these two regions taken together –​in spite of the recent call for applying an ecosystem-​based approach and nature-​based solutions to development planning, including in urban areas (UNEP, 2024; WWF, 2020, Snep et al., 2020). 1.2  Urbanization in Asia and Africa The urban era began in the 21st century, marked by a notable shift in global urbanization toward southern regions. The global south saw a significant increase in urban development in the second half of the 20th century, in contrast to Europe and North America, where it started in the 1800s following the Industrial Revolution. Nevertheless, in 2020, there were about 2.4 billion people living in Asia’s cities –​a

Urban water resource to ecosystem management  3 number that is expected to rise to 3.5 billion by 2050. It is predicted that in the next three decades, until 2050, almost 90 percent of the world’s new urban residents will come from these rapidly expanding Asian settlements. Currently, over half of the world’s population –​that is over 56 percent lives in cities, and this trend of urbanization is only getting stronger, especially in Africa and Asia. According to projections, the proportion of people living in urban areas is expected to reach 60 percent by 2030 (United Nations, 2019). A comparison of share of urban population and level of urbanization by Asia and Africa (2020–​2050) is highlighted in Table 1.1 In the next thirty years, Asia is expected to add an additional 1.1 billion city dwellers, while Africa is expected to add 0.9 billion (UNDESA, 2018; Kundu, et al., 2023). In contrast to Asia, where in-​situ urbanization, rural-​urban migration, and city expansion are the main causes of urbanization, Africa’s urbanization is primarily driven by high fertility rates. In the next thirty years, the most significant urban growth and migration from rural to urban areas is predicted to occur in Eastern Africa and Southern Asia. The world’s first megacities appeared seven decades ago, with Tokyo and New York, both in developed nations. Currently, a sizable number of megacities are thriving in Latin America, Africa, and Asia, poised to expand massively and claim the top spots as the largest megacities globally. African megacities are expected to see a significant population boom after Asia, highlighting Africa’s status as the last major continent to undergo widespread urbanization. (Suhail and Najeeb, 2019). Even though it is anticipated that both continents will contribute significantly to urbanization in the future, the paths taken by Asia and Africa will differ notably. People in Asia are concentrated in megacities, a characteristic of Asian urbanization that will continue even if the region’s rate of urban growth slows down. Six of the ten megacities with the highest population density in the world are predicted to be in Asia by 2035, with Delhi expected to have 43.3 million residents and be the most crowded city. As opposed to Asian megacities, African cities have not yet experienced the same level of concentrated urban growth. In contrast, rapid urbanization in African countries will be attributed to persistently high fertility rates, which are fueled by urgent rural-​urban migration and economically stagnant cities. Africa’s working-​age population (ages 15 to 64) is expected to increase by 2.1 billion by the end of this century. Africa’s urbanization, which is Table 1.1 Comparison of share of urban population and level of urbanization by Asia and Africa (2020–​2050) Major 2020 Urban 2050 Urban Growth Rate 2020 Level of 2050 Level of Area, Population Population of Urban Urbanization Urbanization Region (in billion) (in billion) Population (%) (%) (%) (2020-​50)

2035 Mega Cities (10 million +​)

Asia 2.3 Africa 0.5

32 5

3.5 1.5

1.3 1.5

Source: Prepared based on Kundu, et. al. (2023)

51.1 43.5

66.2 58.9

4  Urban Water Ecosystems in Africa and Asia now marked by a dearth of megacities, will follow the Asian trend and witness an increase in megacities’ quantity and size. But in contrast to their Asian counterparts, the majority of the newly built megacities in Africa will function more as ‘consumption hubs’ rather than ‘growth centers’ (Kundu, 2023). The total urbanization rate in Asia, which includes Japan, China, South Korea, Taiwan, Hong Kong, Singapore, Thailand, Malaysia, Indonesia, the Philippines, and Vietnam, increased from 15.3 percent in 1950 to 48.8 percent in 2010. According to projections, this rate is expected to reach 74.4 percent by 2050 and will surpass 50 percent within five years. (Suhail and Najeeb, 2019). 1.3  Challenges in urban water ecosystems Conceptualizing urban water management through an ecosystem-​based approach is not straightforward. A quick example can be given through urban wetlands. Urban wetlands as a concept and term first appeared in the twenty-​first century. The public’s understanding of urban wetlands varies but in general, it is believed that they are wetlands located within urban areas, impacted by human activity in cities, and significantly different in their ecological functions from both natural and artificial wetlands (Li et al., 2022). Covering an area of roughly 29.83 million square kilometers, wetlands make up 5 percent to 8 percent of the Earth’s surface (Mitsch and Mander, 2018). Wetlands are distributed across Asia (9.2 million sq.km), South America (7.95 million sq.km), and North America (5.65 million sq.km), making up 78 percent of the global total. In Africa, wetlands represent 19 percent, totaling 5.6 million square kilometers (Boone and Bhomia, 2018). For human society, wetlands provide a number of vital ecosystem services that are particularly important in areas with high urban population densities (Kometa et al., 2018). Urban populations and wetlands have had a complex and intertwined relationship since the beginning of human civilization. The environment may be negatively impacted by urban areas in a number of ways, with varying degrees of severity and geographical extent. The rapid urbanization and socioeconomic growth have put a great deal of stress on the environment (Cheng et al., 2023). Known for their abundant biodiversity, wetlands have endured loss and continuous degradation over millennia as a result of human activity. They are currently recognized as being lost faster than any other ecosystem. Concerns about contamination, inadequate disposal of waste, encroachment through urbanization, filling or other kinds of construction, and other factors are expressed in the Ramsar Convention regarding the degradation of many wetlands within urban settings (McInnes, 2010). Studies show that since 1900, 64 percent of the world’s wetlands have disappeared, with losses in areas like Asia being especially high. Compared to coastal wetlands, inland wetlands are disappearing more rapidly. The rapid urbanization and demographic shifts that are occurring in many Asian countries place tremendous strain on the current environmental, social and economic structures, making the problems brought on by climate change even more severe (Li et al., 2022). Wetland degradation is greatly impacted

Urban water resource to ecosystem management  5 by the rapid urbanization surge, which increases the need for larger areas for industrial, commercial, and residential use. The conversion of land is causing a decline in the amount of wetlands, vegetation, and green spaces in urban areas (Kadhim et al., 2022; Yang et al., 2022a; Yin et al., 2022a). Some regions in Africa –​the Natal-​Tugela Basin, to be exact –​have lost more than 90 percent of their wetland resources, and the Mfolozi catchment has seen a 58 percent decrease in the amount of wetland coverage. In the same direction, the wetland inventory of Tunisia shows a 15 percent overall loss of wetland area. (Kusler, 1996). Numerous case studies from Asia and Africa show how urbanization affects wetland ecosystem services. For example, Berkessa et al. (2023) in their research on wetlands in Jimma City, Southwest Ethiopia showed that 98 percent of the wetland land cover in the area has disappeared in recent decades as a result of the region’s rapid urbanization and diminishing vegetation cover. The loss of wetlands and water bodies surrounding Bahir Dar City, according to Moisa et al. (2023b), is 1,618 hectares, mostly as a result of the growth of developed and agricultural areas (Assefa et al., 2021). Evaluating how land use and land cover (LULC) impact ecosystem service values (ESVs) is really important for both the public to understand and for making policies. Sharma et al. (2023) assessed how changes in land use and land cover (LULC) impacted ecosystem service values (ESVs) in Chandigarh, India, using satellite imagery from 1990 and 2020. The analysis revealed a 2.54 percent drop in ESVs between 1990 and 2020, which was mostly caused by increased urbanization. The considerable increase in farmland and urban area had a substantial impact on LULC changes, which in turn had an impact on Chandigarh’s ecosystem services. In particular, between 1990 and 2020, the built-​up area increased from 2,386 hectares to 4,882 hectares, resulting in a general change in ESVs over the previous thirty years, primarily indicating a decrease when utilizing the value coefficient from Costanza et al. (1997). The natural environment and the composition of the land have been drastically altered by human activity, which has a detrimental effect on ecosystem function. To comprehend and quantify the impacts of urbanization patterns on ecosystems, Pham and Lin (2023) in their study on Nha Trang, Vietnam, find that over the past three decades, there has been a significant decrease in the value of ecosystem services as a result of expansion and increased density of urban areas. By 2020, the value had dropped to $149.3 million USD a year, mostly due to the rapid expansion of urban areas at the expense of arable land. 1.4  Structure of the book and the main contents This edited volume embarks on a journey to argue for mainstreaming water ecosystems as a pathway to achieve better urban water security in Asia and Africa, without which the socioeconomic development of this vast region can be under threat. The book is divided into six parts. Part 1 (Chapters 1, and 2) sets the stage of the book with the status of urban water management with associated key bottlenecks

6  Urban Water Ecosystems in Africa and Asia of urban water mismanagement. The first part of the book also brings the argument of social-​ecological systems thinking in urban water resource management for integrated planning in urban water ecosystems by exploring the contact points of integrated water resource management (IWRM) and social-​ecological systems (SES). Part 2 (Chapters 3, 4 and 5) deals with the states and impacts of urban water management, while Part 3 (Chapters 6,7 and 8) deals with the specific development challenges that are affecting human well-​being due to changes in the urban water environments. Part 4 (Chapters 9, 10 and 11) deals with the valuation of ecosystems that are within and linked to urban areas, while Part 5 (Chapters 12, 13 and 14) deals with the policies that can lead to better management of urban water ecosystems. Part 6 (Chapter 15) concludes the edited volume by highlighting the main arguments and key takeaways, with an added focus on the future of urban water ecosystem management in Asia and Africa. Below we provide a brief outline of the chapters in this book: Chapter 1 (this chapter) deals with the status and key overviews of urban water resource management in Asia and Africa, discussing the nature of the main challenges, before introducing the overall structure of the edited volume. Chapter 2 explores the contact points of integrated water resource management (IWRM) and social-​ecological systems (SES). The chapter does this by citing water resource management practices by traditional and local resource use systems to argue for a better pathway of urban water ecosystem management by considering humans and water as an integrator for the management of urban water ecosystems. Chapter 3 carries out ecosystem service valuation of the East Kolkata Wetlands, a very important urban wetland in South Asia. The wetland is maintained by traditional knowledge to recycle the urban organic sewage in a specific way so that vegetable farming and pisciculture become possible. The wetland is a Ramsar site because of its unique resource recovery activities and its support to 50,000 people who depend on the wetlands directly and indirectly. The valuation of the ecosystem services (ES), as well as the erosion of these ecosystem services from the wetlands, creates important data for local society and policymakers to assess the socioeconomic loss that the area bears from the loss of the wetland. Chapter 4 deals with the case of possible water scarcity in the peri-​urban agricultural landscape in Tunisia in the face of climate change. This expected future water scarcity and its cascading effects to possible crop failure and loss of livelihoods. The chapter argues for a need for wise use of infrastructure and ecosystem-​based crop cultivation that accepts water scarcity as a new reality. Chapter 5 takes an alternative angle of water ecosystem management by focusing on submarine groundwater discharge, a relatively less discussed topic in sustainable water resource management, including in urban areas. The chapter emphasizes the requirement for interdisciplinary approaches to gain a better understanding of the role of submarine groundwater in coastal ecosystems. Chapter 6 discusses the contact points of water scarcity, resource imbalance, and human mobility, based on a narrative review of the literature. The Chapter argues -​ taking instances from Africa and Asia -​that climatic change-​related shocks such as land degradation and droughts together with water shortage can lead to a reduction

Urban water resource to ecosystem management  7 of household assets, jeopardizing the adaptive capacity of the households, and this may lead to forced migration. Chapter 7 brings the issue of Malawi’s water sector to describe the governance challenges for sustainable urban water supply in the Capital, Lilongwe. Malawi is not a water-​stressed country; however, with the present management system of freshwater resources, there are serious concerns over the continued supply of safe water and the possible increase of water stress in the capital. The chapter argues for better integration of four cross-​cutting issues of gender, research, stakeholder engagement, and capacity building to engage the public with the water ecosystem more to retard possible future water scarcity. The chapter provides a platform to understand the level of integration immediately needed for urban water management in Malawi. Chapter 8 discusses the problem of human health risks due to water stress in the city of Lucknow, India by bringing an indicator-​based approach to assess urban water stress that is often found along with modifications of urban environmental conditions with poor street network, improper solid waste disposal, and inaccessibility to healthcare systems among others. The chapter continues to argue for applying more ecosystem-​based ‘best practices’ with examples around the world as possible mitigation strategies for reducing city-​wide human health risks from water stress. Chapter 9 brings the case of learning points from two river basins in Japan, the Kuma and Yahagi, to argue for a mode of urbanization that is more sustainable and ecosystem-​friendly. Both of these river basins show remarkable alteration and degradation during the post-​Second World War economic growth of Japan, relating to loss of riverine biodiversity and pollution. However, at the same time, they also show remarkable fightbacks in the subsequent years from the basin society. These fightbacks in the form of citizen protests and bottom-​up citizen’s movements have been examples of a more ecosystem-​based river basin stewardship in Japan. Chapter 10 brings the case of ecosystem-​based adaptation to increase resilience in urban water infrastructure in Ca Mau City, Vietnam. Improving the resilience of urban water infrastructure through absorbing and retaining both rain and flood waters in natural lowlands and artificial reservoirs, combined with ecosystem-​based adaptation solutions is stressed as a possible immediate solution for increasing the capacity of urban areas against extreme weather events such as floods and droughts that can affect Ca Mau city in the face of changing climate. Chapter 11 shows the effect of urban forest restoration with both indigenous and exotic species in Karura Forest Reserve, located in the northern central part of Nairobi City. The case represents a real-​world hybrid type of restoration practice for a bundle of ecosystem services acquired from such landscapes. In the Karura forest, not only indigenous species but also exotic species are prioritized as these have significant economic returns, which also poses some uncertainty for long-​ term future ecosystem services. The chapter argues that it is required to properly maintain ecosystem services based on the appropriate knowledge from within the society and to carry out vegetation management that can coexist with both indigenous and exotic elements.

8  Urban Water Ecosystems in Africa and Asia Chapter 12 focuses on the case of hegemonic societal values embodied in the contemporary relationship between water management and landscape in China. The chapter concentrates on the greater bay area in China through assessment of over 130 policy datasets and over 13,000 newspaper articles to argue for a change in river ecosystem management. Chapter 13 discusses the case of information failure as a major cause of the lack of understanding of sustainable water resource management and policy failures across water landscapes. The examines this issue in two levels. The first level examines a technology-​financing solution as a policy intervention and the information failure within that intervention in Kenya. In the second level, the chapter analyses other policy interventions that are related to the technology-​ financing solution to identify other failures across the broader water accessibility landscape. Chapter 14 presents the case of urban flood hazards in Dhaka, Bangladesh, by looking at key policy gaps in flood management in the city. The chapter argues for a transformative change using the stormwater drainage systems more holistically, which includes natural water retention basins and controlling their unplanned encroachments as a major shift needed for Dhaka city. Finally, in Chapter 15, the editors conclude the book by highlighting the main arguments and key takeaways, with an added focus on the future of urban water ecosystem management in Asia and Africa for more effective water governance and policymaking in this region. References Assefa, W. W., Eneyew, B. G., & Wondie, A. (2021). The impacts of land-​use and land-​ cover change on wetland ecosystem service values in periurban and urban area of Bahir Dar City, Upper Blue Nile Basin, Northwestern Ethiopia. Ecological Processes, 10(1), 3. Berkessa, Y. W., Bulto, T. W., Moisa, M. B., Gurmessa, M. M., Werku, B. C., Juta, G. Y., ... & Gemeda, D. O. (2023). Impacts of urban land use and land cover change on wetland dynamics in Jimma city, southwestern Ethiopia. Journal of Water and Climate Change, 14(7), 2397–​2415. Boone, J. K., & Bhomia, R. K. (2017). Ecosystem carbon stocks of mangroves across broad environmental gradients in West-​Central Africa: Global and regional comparisons. PLoS ONE, 12, e0187749. Cheng, Y., Kang, Q., Liu, K., Cui, P., Zhao, K., Li, J., & Ni, Q. (2023). Impact of urbanization on ecosystem service value from the perspective of spatio-​temporal heterogeneity: A case study from the Yellow River Basin. Land, 12(7), 1301. Cheng, Y., Kang, Q., Liu, K., Cui, P., Zhao, K., Li, J., & Ni, Q. (2023). Impact of urbanization on ecosystem service value from the perspective of spatio-​temporal heterogeneity: A case study from the Yellow River Basin. Land, 12(7), 1301. Costanza, R., d’Arge, R., de Groot, R. et al. (1997). The value of the world’s ecosystem services and natural capital. Nature, 387, 253–​260. DCM. (2007). Wetlands: Their Functions and Values in Coastal North Carolina. Morehead City: DCM Printers. Erlich, P. (1978). The Population Bomb. New York: Ballantine.

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10  Urban Water Ecosystems in Africa and Asia UNDP. (2022). Smart Sustainable and Resilient Cities. The Power of Nature Based Solutions: A working paper for the G20. Retrieved on November 12, 2022 from www.wed​ocs.unep.org/​bitstr​eam/​han​dle/​20.500.11822/​36586/​SSRC.pdf?seque​nce=​ 1&isAllo​wed=​y UNEP. (2024). Ecosystem-​ based Adaptation. Retrieved from UNEP Climate Adaptation: www.unep.org/​expl​ore-​top​ics/​clim​ate-​act​ion/​what-​we-​do/​clim​ate-​ada​ptat​ ion/​ecosys​tem-​based-​ada​ptat​ion United Nations, Department of Economic and Social Affairs, Population Division. (2014). World Urbanization Prospects: The 2014 Revision, Highlights (ST/​ESA/​SER.A/​352). Retrieved from: www.pop​ulat​ion.un.org/​wup/​publi​cati​ons/​files/​wup2​014-​hig​hlig​hts.pdf United Nations. (2019). World urbanization prospects 2018: Highlights (ST/​ESA/​SER.A/​ 421). Department of Economic and Social Affairs, Population Division. Wang, Y. P., & Kintrea, K. (2021). Urban expansion and land use changes in Asia and Africa. Environment and Urbanization ASIA, 12(1_​suppl), S13–​S17. https://​doi.org/​10.1177/​ 09754​2532​1999​081 WWF. (2020). Urban Nature based Solutions. Retrieved December 1, 2022 from www.wwf. panda.org/​proje​cts/​one_​pl​anet​_​cit​ies/​wha​t_​we​_​do/​urba​n_​na​ture​base​d_​so​luti​ons/​ Yang, Y., Dou, Y., Wang, B., Xue, Z., Wang, Y., An, S., & Chang, S. X. (2022a). Deciphering factors driving soil microbial life-​history strategies in restored grasslands. iMeta. https://​ doi.org/​10.1002/​imt2.66 Yin, L., Wang, L., Keim, B. D., Konsoer, K., & Zheng, W. (2022a). Wavelet analysis of dam injection and discharge in Three Gorges Dam and reservoir with precipitation and river discharge. Water, 14(4), 567. https://​doi.org/​10.3390/​w14040​567

2 Integrated resource use management practices for better urban water management through the application of SES lens Shamik Chakraborty, Gowhar Meraj, Geetha Mohan, Pankaj Kumar, Amit Chatterjee, and Shib Sankar Bagdi Urbanization is a key factor of global environmental change with key trends that are concerning for the sustainability debate in general; these changes are that the spatial extents to urban areas are increasing more than their population, urban areas modify their climate and rainfall, they consume vital ecosystems including agricultural land, they pressurize biodiversity hotspots. In the future, urban areas will develop in areas of limited resources, further pressurizing biodiversity and ecosystem services (Seto et al., 2013). Urbanization is a process that grew exponentially with a slow start. In the year 1800 for example, only about 3% of the population of the world was living in cities, and in the year 1900, only about 10% of the world’s population lived in cities (Davis, 1955), and by 1950, about 30% of the world’s population lived in cities (UN, 2010). The rate of urban growth is high in the developing world in the global south. The 1950s was the start of the high level of industrialization and urbanization, referred to as ‘the great acceleration’, which started to see deterioration and overexploitation of vital and highly interlinked life support functions of the earth-​atmosphere system. Some indicators that denote this deterioration are an exponential increase in the population, water use, atmospheric CO2 concentration, species extinction rate, frequency of natural disasters such as floods, degradation of the terrestrial biosphere, and tropical forest loss, among others (Steffen et al., 2004). This rate of acceleration of deterioration was never seen in the history of humanity, leading to globally recognized human-​induced changes for the first time in Earth’s history. A scientific observation and argument that led to the name of the present epoch as the ‘Anthropocene’. The Anthropocene has seen adverse changes in the earth’s natural resource systems. Water, among these, is a critical and indispensable natural resource and is vital for the health of every species, a nation’s socio-​economic well-​being, and environmental equilibrium. Despite Earth’s water-​covered surface, global access to water supply remains a complex challenge, with projections indicating that three billion people will face water scarcity by 2025 (Khanai et al., 2020; Hanjra & Qureshi, 2010). Amidst these challenges, the adoption of effective water management systems emerges as a critical imperative. DOI: 10.4324/9781003437833-2

12  Urban Water Ecosystems in Africa and Asia One approach is a possible holistic application of water resource management practices. In this sense, the term Integrated water resource management or IWRM has been a debatable topic in the academia and policy-​making arena due to mainly the limited scope of the keyword ‘integrated’ applied through the concept and its practice. Despite having a long history of IWRM, scholars have argued that IWRM lacks a holistic perspective (Saravanan, 2006). The IWRM concept has evolved through different schools of thought, which include the importance of formal or informal mechanisms to implement IWRM; while still others argue for a blend of both (formal and informal mechanisms) for a successful implementation of IWRM (Saravanan, 2006). One vital aspect that remains largely unprobed is the connection of the water ecosystem based on which the whole concept and its implementation revolve. This gap with lesser ecosystem-​based IWRM can be a vital link behind the successful implementation of IWRM (Chakraborty, 2010). 2.2  The disconnect between IWRM and ecosystems: A key to failure Integrated Water Resources Management (IWRM) seeks to manage water sustainably and fairly. Yet, in practice, it often struggles to fully achieve these goals. One key issue is its insufficient integration with water ecosystems. This section explores the ramifications of this gap, drawing on scientific analysis and case studies. IWRM intends to manage water by accounting for the entire water cycle and intertwining social, economic, and environmental factors. However, many IWRM applications fall short in effectively including ecological aspects (hereafter referred as non-​ecological WRM). This results in disjointed and occasionally detrimental approaches to water management. The Aral Sea crisis is a notable example of environmental mismanagement (Small and Bunce, 2003). In Central Asia, particularly in Kazakhstan and Uzbekistan, intensive cotton farming requires extensive irrigation (White, 2013). This led to the diversion of water from the Aral Sea’s tributaries (Spoor, 1998) without regard for the ecological consequences. The result was one of the most severe environmental disasters globally, with the lake shrinking dramatically (Loodin, 2020). This change caused an ecological collapse, altered the local climate (Su et al., 2021), and created serious health issues for nearby communities due to toxic dust (Indoitu et al., 2015) from the exposed lakebed This crisis highlights the importance of an ecosystem approach in water management based on key ecological principles like connectivity, resilience, adaptability, biodiversity, and ecosystem services. Water ecosystems are interconnected; changes in one part can significantly impact other areas (Falkenmark, 2003). Non-​ecological WRM often fails to recognize this, treating projects like dam construction or water diversion as isolated events rather than parts of a larger system. Healthy ecosystems can usually withstand environmental stressors (Equihua et al., 2020), but overexploitation and pollution can diminish this resilience (Hossain, 2019), making them more vulnerable to climate change and other stressors (Nellemann and Hain, 2008; Gutiérrez et al., 2016). Additionally, biodiversity is essential for sustaining ecosystem services such as water purification, flood control, and habitat provision. Non-​ecological

Integrated resource use management practices  13 WRM practices can threaten this biodiversity, undermining these crucial services (Murphy et al., 2021; Yan et al., 2022). Building on the example of the Aral Sea, the Florida Everglades restoration offers a contrasting case study where an ecosystem-​based WRM approach was successful (Cook et al., 2014; Smith et al., 2020). Unlike the Aral Sea, where development disregarded ecological balance, the restoration of the Florida Everglades involved efforts to reinstate the wetland’s natural water flow (Sullivan et al., 2014). This restoration, guided by ecological principles, aimed to maintain the region’s biodiversity and enhance its resilience against climate change. Such efforts underscore the importance of considering natural hydrological patterns in ecosystem management. Exploring further into the consequences of non-​ecological WRM practices, two critical issues emerge: overexploitation and pollution and the challenge to water security and environmental sustainability. In the Punjab region of India, for example, agricultural practices heavily reliant on groundwater extraction have led to a drastic decrease in water table levels (Gautam et al., 2020; Sidhu et al., 2021). Furthermore, the excessive use of fertilizers contributed to water pollution (Singh and Craswell, 2021; Zahoor and Mushtaq, 2023), exemplifying the complex interplay between human activity and environmental health. Similarly, in the Mekong River Basin, which is vital for Southeast Asia’s ecological and economic well-​ being, the construction of dams represents a significant non-​ecological WRM practice (Webb and Iskandarani, 1998; Fernandino et al., 2018). These dams disrupt the natural flood-​drought cycles, crucial for local fisheries, agriculture, and sediment transport (Cosslett et al., 2018; Hoeferlin, 2020; Gunawardana et al., 2021). This disruption not only affects the immediate environment but also poses long-​term risks to the region’s ecological balance and sustainability (Pokhrel et al., 2018; Hecht et al., 2019). These cases collectively highlight the need for an integrated, ecosystem-​focused approach in WRM, considering the interconnectedness and complexity of natural water systems. Drawing from these lessons, it becomes evident that for Integrated Water Resource Management (IWRM) to be effective, it must fundamentally align with ecological principles. This alignment requires a deep understanding of natural water cycles, the functions of ecosystems, and the intricate link between water management and the broader context of environmental sustainability. By incorporating these principles, IWRM can evolve into a practice that not only meets human water needs but also preserves and enhances ecological health. Such an approach paves the way for a more sustainable, resilient, and equitable framework in managing water resources, ensuring that both human and environmental needs are addressed in a balanced and informed manner. 2.3  Indigenous/​traditional and local knowledge-​based ecosystem management as a possible way to connect IWRM to SES One possible way to reconnect with (water) ecosystems can be through human-​ managed water harvesting and restoration practices that are resilient and time-​ tested. Indigenous /​traditional knowledge systems, in this sense, have gained

14  Urban Water Ecosystems in Africa and Asia significance. World Bank has expressed IK/​TLK as ‘the missing link between neglect and empowerment, as well as between losing and surviving’ (World Bank 1999). These ecosystems where humans and nature are interlinked and closely interacting are considered as social-​ecological systems (SES) (see Berkes et al., 2003, Leslie et al., 2015). IK /​TLK’s contribution to the management of water ecosystems has been a central argument in water conservation and sustainable harvesting (Everard, 2020). The Convention of Biological Diversity asks to ‘respect, preserve, and maintain knowledge, innovations and practices of indigenous and local communities... and encourage equitable sharing of the benefits’ (CBD: Article 8j), which links closely to the statement in Article 10, a: ‘integrate consideration of the conservation and sustainable use of biological resources in national decision-​making’ (CBD, 2010: Article 10a). The most recent policy platform in IK/​TLK-​IPBES -​refers this this knowledge as indigenous and local knowledge or ILK, where diverse worldviews and a better integration of IK/​TLK have been stressed for effective conservation of biodiversity and ecosystems (Diaz et al., 2015). This knowledge can be manifested in many ways; such as through beliefs, rituals, observation, and folklore among others (Singh et al., 2023). These are handed down through generations for continuous maintenance and use. Low cost for making and maintenance, as well as the simplicity of operation makes the IK/​TLK based water management systems operatable without any external support. These low-​ key methods also primarily support subsistence farming rather than cash crop farming (FAO, 2001); thus, converging on the vital issue of long-​term poverty reduction and maintenance of diversity and well-​being, adding resilience for a region under changing climate (for example, through cultivation of climate resilient crops) and socioeconomic situations (for example, to be able to know how to produce, forage and share food beyond market-​based interactions) (Boehm et al., 2023). However, this knowledge system has been under constant threat. For example, Ecosystems and livelihoods can both deteriorate due to abandonment due to government policies (Haque, 2022) coastal areas for raising income (see Siddique et al., 2023), as well as displacement of indigenous and local communities due to unsustainable land use practices near urban areas (see Jerez, 2021). These unsustainable practices can reduce cultural components that interact with direct interactions with nature, which is a vital attribute for maintaining the IK/​TLK based water management (IPBES, Diaz et al., 2015). Below we provide two examples of how IK/​TLK in water management systems may work in real urban /​peri-​urban settings: An increasingly recognized and time-​tested solution to alleviate pressure on overexploited groundwater has become crucial in meeting diverse water needs, from drinking and sanitation to irrigation, particularly in regions like Asia (India and China) and various African countries (Richards et al., 2021). Rooted in traditional conservation practices, rainwater harvesting (RH) has experienced a revival with recent technological developments. While advancements in water harvesting techniques hold promise, challenges persist in the implementation of such advanced technologies. The significance of traditional water harvesting technologies is

Integrated resource use management practices  15 explored, considering their potential to address the complex interplay of climate change, population growth, and hydrological uncertainties (Rahaman et al., 2019; Quon et al., 2023). In response, rainwater harvesting (RWH) emerges as a pragmatic solution, offering advantages for individuals, governments, and the environment. An engrained in ancient practices, RWH is experiencing renewed interest due to escalating water demand, prompting active promotion by institutions in both urban and rural settings. Embracing principles of harvesting, conservation, and reuse, RWH presents a sustainable approach to augmenting water availability amid rising demand, especially in urban areas (Krishan, S., 2011; Yannopoulos et al., 2017). The experiences of countries like India and challenges in African communities emphasize the need to blend traditional wisdom with modern innovations for a sustainable water future, as intensifying water scarcity is causing deteriorating sources and critical drought conditions. India is currently facing substantial reservoir depletion, underscoring the urgency of addressing this challenge. The country’s rich tradition of water harvesting reflects ingenious practices, such as rainwater harvesting in the Thar Desert and unique systems like Nahri in Madhya Pradesh (Krishan, S., 2011). These practices contribute to water conservation and help fulfill SDG target 6.5, creating an environment that supports technologies and aligns with the imperative of securing sustainable integrated resource water management practices in water-​scarce countries. Reconnecting with water ecosystems with IK/​TLK-​based management in urban areas can lead to more endogenous development. For example, cities in Africa are expected to grow fast with approximately 1.5 billion people possibly inhabiting its cities. This will happen with limited infrastructure and funding to cover the costs of infrastructure development (van den Berg and Fikresilassie, 2023). The communal nature and low maintenance cost and operations of IK/​TLK-​based water ecosystem management can meet this challenge of unplanned urbanizations looming over Africa, especially and to a lesser extent in Asia. In addition to the development of human-​made infrastructure such as traditional rainwater harvesting structures mentioned above, this kind of water ecosystem management can also take place through the capacity-​building of the TLK holders to conserve and maintain intact/​ degraded natural ecosystems. For example, the peri-​urban mangrove areas in Kenya were rich ecosystems delivering, food, fiber, and fuel to local communities in and near Nairobi. However, these peri-​urban mangroves have been damaged by mainly anthropogenic pressures (Mohamed, 2009). As a result, Kenya has seen the degradation of half of its original mangrove cover in last 50 years. These mangroves provided multiple direct benefits to the peri-​urban society including food, medicines, fuel, and timber, as well as indirect benefits such as shoreland erosion prevention, carbon sequestration, and habitat provision among others. Recently, communities with their local ecological knowledge are coming forward and engaging together to restore these mangroves, not only to re-​establish direct benefits but also as an ecosystem to open the possibilities of a plethora of benefits available from intact mangroves. Seeking multiple benefits from coastal ecosystem is a potential solution for achieving

16  Urban Water Ecosystems in Africa and Asia sustainable use and conservation of coastal ecosystems (Chakraborty et al., 2020, Chakraborty et al., 2023); including mangroves of peri-​urban Mombasa (Mohamed et al., 2009). Without the active involvement of the locals who strive to internally boost their capacity to understand mangroves better, it would not be possible for either internal or external organizations to achieve the restoration of Kenya’s mangroves in the long term. For example, fishers mentioned that initially, they preferred to have fish farms in the mangroves but after learning about the mangrove’s role in coastal fisheries they started thinking more about the health of the mangroves for the overall health of the fisheries in the area. This is a behavioral change possible and needed for the successful implementation of IK/​TLK-​based water ecosystem management near urban areas. This is because IK/​TLK may sometimes be alienated and degraded (to start with) in urban and peri-​urban areas. Therefore, the right type of intervention may need the development of the capacity of the locals to understand and then work for the ecosystem to create a win-​win situation rather than work under donations, or external investments (as often happens for commercial shrimp farming), thereby possibly increasing long term debts in the area (Nguyen and Ford, 2010) (a win-​loss situation). 2.4 Conclusion Integrated water resource management or IWRM can be a powerful concept but not applied to its potential to ‘integrate’ water resource management for both conservation and sustainable use of this vital resource. The Aral Sea case shows that IWRM as a result can fall short in effectively including ecological aspects, which can result in detrimental effects on water ecosystem management. It is in this sense that efforts should be made to possibly integrate robustly a management aspect that depends on conservation and sustainable use such as water management systems based on IK/​TLK such as through rainwater harvesting and conserving vital water ecosystems near urban areas. The case of ecosystem management mangrove systems of peri-​urban Mombasa with local involvements is an example that shows that it is possible to conserve and wisely manage urban and peri-​urban mangrove ecosystems. The urban mangroves can then provide multiple benefits to society such as food, fiber, recreation, and health, as well as carbon sequestration, habitat provision, prevention of soil erosion, and protection of the coastal areas from storm surges. This is an example of water resource management of an integrated nature that takes the whole ecosystem into consideration. Second, the case also shows that behavioral change in society is also possible to aid such holistic conservation of urban water ecosystems.

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Integrated resource use management practices  17

Figure 2.1 Location of the peri-​urban mangrove area near Mombasa, Kenya.

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20  Urban Water Ecosystems in Africa and Asia Nguyen, T. T., & Ford, A. (2010). Learning from the neighbors: economic and environmental impacts from intensive shrimp farming in the Mekong Delta of Vietnam. Sustainability, 2(7), 2144–2162. Pokhrel, Y., Burbano, M., Roush, J., Kang, H., Sridhar, V., & Hyndman, D. W. (2018, March 3). A review of the integrated effects of changing climate, land use, and dams on Mekong river hydrology. Water, 10(3), 266. Quon, H., & Jiang, S. (2023). Decision making for implementing non-​traditional water sources: A review of challenges and potential solutions. npj Clean Water, 6(1), 56 Rahaman, M. F., Jahan, C. S., & Mazumder, Q. H. (2019). Rainwater harvesting: Practiced potential for integrated water resource management in drought-​ prone Barind tract, Bangladesh. Groundwater for Sustainable Development, 9, 100267. Richards, S., Rao, L., Connelly, S., Raj, A., Raveendran, L., Shirin, S., ... & Helliwell, R. (2021). Sustainable water resources through harvesting rainwater and the effectiveness of a low-​cost water treatment. Journal of Environmental Management, 286, 112223. Saravanan, V. S. (2006). Integrated water resource management: A response. Economic and Political Weekly 41(38): 4086–​4087. Seto, K. C., Parnell, S., & Elmqvist, T. (2013). A Global Outlook on Urbanization. In T. Elmqvist, et al (Eds). Urbanization, Biodiversity and Ecosystem Services: Challenges and Opportunities. Springer. Siddique, M. R. H., Hossain, M., & Rashid, A. M. (2023). The dilemma of prioritizing conservation over livelihoods: Assessing the impact of fishing restriction to the fishermen of the Sundarbans. Trees, Forests and People, 11, 100366. Sidhu, B. S., Sharda, R., & Singh, S. (2021). Spatio-​temporal assessment of groundwater depletion in Punjab, India. Groundwater for Sustainable Development, 12, 100498. Singh, B. & Craswell, E. (2021). Fertilizers and nitrate pollution of surface and ground water: an increasingly pervasive global problem. SN Applied Sciences 3, 518. https://​doi. org/​10.1007/​s42​452-​021-​04521-​8 Singh, H. B., Yaipharembi, N., Huidrom, E., & Devi, C. A. (2023). Traditional Knowledge, Beliefs, and Practices Associated with Ethnic People of Manipur, North East India in Conservation of Biodiversity. In Traditional Ecological Knowledge of Resource Management in Asia (pp. 61–​75). Cham: Springer International Publishing Small, I., & Bunce, N. (2003). The Aral Sea disaster and the disaster of international assistance. Journal of International Affairs, 56(2), 59. Smith, M., Chagaris, D., Paperno, R., & Markwith, S. (2020). Ecosystem structure and resilience of the Florida Bay Estuary: An original ecosystem model with implications for everglades restoration. Marine and Freshwater Research, 72(4), 563–​583. Spoor, M. (1998). The Aral Sea basin crisis: Transition and environment in former soviet Central Asia. Development and Change, 29(3), 409–​435. Steffen, W. (2004). Global change and the earth system: A planet under pressure. Springer Su, Y., Li, X., Feng, M., Nian, Y., Huang, L., Xie, T., Zhang, K., Chen, F., Huang, W., Chen, J., & Chen, F., 2021. High agricultural water consumption led to the continued shrinkage of the Aral Sea during 1992–​2015. Science of The Total Environment, 777, 145993. Sullivan, P. L., Gaiser, E. E., Surratt, D., Rudnick, D. T., Davis, S. E., & Sklar, F. H. (2014). Wetland ecosystem response to hydrologic restoration and management: The Everglades and its urban-​agricultural boundary (FL, USA). Wetlands, 34, 1–​8. United Nations. (2010b). World urbanization prospects: The 2009 revisions. New York: Department of Economic and Social Affairs.

Integrated resource use management practices  21 van den Berg, R., & Fikresilassie, F. (2023). As Cities Grow Across Africa, They Must Plan for Water Security. World Resources Institute. Retrieved on April 12, 2024 from www. wri.org/​insig​hts/​cit​ies-​grow-​acr​oss-​afr​ica-​they-​must-​plan-​water-​secur​ity Webb, P., & Iskandarani, M., 1998. Water insecurity and the poor: Issues and research needs. ZEF–​Discussion Papers On Development Policy, (2). Available at SSRN: https://​ssrn. com/​abstr​act=​3316​741 or http://​dx.doi.org/​10.2139/​ssrn.3316​741 White, K. D. (2013). Nature–​society linkages in the Aral Sea region. Journal of Eurasian Studies, 4(1), 18–​33. Yan, X., Li, X., Liu, C., Li, J., & Zhong, J. (2022). Scales and historical evolution: Methods to reveal the relationships between ecosystem service bundles and socio-​ ecological drivers—​A case study of Dalian City, China. International Journal of Environmental Research and Public Health, 19(18), 11766. Yannopoulos, S., Antoniou, G., Kaiafa-​ Saropoulou, M., & Angelakis, A. N. (2017). Historical development of rainwater harvesting and use in Hellas: A preliminary review. Water Science and Technology: Water Supply, 17(4), 1022–​1034. Zahoor, I., & Mushtaq, A. (2023). Water pollution from agricultural activities: A critical global review. International Journal of Chemical and Biochemical Sciences, 23, 164–​176.

3 Ecosystem service valuation and risk assessment of a Ramsar site region (India) for strengthening protection and conservation Soumik Saha, Biswajit Bera, Pravat Kumar Shit, Sumana Bhattacharjee, Nairita Sengupta, Debashish Sengupta, and Partha Pratim Adhikary

3.1 Introduction Urbanization is the primary factor for the rapid depletion and scarcity of natural resources from natural capital. The undesirable spillover effects of unscientific urbanization over the ecosystem and environment are uninterruptedly indicated as a matter of concern for the government, environmentalists, and urban planners (Mondal et al. 2017). Wetlands are documented as environmentally friendly natural resources, and it is also an integrated and complex ecosystem that provides various ecosystem services (Guirguis 2004). Wetlands are the transitional zone between aquatic and terrestrial ecosystems, and the level of the ground water table is mostly situated near the ground surface (Mitsch and Gosselink 2007). Ecosystem Services (ES) signify the combination of services and goods from a natural environment or ecosystem that is very much essential for human well-​being (Costanza et al. 1997; Li et al. 2014). Ecosystem service valuation is an approach that significantly employs market values to the environmental functions or services. Wetlands provide a branch of ecosystem services, including flood control, fisheries, recycling of organic waste, cultural and spiritual services, recharge of groundwater, and habitat for various plants and animals, and they also give an aesthetic service to the people (Jia et al. 2011; Hopkinson et al. 1997).Wetland ecosystem (including lakes, rivers, coastal wetlands, rice fields, etc.) provides different ecosystem services that contribute to poverty alleviation, economic development and human well-​being (Bera et al. 2021a; Bera et al. 2022a). The two most recognized provisional wetlands ecosystem services are fish (including food material) and drinking water supply. According to the National Wetland Atlas, in India, 15.26 million ha area was under wetland class in 2005. Inland wetlands contribute 10.56 million ha (69.22%) area and these wetlands have a particular importance as it is the primary sources of animal protein (MEA 2005). The EKW region is a dynamic and multifaceted system that provides a wide range of materials, goods, and services to the native DOI: 10.4324/9781003437833-3

Ecosystem service valuation and risk assessment of a Ramsar site  23 people in several ways (generating direct employment situation to the people through providing fish, vegetables, weeding etc. It mitigates environment degradation and reduces aquatic health hazard) (Kundu and Chakraborty 2017). Presently, the EKW region is producing 15000 metric tons (MT) of fish per year through 264 ponds (locally called bheries). Additionally, this area can produce 150 tons of cultivable vegetable products daily, and it is considered the backbone of the food security of the Kolkata megacity (Kundu and Chakraborty 2017). The wetland ecosystem can support millions of people not only who are residing in the peripheral region of wetlands but also the people who are inhabiting far away from the wetlands through various goods and services. The wetlands around the world occupy 6.5% of the Earth’s surface area but contribute 14.7% to ecosystem service values (Costanza et al. 1997). The conversion of wetlands into residential areas is occurring in different parts of the world due to rapid rural and urban population growth and the execution of various anthropogenic developmental activities (particularly the wetlands, which are adjacent to the metropolitan areas) (Maltby et al. 2006). The speedy urban expansion or urban sprawl is the principal cause of the reduction of wetland areas, particularly in developing countries like India. Indian megacities dramatically capture the wetlands that are located in the proximity of a city or town. Mangrove areas closer proximity to the Mumbai megacity, lakes near the Navi Mumbai area, and East Kolkata Wetlands (eastern fringe area of the Kolkata metropolitan area) are significant examples of wetland shrinkage and negative consequences of urbanization (Ghosh and Das 2019; Mondal et al. 2017). Other important wetland conversion areas in Southeast Asian countries are the Colombo Flood Detention Area, Attidiya Marsh (Colombo, Sri Lanka), Ramna Lake, Gulshan Lake, and Ashulia wetlands (Dhaka, Bangladesh). The exponential growth of population, intensive growth of urban areas, economic reforms, and increase of industries and real estate market are the responsible factors behind wetland depletion (Mondal et al. 2017). East Kolkata Wetland (EKW), previously known as East Calcutta Wetland (EKW)is an integrated natural and manmade wetland that is situated in the eastern part of Kolkata (India) and it is characterized by high biological diversity (total of 104 various plant species, 40 bird species that also include various migratory birds, around 20 mammalian species and reptiles) (Chaudhuri et al. 2012). EKW region was termed as a ‘Wetland of International Importance’ in the ‘Ramsar Convention’ in August 2002 and selected as a Ramsar site in November 2002. The entire area of EKW (around 125 km2) is characterized by marshes, swamps, Bheries and Jheels (wastewater treatment areas), damping areas, sewage canals, and cultivable lands (Ghosh 1990).West Bengal state government started its developmental activities in the 1950s, and an expansion of the city region toward EKW was adopted to overcome commercial and residential problems within the city (Sengupta 2018). Presently, the escalating rate of vulnerability and degradation of wetlands have become a contemporary environmental issue. Nowadays, remote sensing and geographical information system (RS & GIS) techniques extensively assist to regional planners and administrators for wetland management (Chen et al. 2014). The environmental and ecological modeling of wetland shrinkage is a significant way to identify the vulnerable, risk zones, and

24  Urban Water Ecosystems in Africa and Asia environmental stressors for drastic reduction of wetland areas. Though natural factors have little contribution to wetland shrinkage, sea-​level changes, storms, and droughts greatly influence the wetland depletion process through the progress of time (Nicholls et al. 1999). For the evaluation of the wetland shrinkage status, different traditional overlay models, bivariate, multi-​variate and statistical models are extensively used, which are globally well accepted (Ancog and Ruzol 2015). Conversion of wetland risk modeling is totally dependent on the functional relationship and assumption of exploratory factors or the independent variables. Several numerical and statistical approaches like tree-​based non-​linear model, fuzzy-​ based model (optimization), spectral mixture analysis, different MCDA methods, and process-​based methods are very useful methods that can calculate the spatial stress over wetland ecosystems (Sica et al. 2016; Zeng et al. 2017; Zhang et al. 2011; Mondal et al.2017; Ghosh and Das 2020). It is well established that machine learning models have more accuracy in model-​building studies than bivariate and multi-​variate statistical modeling (Tien Bui et al. 2016). Machine learning studies have been successfully applied to flood susceptibility analysis, landslide susceptibility modeling, groundwater potential mapping, forest fire susceptibility analysis, deforestation susceptibility, etc. (Tehrany et al. 2013; Sharma et al. 2013; Pourghasemi et al. 2017; Das et al. 2022). Different previous studies have tried to analyze the shrinkage or spatial depletion of East Kolkata Wetlands (EKW) with the help of different statistical and machine learning models (ML). It is also identified that around 46% of wetlands (out of 38 sq. km) will turn or alter into different land use classes by 2025 (Mondal et al. 2017). Wetland conversion susceptibility zones have been determined in the EKW region with the help of the SVM (Support Vector Machine) and RF (Random Forest) model, which analyzed that around 60% of areas fall under high and very high susceptibility classes (Ghosh and Das 2020). The primary objectives of this study are (i) to explore the changing pattern of ecosystem service values (ESVs) in the EKW region with the help of different unit values. (ii) to determine the wetland shrinkage susceptibility zones by applying three different machine learning (ML) models (Support Vector Machine (SVM), Naïve Bayes (NB), and K-​nearest neighbor (KNN)). 3.2  Area of study and its hydro-​geomorphic signature East Kolkata Wetlands (Ramsar site) is situated in the eastern fringe of the Kolkata metropolitan which is encircled by 22°25’ N to 22°40’ N latitude and 88°20’ E to 88°35’ E longitude (Figure 3.1). The geographical area of EKW is 12500 hectares, and it includes 32 mouzas under both North and South 24 Parganas districts. Afterward, five mouzas (i.e. Kalikapur under Purva Jadavpur P.S, Dakshin Dhapa Manpur and Kochpukur under Kolkata Leather Complex, Nonadanga under Tiljala P.S in South 24 Parganas and Thakdari under Rajarhat P.S in North 24 Parganas) are incorporated within the territory of EKW region. The whole area of EKW is controlled under the jurisdiction of two municipalities and seven-​gram panchayats. The seven gram panchayats under South 24 Parganas, namely Beonta I, Beonta II, Bamanghata, Tardaha, Kheyadaha I, Kheyadaha II, and Pratapnagar cover the

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Ecosystem service valuation and risk assessment of a Ramsar site  25

Figure 3.1 Geographical location of the study area.

26  Urban Water Ecosystems in Africa and Asia Table 3.1 Plant species diversity and its economic importance of EKW region Scientific name

Parts used

Used as

Centella asiatica (L.) Urban

Leaf

Cyperus rotundus L. Heliotropium indicum L. Enhydra fluctuans Lour.

Tuber Whole plantLeaf-​root Flower Leaf

Eclipta prostrata (L.)

Entire plant

Mouth and throat ulcers, Appetizer, Antidysenteric, Leprosy Use as a cooling agent Skin disease, Fevers, Cough & Fever Laxative, Antibilious, Demulcent, Cutaneous Jaundice, Hair-​tonic, Anti-​ inflammatory, Anthelmintic, Anoxia, Vulneary Antispasmodic, Stomachic, Deobstruent Leprosy, Demulcent, Refrigerent, Laxative, Dropsy Antidote to Scorpion sting Diaphoretic, diuretic, demulcent Jaundice Burns, Itches & Boils

Grangea maderaspatana (L.) Leaf Poiret Commelina benghalensis L. Entire plant Ceratophyllum demersum L. Canna indica L. Aeschynomene aspera L. Commelina diffusa Burm.

Whole plant Root, Rhizome & Scape leaf Root Entire plant

maximum no. of the above-​mentioned mouzas (Chakraborty and Das Gupta 2019). The micro-​organisms and plants (Table 3.1) play a crucial role in wastewater recycling, particularly for internationally significant Ramsar sites. The term ‘East Kolkata Wetlands’ was propounded by Dr. Dhrubajyoti Ghosh in 1983 (Ghosh 1990; Furedyand Ghosh 1984). Actually, this area is a part of the mature Ganga Delta Plain and these wetlands are mainly intertidal marshy land of the Ganga Delta. Since the early phase of the last century, few streams were previously active, but now they have been decayed due to the stop of headwater supply while the rest of the active rivers are engaged to build landmass along both of their flanks. The landmass that emerged in between the elevated zones is relatively lowered due to the shortage of annual siltation (Bagchi 1944). Formerly, this topographic low-​ lying depression was enclosed with saline marshes, which are situated between the river Bidyadhari on the eastern side and river Hooghly on the western side (Ghosh and Sen 1987). These water bodies represent a spill basin of tidal river Bidyadhari, which was divulged into the Bay of Bengal through river Matla (CMG 1924-​25). The central lake channel (a spill canal of Bidyadhari) was stretched through the core part of Kolkata during the first phase of the twentieth century, and it was considered the city's major drainage line (CMG 1929). East Kolkata Wetlands is a biologically delicate region, and it is the world’s biggest area of sewage-​fed fish production (Figure 3.1 and Table 3.2). It supports the sustenance of more than 2000 core groups of people who are producing 15000 tons fish per annum (Ghosh et al. 2018). Previously, the East Kolkata Wetlands region was treated as a buffer area. However, in recent years, this area has been used as a dumping ground for urban

Ecosystem service valuation and risk assessment of a Ramsar site  27 Table 3.2 Status of some important fauna species within EKW region Scientific name Fish Labeo rohita Catla catla Cirrhinus mrigala Oreochromis mossambica Oreochromis nilotica Liza parsia Puntius chila Amblypharyngodon mola Mystus vittatus Channa striatius Mastacembetus panalus Mastacembetus armatus Anabas testudineus Amphibian Rana tigrina Rana limnocharis Rana hexadactyla Reptile Xenochropespiscator Amphiesma stolata Calotes versicolor Hemidatylusflaviviridis Ptyas mucosus Vipera russelli Ahaetula nasutus Varanus flavescens Mammals Herpestes auropunctuatus Pteropus giganteus Pipistrellus coromandra Mus booduga Mus platythrix Herpestes palustris

Native name

Abundance

Rui Catla Marigel Telapia Nilotica Parse Punti Murala Tangra Sol Pankal Ban Koi

Common Common Common Common Common Rare Rare Rare Rare Rare Sporadic Sporadic Sporadic

Bull Frog Cricket Green Frog

Common Common Sporadic

Jal Dhora Helay Girgiti Tiktiki Daras Chandra Bora Laudoga Go Sap

Common Common Common Common Sporadic Rare Sporadic Sporadic

Beji Badur Chamchika Metho Indur Nangti Indur Marsh Mongoose

Common Common Common Common Common Rare

sewage and solid waste materials. Sewage drains run through the fishing ponds, which encompass a geographical area of 4000 hectares, and these wetlands allow an extensive array of physicochemical and biotic elements for refining the water quality (Kundu et al. 2008). 3.3  Dataset and methodology 3.3.1  Data sets & land use land cover (LULC) classification

Land use land cover (LULC) classification and its transformation analysis (Figure 3.2) is a significant part of ecosystem service valuation and model building study. It can

28  Urban Water Ecosystems in Africa and Asia Table 3.3 Multiple wetland ecosystem services provide from EKW region Wetland ecosystem services Provisional services Fiber and fuel Fresh water Food Genetic materials Supporting services Nutrient cycling Formation of soil Regulatory services Natural hazard regulation Climatic regulation Water regulation Water purification Erosion regulation Cultural services Recreational services Aesthetic services Spiritual services

Benefits to the people Production of logs, fuelwood and fodder Use in domestic and drinking purposes Fish, grains, fruits production Different ornamental species, resistance to plant pathogen Helps in processing, storage and recycling of nutrients Helps in different types of soil formation by sediment retention and various organic matter accumulation Natural flood control, urban flood control Act as a carbon sinker, helps in maintaining temperature in a local or regional scale Helps in ground water recharge, purification and discharge Purify the wastewater and remove nutrients and other pollutants from water Decrease the rate of soil erosion Act as a recreational place Wetlands provide an aesthetic value to the people Many religious and spiritual rituals are concentrated to the wetlands

explicitly demonstrate the dynamic pattern of ESVs over a particular region. In this scientific study total of three LULC maps have been generated (for 1975, 2000, and 2021) (Figure 3.2). Various Landsat imageries such as Multi-​Spectral Scanner (path/​row is 148/​44), Thematic Mapper (path/​row is 138/​44) and Operational Land Imageries (path/​row is 138/​44) have been used to categorize the entire EKW region into different LULC types or different eco-​units (such as vegetation/​sparse forest, settlement/​build-​up lands, bare land/​fallow land, waterbody and cropland/​agricultural fields). Satellite images are downloaded from the USGS (United States Geological Survey) website (https://​earthe​xplo​rer.usgs.gov/​). In this scientific study, a maximum likelihood classifier has been used for land use land cover categorization. Haze reduction & Atmospheric correction have also been done through Eardas Imagine software during the image pre-​processing period. Here, a specific year gap (1975, 2000, and 2021) has been selected that can allow the researchers to observe and analyze the long-​term changing trends of the wetland ecosystem. This kind of long-​term gap can be considered for policymaking and management. 3.3.2  Computation of ecosystem service values (ESVs)

To determine the evident ecosystem service values (ESVs) of various eco-​units in the East Kolkata Wetland (EKW) region, several valuation methods or unit values

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Ecosystem service valuation and risk assessment of a Ramsar site  29

Figure 3.2 LULC map of the referenced years (1975, 2000 and 2021) along with LULC change statistics for the consecutive years.

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LULC classes 1975 Wetland Vegetation Open land Agricultural land Settlement

%

2000

%

2021

%

1975–​2000 % of change 2000–​2021 % of change 1975–​2021 % of change

4401.00 35.12 3089.00 24.65 2360.00 18.83 -​1312.00 2341.00 18.68 2329.00 18.59 2719.00 21.70 -​12.00 349.00 2.79 1013.00 8.08 250.00 2.00 664.00 5173.00 41.28 5510.00 43.97 6283.00 50.14 337.00 266.00

2.12

589.00

4.70

918.00

7.33

323.00

-​29.81 -​0.51 190.26 6.51

-​729.00 390.00 -​763.00 773.00

-​23.60 16.75 -​75.32 14.03

-​2041.00 378.00 -​99.00 1110.00

-​46.38 16.15 -​28.37 21.46

121.43

329.00

55.86

652.00

245.11

30  Urban Water Ecosystems in Africa and Asia

Table 3.4 Transformation of land use land cover in EKW region within the research period (1975–​2021)

Ecosystem service valuation and risk assessment of a Ramsar site  31 Table 3.5 Ecosystem service values (ESVs) in per unit area (ha) of different unit values or value LULC classes

Wetland Settlement Cropland Forest land Bare land

Costanza et al., (1997)

Costanza et al., (2014)

De Groot et al., (2012)

Xie et al., (2008)

C97a

C97b

C11

D12

X8

14785 0 92 232 0

20404 0 126 321 0

140174 6661 5567 4166 0

25682 0 5567 2871 0

10118.078 0 1459.43 2155.888 0

Coefficient for EKW region

such as Costanza et al. 1997, Costanza et al. 2014 (C97a, C97b, C11), De Groot et al. 2012 (D12), Xie et al. 2008 (X8) have been applied as a value coefficient (Table 3.5). The identified land use land cover classification maps of the selective years (1975, 2000, and 2020) have been used as a proxy for explicit estimation of ecosystem service valuation (ESVs) of the referenced LULC classes (Figure 3.3). The value coefficients (VC) are assigned with the help of the above-​mentioned methods to every eco-​unit or LULC class and multiplied by the area (ha) of the representative LULC class (Figure 3.3). The aggregation ESVs of all classes are represented as total ecosystem service value (TESV). It follows, ESVi = ( Ak *VCk ) (3.1) ESVt = £ ( Ak *VCk ) (3.2) Here, ESVi & ESVt indicate the ecosystem service values (ESVs) of individual and total LULC classes, respectively. A Signifies area in hectares and VC represents value coefficient (USD ha −1 year −1 ) . 3.3.3  Selection of proper exploratory factors

The selection of proper causative or exploratory factors is a vital step of any model-​based spatial susceptibility zonation study. All the primary factors that are very much associated with land cover conversion and wetland shrinkage should be considered for better results of the model building studies. Here, a total of eight influencing factors (distance from lost wetlands, distance from canal, settlement density, slope, LULC, distance from road, distance from developed areas, and agricultural density) have been selected with the help of previous literature (Figure 3.4). Most of the influencing factors are based on proximity because

32  Urban Water Ecosystems in Africa and Asia

Figure 3.3 Spatial ordination of ESVs (USD/​ha/​year) in 1975, 2000 and 2021 using a. C97a, b. D12, and c. C97b unit values.

proximity from anthropogenic sources is a reasonable factor regarding wetland shrinkage. Proximity to lost wetlands is an important factor, and here, a general tendency of wetland conversion has been observed (Ghosh and Das 2020). The developed areas have always a tendency to capture their surrounding areas due to high population pressure. So, the wetlands near the developed areas have a high probability of converting to other anthropogenic purposes (Ghosh and Das 2019).

Ecosystem service valuation and risk assessment of a Ramsar site  33

Figure 3.4 Different causative factors used to assess the wetland vulnerability within EKW region based on previous studies, opinions of the native people, a. Distance from lost wetlands, b. Distance from canal, c. Settlement density, d. Slope, e. LULC, f. Distance from road, g. Distance from developed areas and h. Cropland density.

34  Urban Water Ecosystems in Africa and Asia Distance from the road is another primary factor for wetland shrinkage because different developmental activities are situated beside the roads, and increasing the distance from the communication network has a chance to decrease the influence of human factors (Sica et al. 2016). The enlargement of settlements and agricultural land is an indicator of high anthropogenic influences that can significantly decrease the area of wetlands (Ghosh and Das 2018). The developed areas have various facilities for livelihood, but some people cannot afford to build their own houses in developed areas. So, they have a tendency to make their houses adjacent to developed areas. In this way, huge percentages of wetlands are being shrieked and huge loss of wetlands has been observed. 3.3.4  Use of machine learning models

Newly emerged machine learning techniques create a new platform in classification and regression studies regarding different environmental risk assessments. Due to the high accuracy and better prediction capability in environmental studies, different machine learning (ML) algorithms are tried to apply in this research. 3.3.4.1  Support Vector Machine (SVM)

SVM is an extensively used machine learning (ML) method. This supervised machine learning binary classifier was proposed by Vapnik (Vapnik 1995), which is based on the optimal separating hyperplane concept (Vapnik 1995). The Support Vector Machine is also used as a non-​linear classifier, and it differentiates the various classes by a separating plain (hyperplane) (Hong et al. 2015). SVM model can significantly reduce the error of the complexity of a linear computation. The data processing system in SVM (in the case of a non-​linear relationship) is done with the help of the kernel function (Naghibi et al. 2017). The main advantage of SVM solves both the regression and classification problems and easily handles the huge space (Roy and Islam 2019; Saha et al. 2022; Bera et al. 2022b; Saha et al. 2023). Presently, the SVM model is used in various hazard modeling studies such as landslide modeling, flood modeling, groundwater potential zone determination, forest fire detection, etc. The hyperplane can be calculated using the formula, n

Min∑ϕi − i =1

1 n n ∑∑ϕi ϕ j yi y j ( xi x j ) (3.3) 2 i =1 j =1

Subject to, n

Min∑ϕi yi = 0 and 0 ≤ α i ≤ D (3.4) i =1

Where, x = xi , i = 1, 2 …… n, n represents the input variables and ϕi indicates the Lagrange multipliers.

Ecosystem service valuation and risk assessment of a Ramsar site  35 Decision function can be expressed as,   n f ( x ) = sgn  ∑ yi ϕi K ( xi , x j ) + a (3.5)   i= j Here, a represents a bias and K ( xi , x j ) indicates the kernel functions. 3.3.4.2  Naïve Bayes (NB)

Naïve Bayes is a classification-​based machine learning method that is based on the hypothesis, and there is no relation or dependency between maximizing the posterior probability and attributes (Soni et al. 2011). This model is based on the Bayes theorem, and the main benefit of the Naïve Bayes algorithm is that it requires a small number of training samples for classification (Bhargavi and Jyothi 2009). In this ML method, a convenience matrix has been prepared and a discriminate function has been developed for each class using Bayes theorem (Bhargavi and Jyothi 2009). Here, the Naïve Bayes algorithm has been tested for spatial modeling of wetland shrinkage in the EKW region. This ML algorithm follows, y NB =

17 argmax P ( yi ) x  P i (3.6) ∏ yi = [ event , non − event ] i =1  yi 

x  P  i  =  yi 

1 2π a

e

− ( xi − n ) 2 2a2

(3.7)

x  Here, P ( yi ) and P  i  show the prior probability and conditional probability,  yi  respectively. Whereas a & n signify standard deviation and mean respectively. 3.3.4.3  K-​nearest neighbor (KNN)

The K-​ nearest neighbor machine learning algorithm is a supervised machine learning method that is used for both classification and regression problems. Here, the proximity of the samples has been measured by a distance matrix. This distance matrix shows how comparable or dissimilar are the exploratory factors for the given samples (Adnan et al. 2020). In the case of the KNN model, the optimum number of neighbors (K) is totally dependent on the metrics that are used for the classification and regression. The KNN method is a very useful method, and it also uses contributing cases in the data, and it also classifies new cases on the basis of

36  Urban Water Ecosystems in Africa and Asia similarity indices. Here, the distance between the points is calculated using the equation, d ( xi , yi ) = ( x2 − x1 ) 2 + ( y2 − y1 ) 2 (3.8) 3.3.5  Model validation

In this research, the wetland shrinkage susceptibility over the EKW region has been analyzed using different machine learning methods (SVM, NB, and KNN). ROC (Receiver Operating Characteristics Curve) is a scientific tool for assessing the implemented models. The Area under the curve (AUC) is a synthesized index that is mainly used for validation assessment, and it can be determined from the ROC curve. In this model-​based research, sensitivity, specificity, positive predictive value (PPV), and negative predictive values (NPV) are also used as model prediction results. The AUC values can be categorized into different accuracy classes such as excellent (0.9–​1.00), very good (0.8–​0.9), good (0.7–​0.8), moderate (0.6–​ 0.7), and poor (0.5–​0.6). The ROC-​AUC stands according to the formula, n S   S AUC = ∑ ( X K +1 − X K )  S K + 1 − S K +1 − K  (3.9)  2  k =1

Here, S AUC signifies area under curve. X K follows 1-​specificity and S K follows sensitivity. 3.4 Result 3.4.1  Land use land cover transformation scenario

Various Landsat images have been used here to prepare the land use land cover (LULC) maps for the respective years (1975, 2000, and 2021). A maximum likelihood classifier has been applied for the identification of each land use land cover class separately. Here, a total of five major land use land cover classes have been identified (wetlands, settlement/​build-​up area, natural vegetation, open space, and agricultural field/​cropland) in the EKW region. The LULC maps of each year (1975, 2000, and 2021) demonstrate that wetlands and agricultural lands have been the major LULC groups in past years. But now the area of wetland is gradually decreased here. The LULC map of 1975 showed that agricultural land (41.28%) was the highest proportion of area, followed by wetland (35.12%), natural vegetation (18.68%), open land (2.79%), and settlement (2.12%) (Table 3.4). The LULC map of 2000 showed that agricultural land (43.97%) was the highest proportion of area, followed by wetland (24.65%), natural vegetation (18.59%), open land (8.08%) and settlement (4.70%) while the LULC map of 2021 demarcates that agricultural land (50.14%) has occupied highest proportion of area, followed by natural vegetation (21.70%), wetland

Ecosystem service valuation and risk assessment of a Ramsar site  37 (18.83%), settlement (7.33%) and open land (2.00%). During the overall study period (1975–​2021), the area of wetland has decreased by 46.38% whereas the highest amplification has been observed in the case of settlement (245.11%) (Table 3.4). It is assumed that the rapid human developmental activities, human encroachment and anthropogenic stresses are the responsible factors for wetland conversion in the East Kolkata Wetland area. 3.4.2  Analysis of the states of ecosystem service valuation (ESVs)

Several unit values have been adopted here for explicit analysis of ecosystem service values in the East Kolkata Wetland (EKW) area (C97a, C97b, C11, D12, and X8) for the reference years 1975, 2000, and 2021. It has been estimated that the total ecosystem service values of the EKW region are 204.04, 149.90, and 122.29 million USD for the years 1975, 2000, and 2021 respectively (Table 3.6). In the year 1975, wetlands had the highest average ESVs (185.87 (44.53–​616.91) million USD), followed by cropland or agricultural land (13.25 (0.48–​28.80) million USD) and vegetation or natural vegetation (4.56 (0.54–​9.75) million USD) (Table 3.6). In 2000, the same condition was followed. At that time, wetlands had the highest average ESVs (130.46 (31.25–​433.00) million USD), followed by cropland or agricultural land (14.12 (0.51–​30.67) million USD) and vegetation or natural vegetation (4.54 (0.54–​9.70) million USD). In the year 2021, the wetland has the highest average ESVs (99.67 (23.88–​330.81) million USD), followed by cropland or agricultural land (16.10 (0.58–​34.98) million USD) (Table 3.6). Settlement and open space contribute to the lowest ESVs in both of the years. Wetland also contributes the highest proportion of ecosystem service values but also follows a negative trend (90.46%, 85.24%, and 78.37% for the years 1975, 2000, and 2021 respectively). Simultaneously, a positive trend has been observed in the case of settlement and agricultural land. 3.4.3  Changing pattern analysis of ESVs in the study period (1975–​2021)

During the overall study period (1975–​2021), the calculated total loss of ESVs is 81.75 million USD (Table 3.7). A continuous downfall of ESVs has been observed in the East Kolkata Wetland area. A total average of 54.14 million USD losses have been detected within the year (1975–​2000), whereas an average total of 27.61 million USD loss of ESV has been observed within the period (2000–​2021). The highest loss of ESVs has been observed over wetlands (86.20 (20.65–​286.10) million USD) within the study period with a rate of 1.01% per year. A continuous downfall of ESV has been noticed in the case of wetlands. A total of 55.41 and 30.79 million loss of USD have been detected between 1975–​2000 and 2000–​2021, respectively. This is mainly due to high human encroachment and unscientific developmental activities in the main area of East Kolkata Wetland, while settlement, cropland, and forest land also follow a positive trend of ESVs in the research period (1975–​2021). The total increase of ESVs in the case of cropland is 2.84 (0.10–​6.18) million USD with a rate of 0.47% per year, whereas the total increase

38  Urban Water Ecosystems in Africa and Asia Table 3.6 Estimated ecosystem service values (ESVs) (million UDS yr-​1) using various unit values in respective years (1975, 2000 and 2021) LULC classes

Unit values

Wetland

C97a C97b C11 D12 X8 Average C97a C97b C11 D12 X8 Average C97a C97b C11 D12 X8 Average C97a C97b C11 D12 X8 Average C97a C97b C11 D12 X8 Average C97a C97b C11 D12 X8 Average

Settlement

Cropland

Forest land

Open land

Total value

Million USD ya-​1 1975

%

2000

%

2021

%

65.07 89.80 616.91 113.03 44.53 185.87 0.00 0.00 1.77 0.00 0.00 1.77 0.48 0.65 28.80 28.80 7.55 13.25 0.54 0.75 9.75 6.72 5.05 4.56 0.00 0.00 0.00 0.00 0.00 0.00 66.09 91.20 657.23 148.55 57.13 204.04

98.46 98.46 93.86 76.09 77.95

45.67 63.03 433.00 79.33 31.25 130.46 0.00 0.00 3.92 0.00 0.00 3.92 0.51 0.69 30.67 30.67 8.04 14.12 0.54 0.75 9.70 6.69 5.02 4.54 0.00 0.00 0.00 0.00 0.00 0.00 46.72 64.47 477.30 116.69 44.32 149.90

97.76 97.76 90.72 67.98 70.52 87.03 0.00 0.00 0.82 0.00 0.00 2.62 1.09 1.08 6.43 26.29 18.15 9.42 1.16 1.16 2.03 5.73 11.33 3.03 0.00 0.00 0.00 0.00 0.00 0.00

34.89 48.15 330.81 60.61 23.88 99.67 0.00 0.00 6.11 0.00 0.00 6.11 0.58 0.79 34.98 34.98 9.17 16.10 0.63 0.87 11.33 7.81 5.86 5.30 0.00 0.00 0.00 0.00 0.00 0.00 36.10 49.82 383.23 103.39 38.91 122.29

96.65 96.66 86.32 58.62 61.37 81.50 0.00 0.00 1.60 0.00 0.00 5.00 1.60 1.59 9.13 33.83 23.57 13.16 1.75 1.75 2.96 7.55 15.07 4.33 0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.27 0.00 0.00 0.72 0.71 4.38 19.39 13.22 0.82 0.82 1.48 4.52 8.83 0.00 0.00 0.00 0.00 0.00

of ESVs in the case of natural vegetation is 0.74 (0.09–​1.57) million USD with a rate of 0.35% per year. 3.4.4  Assessment of wetland conversion risk area

Three important machine learning algorithms (SVM, NB and KNN) have been applied for the delineation of wetland conversion risk assessment zones in the

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Table 3.7 Status of ecosystem service values (ESVs) for each LULC classes (1975, 2000 and 2021) using various unit values LULC classes

C97a C97b C11 D12 X8 Average Settlement C97a C97b C11 D12 X8 Average Cropland C97a C97b C11 D12 X8 Average Forest land C97a C97b C11 D12 X8 Average

ESVs (million USD)

Changes

1975

1975-​2000 (%)

2000

2021

65.07 45.67 34.89 -​19.40 89.80 63.03 48.15 -​26.77 616.91 433.00 330.81 -​183.91 113.03 79.33 60.61 -​33.69 44.53 31.25 23.88 -​13.27 185.87 130.46 99.67 -​55.41 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.77 3.92 6.11 2.15 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.77 3.92 6.11 2.15 0.48 0.51 0.58 0.03 0.65 0.69 0.79 0.04 28.80 30.67 34.98 1.88 28.80 30.67 34.98 1.88 7.55 8.04 9.17 0.49 13.25 14.12 16.10 0.86 0.54 0.54 0.63 0.00 0.75 0.75 0.87 0.00 9.75 9.70 11.33 -​0.05 6.72 6.69 7.81 -​0.03 5.05 5.02 5.86 -​0.03 4.56 4.54 5.30 -​0.02

% year1 2000-​2021 (%)

% year1 1975-​2021 (%)

-​29.81

-​1.19

-​23.60

-​1.12

121.43

4.86

55.86

2.66

6.51

0.26

14.03

0.67

-​0.51

-​0.02

16.75

0.80

-​10.78 -​14.87 -​102.19 -​18.72 -​7.38 -​30.79 0.00 0.00 2.19 0.00 0.00 2.19 0.07 0.10 4.30 4.30 1.13 1.98 0.09 0.13 1.62 1.12 0.84 0.76

-​30.18 -​41.64 -​286.10 -​52.42 -​20.65 -​86.20 0.00 0.00 4.34 0.00 0.00 0.10 0.14 6.18 6.18 1.62 2.84 0.09 0.12 1.57 1.09 0.81 0.74

% year1

-​46.38

-​1.01

245.11

5.33

21.46

0.47

16.15

0.35

(Continued)

Ecosystem service valuation and risk assessment of a Ramsar site  39

Wetland

Unit values

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LULC classes Bare land

Unit values

C97a C97b C11 D12 X8 Average Total value C97a C97b C11 D12 X8 Average

ESVs (million USD)

Changes

1975

1975-​2000 (%)

2000

2021

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 66.09 46.72 36.10 -​19.37 91.20 64.47 49.82 -​26.73 657.23 477.30 383.23 -​179.93 148.55 116.69 103.39 -​31.85 57.13 44.32 38.91 -​12.81 204.04 149.90 122.29 -​54.14

0.00

% year1 2000-​2021 (%)

% year1 1975-​2021 (%)

0.00 0.00 0.00 0.00 0.00 0.00 -​10.62 -​14.65 -​94.07 -​13.30 -​5.41 -​27.61

0.00 0.00 0.00 0.00 0.00 0.00 -​29.99 -​41.38 -​274.00 -​45.15 -​18.22 -​81.75

0.00

% year1

40  Urban Water Ecosystems in Africa and Asia

Table 3.7 (Continued)

Ecosystem service valuation and risk assessment of a Ramsar site  41 EKW region. The result of the Support Vector Machine (SVM) indicates that a total of 3007.20 ha (24%), 1127.70 ha (9%), 877.10 ha (7%), 2255.40 ha (18%) and 5262.6 ha (42%) areas are under very low, low, moderate, high and very high susceptibility classes respectively (Figure 3.5a). The SVM model also depends on several modeling parameters. Here, Eps-​regression has been used with the radial kernel. The result of Naïve Bayes (NB) indicates that a total of 2631.3 ha (21%), 1253.00 ha (10%), 1127.70 ha (9%), 2004.80 ha (16%) and 5513.2 ha (44%) areas are under very low, low, moderate, high and very high susceptibility classes respectively (Figure 3.5b) whereas the result of K-​nearest neighbor classifier indicates that total 3383.10 ha (27%), 1503.60 ha (12%), 1628.9 ha (13%), 1503.60 ha (12%) and 4510.80 ha (36%) areas are under very low, low, moderate, high and very high susceptibility classes respectively (Figure 3.5c). This is a matter of concern to the environmentalist because every model shows a high proportion of area that is under a high wetland conversion risk zone (Figure 3.6). 3.4.5  Model validation

The result of both the models shows more or less similar outcomes in the case of susceptibility zone demarcation. To evaluate the performance of the applied models, various performance determination methods have been examined. Based on the result of the Area Under Curve (AUC), it can be declared that in this scientific study, the Support Vector Machine (SVM) is the most optimal result (AUC =​0.865) associated with maximum accuracy (Table 3.8). The rest of the models also indicate a significantly better result. The AUC values from the ROC curve of the models NB and KNN are 0.830 and 0.815, respectively (Figure 3.7). Apart from this, other statistical indices have also been considered to measure the overall accuracy of the adopted models. The values of sensitivity, specificity, positive prediction value, negative prediction values, and prevalence and detection rate for the testing datasets of the model SVM are 0.8485, 0.9091, 0.9333, 0.8000, 0.6000 and 0.5091 respectively. The same values for the model NB are 0.8358, 0.8718, 0.8485, 0.8608, 0.4621, and 0.3862, respectively and 0.7692, 0.9041, 0.8772, 0.8148, 0.4710 and 0.3623 respectively for the model KNN. The present analysis signifies that SVM has the more accurate prediction capability associated with higher values of performance indicator statistics (Table 3.8). 3.5 Discussion Proper estimation of ecosystem service valuation and wetland conversion risk assessment is a prerequisite method for the management of wetland as well as wetland ecosystems. Recently, remotely based satellite images have been used as a proxy biome along with its associated value coefficient to measure or estimate the ESVs properly. Newly emerged machine learning (ML) methods provide more accurate results in environment modeling and risk assessment studies (Chen et al. 2017). In this study, the drastic change of ecosystem service value has been observed through land use and land cover dynamics. The East Kolkata

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42  Urban Water Ecosystems in Africa and Asia

Figure 3.5 Wetland conversion susceptibility maps using different machine learning models, a. SVM, b. NB and c. KNN.

Ecosystem service valuation and risk assessment of a Ramsar site  43

Figure 3.6  Bar graph showing the spatial extension of susceptibility classes that are determined using SVM, NB and KNN models. Table 3.8 Area under curve (AUC) statistics of the used machine learning models based on validation datasets Models

SVM NB KNN

Area

.865 .830 .815

Std. Error

.028 .031 .032

Asymptotic Sig.

.000 .000 .000

Asymptotic 95% Confidence Interval Lower Bound

Upper Bound

.810 .770 .753

.920 .890 .877

Wetland (EKW) also provides a variety of services, provisional services (variety of food production (organic and non-​organic), irrigation), regulatory services (water treatment, purification, regulation, pest regulation, carbon-​cycling, sub-​surface hydrology), supporting services (nutrients, habitat conservation, maintenance of soil quality) and cultural services (livelihood development and aesthetic significance) (Everard et al. 2019) (Table 3.3). Among the above-​mentioned ecosystem services, the most beneficial ecosystem services for Kolkata are food production, flood control, and water regulation (Everard et al. 2019). The shallow wetlands of this region allow sunlight to penetrate the bottom of the wetlands and help the photosynthesis process, which can significantly increase the blooming of phytoplankton. These wetlands create a complicated ecosystem function and biodiversity. Since the 18th century, the pattern of land use and land cover of this area has been drastically altered mainly due to land reclamation, massive siltation, and alteration

44  Urban Water Ecosystems in Africa and Asia of industrial and municipal sewage (Ray Chaudhuri et al. 2012).In 1945, about 20000 acres of land in East Kolkata Wetlands was covered by water bodies, out of which approximately 18000 acres were utilized for waste water-​based pisciculture (including 350 fisheries). In 1956, the Salt Lake Reclamation Scheme (SLRS) was adopted, and almost half of the wetland area was reclaimed for the development of Salt Lake Township to reduce the huge population pressure in Kolkata. Approximately 3000 acres of water bodies were filled up with the help of the silt obtained from river Hooghly for altering the wetlands into Salt Lake satellite city during 1962–​1967. Later, during the time period of 1967–​1972, a further 800 acres of low-​lying areas were transformed into elevated land to extend Salt Lake City. In 1972, about 11480 acres of land was allotted for the purpose of sewage-​based pisciculture, and the rest of 1650 acres were further acquired for the establishment of East Kolkata Township. Afterward, around 600 acres of land were reclaimed to develop real estate at Patuli. It is noteworthy that in 1980, a segment of additional wetland was reclaimed to construct the Eastern Metropolitan Bypass (EM Bypass), while the Municipal Solid Waste Disposal Ground was also established within the EKW region. Although the substantial water bodies covered the maximum part of the area but recently the indiscriminate conversion of the wetlands disrupts the natural and socio-​economic equilibrium of this region (Bera et al. 2021b). The present remote sensing-​based study shows that the coverage of water bodies has been notably reduced in the EKW region due to the rapid and unplanned sprawling of agricultural land and built-​up areas. Applying geospatial techniques, it is stated that the land use or land cover of the EKW region has been tremendously modified in the contemporary era due to excessive population pressure upon Kolkata Metropolitan city, and subsequently, rapid conversion is taking place in different pockets of the EKW region. Simultaneously, the natural ecological balance or ecosystem stability has been hastily disturbed. As a result, many critically endangered and vulnerable species have been removed from this natural ecological habitat in the vicinity of Kolkata Metropolitan City (Bera et al. 2021b; Das et al. 2021; Maity et al. 2022). A total of eight influencing factors have been significantly used in this model-​building study for wetland conversion risk assessment. Model validation result provides that the Support Vector Machine (SVM) model has better prediction capability in this wetland shrinkage assessment study with respect to Naïve Bayes (NB) and K-​nearest neighbor (KNN) on the basis of its prediction-​based statistical indicators (Figure 3.7). The results of the models show that high-​risk and very high-​risk zones are situated in the adjacent areas of the Kolkata megacity and the middle section of the study area. The entire high and very high-​risk areas are associated with developmental activities, well-​connected transport networks, and developed areas. The low susceptibility zones are restricted in the eastern and southeastern parts of the wetland area. The shrinkage of wetlands also leads to the degradation of the environment of the surrounding areas and creates an alarming situation for the city planners or the governments as it refines the sewage water which is generated from Kolkata city and its surrounding areas (Gupta et al. 2016). The fragmentation or reduction of the wetland areas decreases the water-​holding

Ecosystem service valuation and risk assessment of a Ramsar site  45

Figure 3.7 ROC-​CURVE shows the prediction capability of the used models.

capability and purifying proficiency of sewage water, and this area also plays a significant role in carbon sequestration, which also decreases day by day (Pal 2018). The reduction of wetland areas in the EKW region also increases the probability of urban flooding (Rumbach 2017). At last, it can be concluded that this study tries to identify the dynamic pattern of ESVs and wetland conversion risk zones on the basis of three different machine learning models to adopt more effective plans regarding wetland shrinkage and its associated environmental degradation process. An extensive literature review regarding ecosystem services has recognized that this region also provides many ecosystem services (food production, storm regulation, etc.). The term ‘East Kolkata Wetland’ is linked with a range of terms of ecosystem services (provisioning, regulatory, cultural, supporting, food, nutrients, treatment, purification, birds, and carbon). A wide variety of factors are responsible for the environmental degradation of EKW and ecosystem services. Real estate companies, government organizations, and promoters are intruding into the area and making a threat to the wetland. The rapid expansion of urban infrastructure in the Bidhannagar Municipality also creates extra problems for the health and ecosystem services of the wetlands (water quality deterioration, aquatic pollution, eutrophication, and wetland degradation). The agricultural expansion and associated development of aquaculture activities have been continuously encroaching into the EKW (Mondal 2017).

46  Urban Water Ecosystems in Africa and Asia 3.6 Conclusion This GIS-​based study gives a clear illustration of the wetland shrinkage process, associated effects and related factors. Generally, the East Kolkata Wetland (EKW) has inherent characteristics of a resource recovery process or system that is beneficial for the local dwellers and also the city dwellers. The wetlands are also of paramount importance for maintaining the ecological balance and environmental sustainability. This scientific study evaluates the dynamic pattern of ecosystem service valuation (ESVs) and demarcates the wetland conversion risk zones in East Kolkata Wetland. A comparison between the employed models shows that SVM has a high predictive power. This study also shows that the area of EKW adjacent to the Kolkata metropolitan area has a greater risk of conversion. Costanza et al. (1997) estimated that ecosystem service values (ESVs) of wetlands are 75% more than lakes, rivers, and waterbodies, 15 times more valuable than forest land, and 64 times higher values than rangelands and grassland. All three models clearly illustrate that the western, middle, lower middle, and southeastern parts have high wetland conversion probability. Construction of the EM (Eastern Metropolitan) bypass and Salt Lake satellite town apparently provides various social and economic benefits, but it creates a challenging condition for the environmentalists for the protection of the EKW region. Recently, the conservation of this natural resource has become difficult for real estate agents and developers. Their illegal encroachment can hamper the natural environmental balance of this region and create social, environmental, and ecological imbalance over the EKW region (Kundu and Chakraborty 2017). A drastic change in land use pattern has been observed over the EKW region for the last 25 years. The area of the fish farm was reduced from 7300ha in 1945 to 5842ha in 2003, which is associated with the construction of roads and settlements. The declining trend of wetlands has significantly reduced the capability of wastewater treatment and attenuates floods. The decline of wetlands and their treatment process not only affects the natural ecosystem of this region but also affects the productivity and the provisional ecosystem services that we get from this area (Kundu and Chakraborty 2017). Some wetlands have been transformed into eutrophic stages due to a huge accumulation of nutrients in the wetlands, and living organisms are suffering due to oxygen deficiency, and turned into an aquatic environmental disaster (Bera et al. 2021b). So, formulation of strict rules and regulations should be imposed over this area for the maintenance of the natural habitat of this unique, ecologically diverse area. The EKW management and conservation ordinance came into force in 2005. On 31st March 2006, the West Bengal Legislature passed this ordinance into an Act, namely the East Kolkata Wetlands Act 2006. After that, EKWMA (East Kolkata Wetland Management Authority) was developed. The primary function of EKWMA was to prevent unauthorized development under the area and maintain the ecological balance properly (Kundu et al. 2008). Further researches are needed in the EKW region to carefully investigate the reasons behind environmental degradation in the EKW region and successfully implement rules and regulations. At the end of the conclusion section, the authors suggest some potential management techniques for

Ecosystem service valuation and risk assessment of a Ramsar site  47 sustainable environmental management. Regular removal or dredging of sediments from the wetlands is highly required for the health of the wetlands. Canal water treatment units should be installed at different points of the EKW region. Rainwater harvesting can lead to better utilization of agricultural land. A recycling unit (plastic waste) has been proposed for development in this region. The use of chemical fertilizers should be restricted within the EKW region. Local community advisory groups should be needed for the management of the local resources and to enhance the productivity of the region. References Adnan MSG, Rahman MS, Ahmed N, Ahmed B, Rabbi MF, Rahman RM. 2020. Improving spatial agreement in machine learning-​based landslide susceptibility mapping. Remote Sens. 12:3347. https://​doi.org/​10.3390/​rs1​2203​347 Ancog R, Ruzol C. 2015. Urbanisation adjacent to a wetland of international importance: The case of olango island wildlife sanctuary, metro cebu, Philippines. Habitat Int. 49:325–​332. http://​dx.doi.org/​10.1016/​j.hab​itat​int.2015.06.007 Bagchi K. 1944. Stages in formation of Ganges Delta. The Ganges Delta. University of Calcutta, Calcutta, India, pp. 50–​71. www.world​cat.org/​title/​gan​ges-​delta/​oclc/​7321​315 Bera B, Bhattacharjee S, Sengupta N, et al. 2022a. Significant reduction of carbon stocks and changes of ecosystem service valuation of Indian Sundarban. Sci. Rep. 12:7809. https://​doi.org/​10.1038/​s41​598-​022-​11716-​5 Bera B, Bhattacharjee S, Shit PK, Sengupta N, Saha S. 2021b. Anthropogenic stress on a Ramsar site, India: Study towards rapid transformation of the health of aquatic environment. Environ Challenges. 4:100158. https://​doi.org/​10.1016/​j.envc.2021.100​158 Bera B, Shit PK, Saha S, Bhattacharjee S. 2021a. Exploratory analysis of cooling effect of urban wetlands on Kolkata metropolitan city region, eastern India. Curr Res Environ Sustain. 3:100066. https://​doi.org/​10.1016/​j.crs​ust.2021.100​066 Bera B, Shit, PK, Sengupta, N, Saha S, Bhattacharjee S. 2022b. Forest fire susceptibility prediction using machine learning models with resampling algorithms, Northern part of Eastern Ghat Mountain range (India). Geocarto Int. 37:11756–​11781. https://​doi.org/​ 10.1080/​10106​049.2022.2060​323 Bhargavi P, Jyothi S. 2009. Applying naive bayes data mining technique for classification of agricultural land soils. Int J Comput Netw Inf Secur. 9:117–​122. Chakraborty G, Das Gupta D. 2019. From conflict to co-​production: A multi-​stakeholder analysis in preserving the East Kolkata Wetlands. Forum for policy Dialogue on Water Conflicts in India, Pune, India, pp. 1–​45. www.wat​erco​nfli​ctfo​rum.org/​lib_​d​ocs/​Rep​ort-​ East-​Kolk​ata-​Wetla​nds.pdf Chaudhuri RS, Mukherjee I, Ghosh D, Thakur AR. 2012. East Kolkata Wetland: A multifunctional Niche of International importance. Online J Biol Sci. 12(2):80–​88. https://​doi. org/​10.3844/​ojb​sci.2012.80.88 Chen L, Jin Z, Michishita R, Cai J, Yue T, Chen B, Xu B. 2014. Dynamic monitoring of wetland cover changes using time-​series remote sensing imagery. Ecol. Inform. 24:17–​26. http://​dx.doi.org/​10.1016/​j.eco​inf.2014.06.007 Chen W, Xiaoshen X, Wang J, Pradhan B, Hong H, Dieu TB, Zhao D, Ma J. 2017. A comparative study of logistic model tree, random forest, and classification and regression tree models for spatial prediction of landslide susceptibility. Catena 151:147–​160. https://​doi. org/​10.1016/​j.cat​ena.2016.11.032

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4 Impact of water shortage and climate change on peri-​urban agriculture in Tunisia Mohamed Kefi and Chokri Dridi

4.1 Introduction Water is a renewable but limited resource that is becoming progressively rarer due to population growth and economic activities and its vulnerability is further aggravated by the impacts of climate change (MacAlister et al., 2023). In addition, climate change has increased water stress, especially in regions characterized by limited precipitation and where groundwater is already depleted, affecting agriculture and population (UNEP, 2021). It is estimated that about 2.3 billion people live in water-​stressed countries, of which 733 million live in high and critically water-​ stressed countries (UN-​Water, 2021). Additionally, agricultural water scarcity is projected to be more important in more than 80% of global croplands by 2050 (Liu et al., 2022). Climate significantly contributed to water stress in all regions of the world, with a particular effect in Africa. This impact could disrupt agricultural activities as 95% of arable land in sub-​Saharan Africa is rainfed (Bhattacharyya et al., 2013). Indeed, higher temperatures have led to a 34% decline in the growth of agricultural productivity in Africa since 1961 (WMO, 2022). This pattern is expected to continue in the future, increasing the risk of food insecurity and malnutrition. It was estimated that wheat yield in Southern and North Africa will reduce by 20%–​60% (WMO, 2022). Climate change will also have severe implications for jobs and work productivity (WMO, 2022). With climate change causing unpredictable rainfall and increasing flood and drought risks, there is an important need to prioritize investments in improved water management and infrastructure (Mason et al., 2019). Moreover, in water-​ scarce regions affected by climate change, accessing water for agricultural production requires effective adaptation measures and strategies to improve water security and promote sustainable agriculture. In this context, the main challenge is to implement operative water resource management to optimize economic and social well-​being under large hydrometeorological uncertainties (Chang and Wang, 2013). Some researchers developed approaches and techniques for reducing water allocations to meet irrigation demands under the influence of climate change (Chavez-​Jimenez et al., 2014). In addition, the deficit irrigation approach can be a significant solution to save water by taking into account plant physiological regulations (Du et al., 2015). In fact, deficit irrigation DOI: 10.4324/9781003437833-4

Impact of water shortage and climate change in Tunisia  53 is an optimization scheme in which irrigation is applied during drought-​sensitive growth stages of a crop (Geerts and Raes, 2009). Tunisia, as many countries in the MENA region, is a water-​stressed country with an arid and semi-​arid climate. The total amount of renewable water resources per capita is estimated at 420 m3 per inhabitant per year, which is considered an important indicator of water scarcity (BPEH, 2021). The agriculture sector is the largest consumer of water with about 75% of freshwater usage compared to other sectors (BPEH, 2021). To maintain and increase agricultural productivity, the Tunisian government supported irrigated agriculture. In this situation, the main challenge for decision-​makers is to supply and protect water for irrigation purposes in the face of water scarcity. Therefore, the main objective of this research is to assess water shortage considering the impact of climate change and its effects on agriculture production. The analysis is applied at the Lebna irrigated perimeter in Nabeul. The approaches are based on monitoring of surface water of the dam and the assessment of the impact of water irrigation deficit for crops in the study area considering climate change projections. This study can be significant for local stakeholders to develop sustainable measures aimed at mitigating the vulnerability of agricultural water management to the impacts of climate change. The next section presents the materials and methods with a focus on the study area description, the approach applied to assess water surface and to estimate water deficit. Section 3 will present the main results of this work, and the final section concludes the main outcomes of this research. 4.2  Materials and methods 4.2.1  Study area

The Lebna watershed area is located in the governorate of Nabeul, the northeast part of Tunisia (Figure 4.1a). It covers an area of about 210 km2 of mountainous terrain and plains. The watershed is mainly covered by forest, agricultural land, and rangeland. The annual rainfall in the area is estimated at about 478 mm. Lebna Dam was constructed in 1986, and its capacity is about 30 million m3. However, the capacity of water availability depends on the rainfall and water inflow. The dam serves for groundwater recharge, water supply for irrigation and domestic use (drinking water), and the protection of downstream areas (Kefi et al. 2017). Three irrigated perimeters and the national drinking water company are using water from the Lebna reservoir. In this study, we focused on the Lebna Dam perimeter, which is managed by a water user association called GDA (Figure 4.1b). The GDA is responsible for water allocation to farmers based on volume-​based fees designed to cover maintenance and operation costs. Water from the Lebna reservoir is used for irrigating the surrounding perimeter, with an area of 450 ha. The cropping system is characterized by summer and winter crops. The main crops are tomato (13.3% of total land), pepper (14.8%), strawberry (24%), potato (0.9%), barley (32%), citrus (10%), and olive (5%) (Dridi et al., 2023). The average water usage from the dam allocated for farmers is approximately 1.7 million m3. However, the allocation for farmers depends on the availability of water in the reservoir.

newgenrtpdf

54  Urban Water Ecosystems in Africa and Asia

Figure 4.1 Study area location.

Impact of water shortage and climate change in Tunisia  55 Table 4.1 Satellite remote sensing data used Satellite sensor

Date of Path/​Row Pixel acquisition size

Landsat 8 OLI L2 23-​07-​2023 191/​34 30-​07-​2020 17-​07-​2015 Landsat 5 TM L2 04-​08-​2010 05-​07-​2005 23-​07-​2000 24-​06-​1995 28-​07-​1990 02-​06-​1987

30 m

Spectral Band used to assess resolution MNDWI 8 Bands

B3 (Green) B6 (SWIR)

6 Bands

B2 (Green) B5 (SWIR)

4.2.2  Surface water monitoring

The multi-​temporal satellite images of the Lebna reservoir were used to study and analyze the evolution of water bodies. Landsat images (Landsat 8 and Landsat 5) Level 2 were downloaded from the USGS platform (https://​earthe​xplo​rer.usgs. gov/​). In order to evaluate the dynamics of water body changes of the Lebna dam, nine satellite images from the construction of the dam (the year 1987) to the current situation (the year 2023) were selected and used to generate Modified Normalized Difference Water Index (MNDWI) as it was presented in Table 4.1. For clarity, the selection of images focused on scenes with a cloud cover rate of less than 10%. MNDWI was developed by Xu (2006) and it is an accurate index to detect open water features as reservoirs. The MNDWI can be expressed as follows: MNDWI = �

Green − SWIR Green + SWIR

Green =​pixel values from the green band SWIR =​pixel values from the short-​wave infrared band Moreover, the reservoir inflow depends totally on rainfall in a river basin. Reservoir storage is influenced by seasonal rainfall. In this context, remote sensing datasets describe the location and spatial extent of the Lebna reservoir. Additionally, MNDWI was generated and extracted from multi-​temporal satellite images to monitor surface water from the Lebna dam reservoir. This indicator can optimize irrigation water use and also assess water deficit. 4.2.3  Water deficit evaluation 4.2.3.1  Model description

We develop a deficit management model calibrated for the study area. The model uses the crop response function developed by the FAO (Doorenbos

56  Urban Water Ecosystems in Africa and Asia and Kassam, 1979). The crop response function is modified to account for crop growing stages (Varzi, 2016). FAO identifies four growing stages; initial, developmental, mid-​season, and late season. While the number of growing stages is identical for all crops, they do not start or end at the same time for all crops; growing stages are staggered and are not necessarily of the same length. The objective of the model is to minimize the loss of profit due to irrigation deficit. The key variable that the model determines is the optimal irrigation deficit for a specific crop during a given growing stage, for a given month, and for every ten days in that month. The breakdown by month and 10-​day period (as opposed to a breakdown by growing stage) is necessary, as it allows having irrigation deficits, and therefore allocations by 10-​day period or by month, which is more meaningful from an irrigation and scarcity management perspective. Among the model results of particular interest is what is known as the Lagrange multiplier; it represents the marginal economic value of water in the irrigation district when water is scarce. In its Sixth Assessment Report (IPCC, 2023), the Intergovernmental Panel on Climate Change (IPCC) identifies five greenhouse gas emissions scenarios leading to climate change impacts with varying degrees of severity. In this work, we use the climate change scenario identified as SSP1-​1.9 for the analysis. This is considered the most optimistic scenario where global temperature increase is limited to 1.5°C in most cases. This scenario is compatible with the 2015 Paris Agreement’s objective. 4.2.3.2  Data analysis and processing

Data from the irrigation perimeter covers four years, from 2011 to 2014. The land is occupied by seven crops: barley, citrus, olive, pepper, potato, strawberry, and tomato. The survey was conducted with local water managers of the Water User Association (GDA), and some local farmers. We gathered data about crops and yields from about 58 active farmers in 2011, 62 in 2012, 74 in 2013, and 66 in 2014. These farmers are operating respectively in 90, 94, 110, and 94 parcels of land of various sizes within the irrigation perimeter. For each crop, we employed prices and average production cost, not inclusive of water fees, from Benalaya et al. (2015). These inputs were used to calibrate the loss of profit resulting from the irrigation deficit, which is the objective function of the model. The FAO’s software CLIMWAT 2.0 for CROPWAT 8.0 (Smith, 1993) generates a climate file for the Kelibia weather station (Lon.: 11.08°, Lat.: 36.85°, Alt.: 30m), a station very close to the study area. It contains, among other data, the average sun hours per month. The pluviometry (USDA SC Method for computation of effective rain), average monthly temperature, humidity, and wind data for the period 2010–​14 are from Tunisia’s National Institute of Meteorology. These data were incorporated in CROPWAT (Smith, 1992) to generate the irrigation requirement per 10-​day period for each of the crops. Regarding the irrigation system, the potential efficiency of surface drip irrigation systems is typically between 85% and

Impact of water shortage and climate change in Tunisia  57

Figure 4.2 Total water requirement and irrigation requirement.

95% (Irmak et al., 2011). For this work, an average value of 90% was selected. The planting date is chosen according to current practices in the focus area (Allen et al., 1998; Benalaya et al., 2015). In addition, the growing season runs from September to August. Figure 4.2 illustrates for each year under consideration, the study area’s monthly water requirements and the part that needs to be fulfilled through irrigation, with the gap being fulfilled with rainfall. It shows a strong reliance on rain between September and May. Figure 4.3 shows similar data as in Figure 4.2 but uses climate change scenario SSP 1-​1.9 projections for the period 2080-​2099. We notice that starting from February total water requirement and irrigation requirement increased by between 50% and 100%. We detect also that in relative terms, there is a stronger reliance on irrigation as illustrated by the narrower gap between total water requirement and irrigation requirement. However, as temperatures are expected to rise and rainfall to decrease, there will be less dependence on rain-​fed agriculture.

58  Urban Water Ecosystems in Africa and Asia

Figure 4.3 Total water requirement and irrigation requirement under climate change.

4.3 Results Water mobilized from the Lebna dam serves both irrigation and drinking water purposes. However, the reservoir’s capacity is influenced by precipitation. As illustrated in Figure 4.4, the temporal distribution of the water surface is constantly changing. Lebna Dam was constructed in 1986. The area of the reservoir estimated from MNDWI of 1987 is about 6.407 Km2. However, in 2023, the spatial extent generated from MNDWI is about 1.215 Km2. Additionally, the amount of water stored in the reservoir varies depending on precipitation. Figure 4.5 illustrates the correlation between rainfall and reservoir filling. We can note that the Lebna reservoir’s volume is low due to limited precipitation. The decrease in reservoir capacity will lead to a reduction in the irrigated area within the nearby perimeter. This decrease in reservoir capacity may impact farmers’ income and could affect food security.

Impact of water shortage and climate change in Tunisia  59

Figure 4.4 Variation of spatial extent of the reservoir.

Figure 4.5 Relationship between reservoir filling and rainfall.

60  Urban Water Ecosystems in Africa and Asia Figure 4.6 clearly illustrates the dynamic changes in the spatial extent of the reservoir. It is evident that the dam’s area decreases dramatically compared to the initial dam filling. In 2023, the decrease in the extent of water is about 81%. This variation may affect water supply for irrigation and drinking water and it will not satisfy water demand for all users. In this context, climate change adaptation measures will be necessary to address this water issue. Figure 4.7 depicts the study area’s optimal total monthly irrigation deficit by month and by year. The deficits coincide with months when effective rain is relatively low. The irrigation deficit is observed during September and then between March and July, with May being the month where the highest irrigation deficit takes place. Figure 4.8 shows that barley, pepper, tomato, and citrus are the crops where most of the irrigation deficit takes place, while olive, being a drought-​resistant crop, suffers only a moderate irrigation deficit. The results also show that for high-​ value crops like potatoes and strawberries, little to no irrigation deficit should take place at any stage, as that would have the highest economic loss (Figure 4.8). A close look into the breakdown of the irrigation deficit by growing stage shows that during the initial stage, no irrigation deficit takes place for any of the crops, as that would hamper crop growth. Otherwise, deficits for the other crops should occur predominantly in the mid-​season and late season. Table 4.2 shows the results of regressions of average irrigation deficit (mm/​ ha) regressed against the land surface covered by each crop in the study area. Where statistically significant, the results indicate that growing barley, citrus, olive, pepper, and tomato leads to an increase in the average irrigation deficit in the study area, while growing strawberries reduces the average deficit. For potatoes the regression coefficients are not statistically significant, therefore no relationship could be inferred. Figure 4.9 shows the economic value of water as the irrigation deficit is increased; the result of this sensitivity analysis shows that the value of one cubic meter of water could be near 10 TND/​m3 if the water shortage intensifies. The optimal irrigation deficit under IPCC climate change scenario SSP 1-​1.9 is illustrated in Figure 4.10. Compared to Figure 4.8, the extent of the shortage is much more severe for all crops at all stages of growth. The cumulative shortage is roughly between 1.5 and 2-​fold higher for all crops. We also observe that a shortage in irrigation is expected to occur during the initial growth stages for citrus, olive, and tomatoes. For strawberries, which are high-​value crops, the irrigation shortage is expected to be even more severe. Moreover, citrus, a specialty of Nabeul, will need to be deprived of irrigation at all stages of growth. Although our model cannot predict crop rotations or substitution, it is likely that some crops need to be abandoned in favor of other more drought-​resistant crops. While the climate scenario we considered is viewed by the IPCC as optimistic, a fundamental change in the cropping system will undoubtedly have an impact on land use, livelihoods, and employment in the region.

Impact of water shortage and climate change in Tunisia  61

Figure 4.6 Variation of Lebna reservoir.

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62  Urban Water Ecosystems in Africa and Asia

Figure 4.7 Monthly total irrigation deficit and monthly effective rain.

Impact of water shortage and climate change in Tunisia  63

Figure 4.8 Irrigation deficit by growth stage and by crop.

4.4 Conclusion Climate change includes changes in precipitations and temperature that affect evapotranspiration and agricultural production. The reduction in agriculture production in peri-​urban areas creates reasons for local farmers to migrate to larger and more affluent cities. Indeed, a decrease in agriculture productivity in peri-​ urban agriculture had a direct impact on farmers’ revenues. It can also reduce food availability for local markets and beyond. Considering that most of the farms in the study area are small-​scale operations and are generally family-​owned; farmers facing declining crop yields and income have to seek employment in other sectors and possibly in urban areas. In order to cope with the consequences of water shortage and the effects of climate change, Tunisian policymakers established two

64  Urban Water Ecosystems in Africa and Asia Table 4.2 Determinants of average irrigation deficit Average irrigation deficit (mm/​ha)

Barley Citrus Olive Pepper Potato Strawberry Tomato Observations Adjusted R2 Note:

2011

2012

2013

6.789*** (2.503) 6.331* (3.397) 11.620* (5.948) 50.560*** (6.612) -​54.890 (77.240) -​5.524* (3.159) 26.050*** (7.862) 90 0.657

10.840*** 10.000*** (2.739) (2.703) 2.865 4.561** (2.013) (2.209) 12.930** 7.545 (6.176) (6.708) 50.290*** 29.830*** (8.439) (7.441) -​29.090 -​41.250 (28.130) (40.370) -​7.507*** -​5.900** (2.652) (2.512) 11.190 30.370*** (8.923) (7.571) 94 110 0.600 0.547 * p 60 % > 60 % Up to 30 % Up to 30 % Up to 30 % > 8 sq. m.

(Continued)

Assessing human health risks associated to water stress  147

1. Per capita municipal < 60 lpcd 60 –​80 lpcd 80 –​100 lpcd 100 –​120 lpcd water supply 2. Municipal water supply 81 –​100 % 60 –​80 % 41 –​60 % 21 –​40 % source -​ Dependency on GW sources Dependency on surface 0 –​20 % 21 –​40 % 41 –​60 % 60 –​80 % water 3. The main source of drinking water –​score assigned as per the % and weighted average shall be done Tap water from treated Up to 30 % -​ 31 –​60 % -​ source Tap water from an Up to 30 % -​ 31 –​60 % -​ untreated source Covered well Up to 30 % -​ 31 –​60 % -​ Handpump > 60 % -​ 31 –​60 % -​ Tube well/​borehole > 60 % -​ 31 –​60 % -​ Other sources > 60 % -​ 31 –​60 % -​ 4. The area under parks, > 0 –​1 sq. m. 1 –​3 sq. m. 3 –​5 sq. m. 5 –​8 sq. m. playgrounds, open spaces and forest area –​as per URDPFI min of 8 sq. m per capita

5

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5. Proximity to a government hospital 6. No. of private. health care establishments 7. Semi-​Pucca /​ Kuccha Road 8. Sewer system 9. Coverage of storm water drainage network 10. Literacy rate 11. Females per 1000 males 12. % of the main worker 13. % of the marginal worker

Score Thresholds (Normalization) 1

2

3

4

5

Beyond 5 km

Within 5 km

Beyond 3 km

Within 3 km

Within 1 km

0 –​5

6 –​11

12 –​20

21 –​35

36 –​81

81 –​100 %

61 –​80 %

41 –​60 %

21 –​40 %

0 -​20 %

0 -​20 % 0 -​20 %

21 –​40 % 21 –​40 %

41 –​60 % 41 –​60 %

61 –​80 % 61 –​80 %

81 –​100 % 81 –​100 %

less than the % share at city-​level less than the % share at city-​level less than the % share at city level more than the % share at city level

-​

equal to the % share at city-​level equal to the % share at city-​level equal to the % share at city level equal to the % share at city level

-​

more than the % share at city-​level more than the % share at city-​level more than the % share at city level less than the % share at city level

-​ -​ -​

-​ -​ -​

148  Urban Water Ecosystems in Africa and Asia

Variable

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Annex. B –​Characteristics of the selected wards Ward 15

Name Target sample size 20 Population (census 2011) No. of households Decadal pop. growth factor Literacy rate Working population Main source of drinking water

Sarojani Nagar-​II 40 46057 8601 2.18 times 74.18% 31.67% Handpump and Boreholes

Ward 11

Ward 30

Chinhat Shankar Purwa-​II 45 45 54513 53630 10850 10335 2.13 times 3.55 times 72.90% 73.65 % 31.46% 30.51 % Tap water from Tap water from treated source treated source Municipal water supplied 100 lpcd 295 lpcd 120 lpcd Municipal water supply source Tube wells Water Works and Tube wells Nearest govt. healthcare facility Beyond five km Within a km Within 1–​3kms The wards are referred using their ward number rather than their names

Ward 46

Golaganj 20 24264 10335 1.385 times 71.85% 33.11% Handpump and borehole 276 lpcd Within a km

Assessing human health risks associated to water stress  149

Characteristic

150  Urban Water Ecosystems in Africa and Asia Annex. C –​Household survey questionnaire Location _​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​ Form No. _​_​_​_​ Date _​_​_​_​_​_​_​_​_​_​ Family Size:

Religion:

House Tenure ship: ▢ Own ▢ Rented ▢ Encroachment

Member no.

1

2

3

4

5

6

Gender (M/​F) Age Education Occupation Living since:

Earlier residence:

Reason for migrating:

Monthly Expenditure: Building Characteristics –​ Structure type ▢ Kuccha ▢ Pucca ▢ Semi-​pucca Condition -​ ▢ Good ▢ Livable ▢ Dilapidated Building Use –​▢ Commercial ▢ Public-​Semi-​public ▢ Mixed-​Use ▢ Residential Plotted -​ ▢ Detached ▢ Semi Detached ▢ Single-​storey housing ▢ Duplex Apartments ▢ G+​3 ▢ Up to G+​3 ▢ > G+​7 WATER CONSUMPTION PATTERN i. Source of potable water supply -​▢ Municipality ▢ Handpumps ▢ Tube well ▢ Bore Well ▢ Multiple sources ii. Water utilization

W.S. Source 1

W.S. Source 2

Good /​Moderate /​ Remarks Bad

Good /​Moderate /​ Remarks Bad

Type Used for Dependency (in %) Quality

Assessing human health risks associated to water stress  151 iii. Is the water supplied, sufficient? ▢ YES ▢ NO; If No, the alternative source, _​ _​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​ iv. Storage capacity of individual water tank –​ _​_​_​_​_​_​_​_​_​Stored water is sufficient for? ▢ ½ day ▢ 1 day ▢ 2 days v. Method of treating drinking water -​▢ None ▢ R.O. ▢ Aqua guard ▢ Chlorine Tablets ▢ Boiling ▢ Other _​_​_​_​_​_​_​_​_​_​ vi. Any water tariff or taxes? ▢ YES ▢ NO; If yes, the amount _​_​_​_​_​_​_​_​_​_​_​_​_​_​ _​_​_​_​_​_​_​_​_​_​_​_​_​_​_​_​ vii. Reuse of waste water? ▢ YES ▢ NO; Rainwater harvesting -​▢ YES ▢ NO; If Yes ▢ building level ▢ community level viii. Sewage Disposal -​▢ Individual Septic Tank ▢ Community Septic Tank ▢ Discharge into drains ix. Solid Waste –​ a. D to D Collection ▢ YES ▢ NO b. Cleaning common bins -​▢ Daily ▢ Twice a W ▢ Once a W ▢ Once in 2W c. Improper SWM ▢ Clogged drains (overflowing) ▢ Attracts animals and vectors ▢ Foul Smell ▢ Other _​_​_​_​_​_​_​_​_​_​

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Diseases suffered from in the past

Summer (March –​June) 1

2

3

4

5

Monsoon (July –​September) 6

1

2

3

4

5

Winter (October –​February) 6

1

2

3

4

5

6

Typhoid Dysentery Diarrhea Viral Hepatitis A /​E Dengue Malaria Skin problems Other problem Proximity

Name and Address

1 =​Within a km; 2 =​1-​3 Km; 3=​3-​5 Kms; 4=​beyond 5 Kms Govt. hospital Pvt. clinic dispensary Multi-​specialty Hospital x. What is your opinion of the degraded water quality and its effects of people’s health? xi. Other Experiences or Opinions relevant for this study

Reason for Choosing 1=​Proximity; 2=​Better Service; 3=​Less expensive; 4=​Any other

152  Urban Water Ecosystems in Africa and Asia

HEALTH PROFILE AND INFRASTRUCTURE ACCESS

9 Water ecosystem management in Japan Successes and failures Shamik Chakraborty, Gowhar Meraj, Pankaj Kumar, and Amit Chatterjee 9.1 Introduction Island rivers are some of the fundamental and important geographical processes on island landscapes that are surrounded by seas. These rivers represent an interface between land, air, and water, and often produce remarkable freshwater biological diversity. In their natural state, these rivers are dynamic and physically and biologically complex, showing unique connectivity between (riverine) ecosystems and the basin society. Japan is an island country blessed with rich water resources, almost all of which are not generated within the country and are carried in by moisture-​laden air movements through the Sea of Japan (winter snowfall), the Indian Ocean (monsoon rainfall), and the Philippine Sea (typhoon season). Rivers in Japan represent characteristics of island rivers in the Asian monsoon climate. The abundant year-​round precipitation with the typical island topography has given rise to rivers that are short with steep gradients to carry water and sediments quickly out to the sea (Takahashi and Uitto, 2004). Although short in comparison to continental rivers, these rivers have also supported the growth of some of Asia’s biggest urban growth, and in the process, have received significant alterations and modifications of their basin environment (Totman, 1998; Chakraborty, 2013a), sacrificing parts of the basin for the economy. Some of the most tell-​tale modifications include pollution of rivers (Otsuka et al., n.d.), concretization of beds and banks (Michaud, 2015), channel straightening, and building of dams (Chakraborty, 2013a). Japan’s river basin restoration has been dominated by pre-​and post-​Second World War pollution incidents. Japan saw some specific (unsustainable) development processes. Otsuka et al. (n.d.) noted that in the pre-​Second World War era, Japan was plagued by some serious pollution incidents in several of its river basins due to weak environmental legislation and following a primarily Western mode of development path; this trend continued in the post-​Second World War era. However, during this time, local governments also started to act due to the absence of national laws for pollution control. The Tokyo pollution control ordinance and Osaka pollution control ordinance for their factories were established in 1949 and 1950 respectively. However, these cases of successful pollution control ordinances remained rare, and other cities continued to experience the full effect of environmental degradation. Some prominent examples are given by the Minamata DOI: 10.4324/9781003437833-9

154  Urban Water Ecosystems in Africa and Asia disease in the Ariake Sea area (Kumamoto Prefecture), ‘itai-​itai’ disease in Jinzu River (Toyama Prefecture), and Yokkaichi asthma due to severe air pollution in the Yokkaichi industrial belt (Mie Prefecture). Public opinion started to emerge as a powerful tool for combating pollution incidents due to urban developments. The formation of Basic Environmental Law in 1970, along with 14 other laws for pollution control, were established, and in the following year, the Environmental Agency was created for environmental conservation in Japan. The Environmental Quality Standard law enabled a system where polluters of public water systems needed to pay a penalty. During this time also, bottom-​up citizen-​led approaches started to gain to retard the stronghold of technocentric national development plans (Ui, 1992). During the 1990s, the country was starting to see new ventures against unsustainable river basin utilization, and more emphasis on the restoration of waterway ecosystems and the fight against pollution. This awareness and development in Japan were perhaps part of the general trend seen in the world from the 1980s (Chakraborty, 2013b). The river law was established during this time with the word tashizengata kawazukuri put into effect, which incorporates more ecosystem-​based engineering of rivers in Japan. Though these were still engineering-​based solutions and fell short of holistic conservation that brings the river back to its original flow characteristics, these were significant actions that show pockets of successful fightbacks against the rampant deterioration of rivers in the post-​Second World War era. The present chapter captures this story of degradation and restoration in two Japanese River basins, the Kuma River in Kumamoto prefecture, and the Yahagi River in Nagano, Gifu, and Aichi Prefectures (Figure 9.1). Both river basins have experienced the full onslaught of urbanized basin developments such as channel modifications, dams, and physical and chemical pollution. The chapter shows pathways of degradation and associated landscape changes in the Kuma River basin and showcases a citizen movement that partly restored the dying Yahagi River basin. 9.2 Methods The case study of the Kuma River basin is based on three months of fieldwork by the first author of the chapter for three months in 2016. In the fieldwork, key informant interviews were carried out with local experts (leading fishers, farmers, businesspersons) whose livelihoods depend on the Kuma River and a professional environmental activist, together with direct observation and fieldnote taking. The interviewees were 50 years and above, and they had long-​term experience on the Kuma River and its changes. The qualitative design allowed the authors to navigate a longer time frame of about 30 years. The case study of the Yahagi River basin is based on a review of secondary literature with the authors’ own opinions based on their expertise on sustainable river basins and sustainable water resource management.

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Water ecosystem management in Japan: successes and failures  155

Figure 9.1 Location of the Kuma River and Yahagi River basins.

156  Urban Water Ecosystems in Africa and Asia 9.3  Case Studies 9.3.1  The Kuma River

The Kuma is a major river in central Kyushu in Japan. The river originates from Mt. Choushigasa (1489 m). At Hitoyoshi city, the Kuma River is joined by the Kawabe (62 km), another significant river that forms a major tributary of the Kuma. The Kuma River has 80 tributaries with a total length of 434 km. The upper course of the river is characterized by a steep gradient, which abruptly changes to a moderate slope at Hitoyoshi Plain. The river flows through a narrow valley downstream and finally branches off into a number of channels before pouring into Yatsushiro Bay. The rainfall characteristic is strongly influenced by the Asian monsoon climate, with heavy rainfall from June to September; most of the flooding also takes place during this time, mainly in the plainlands. The river is a good example of ecosystem connections exemplified by the migration of sweetfish locally known as Ayu (Plecoglossus altivelis). The fish migrate upriver in the Springtime for spawning. In fact, the river was noted for the diversity (43 types) of riverine fish species, together with mollusks and crustaceans (MLIT, 2013). The mudflat at Yatsushiro Bay formed by the sediment supply of the Kuma River, together with the coastal geomorphological processes is noted as one of the important bird areas in Japan (Wild Bird Society of Japan, n.d.). The Kuma River has been a vital source of livelihood and recreation for its basin society, which saw the degradation of the natural riverine environment over the last 50 years (Chakraborty and Chakraborty 2016). As a result of these degradations the watershed has attracted some well-​noted citizen protests in Japan, the most notable example is the successful decommissioning of the proposed dam over the Kawabe River (see: https://​kaw​abeg​awa.jp/​eng/​eng​top.html). Of late, the eco­ logical connection in the river basin has tried to be restored through the removal of the Arase dam, which started in 2012 and ended in March 2018. The removal of the dam has opened a vast expanse of the lower reach of the river basin to natural processes needed for a biodiverse and resource-​rich river basin. Below we describe how the riverine landscape diversity has changed over time due to development interventions before the removal of the Arase dam. (a) Direct changes in the river course: The earliest significant change that affected the river throughout its course was the removal of the large boulders to make the river more navigable for transport in the 17th Century (Maeyama, 1997), although not much of the ecological consequences can be tracked of the direct changes in the river course due to this change. But this was one of the first stages of river engineering that started to compromise the natural flow of the river. (b) Disappearance of the heterogeneous landscapes and increase of plantation forests: During the post-Second World War I, the river basin started to be influenced by heavy human influence. The climax vegetation types of beech (Fagus crenata) and varieties of evergreen oak (Quercus) dominated the landscape. The beech forests were especially considered to have limited fuelwood and Roundwood value due to the large water retention in their trunk and root systems. As a result, beech

Water ecosystem management in Japan: successes and failures  157 forests were felled after the post-​Second World War for the establishment of large-​ scale plantation forests. The disappearance of the natural forest ecosystem was a significant benchmark of landscape-​wide change that would follow. As far as agricultural land use is concerned, the river basin was characterized by the cultivation of barley, Japanese millet, azuki beans, sweet potatoes, chestnut, corn, dry rice, and taro, among others, through slash-​and-​burn agriculture up to the first half of 20th century. The small-​scale slash-​and-​burn agriculture was carried out in open woodlands with evergreen broadleaf forests of oak and beech (Miyawaki, 1984). This system of slash-​and-​burn agriculture gave way to coppice woodlands for extracting charcoal. The lowland areas of the basin were dominated by rice cultivation until the large-​scale urbanization in the 20th century. These diverse landscape mosaics that continued up to the 20th century (beech and oak forests, small-​scale wet rice, slash-​and-​burn agriculture, coppicing, management of rice paddies, upland forests, grasslands, and wetlands, and use of the riverine fisheries) were replaced by intensive wet rice cultivation and abandonment of the coppicing system with the advent of oil-​based energy use from the 1950s. These traditional agroecological landscape mosaics (better known as ‘Satoyama’ in Japan) denote landscapes that are multi-​functional and useful for extracting bundles of ecosystem services (Takeuchi, 2016; UN, 2013). The intensive wet rice cultivation was accompanied by the abandonment of slash-​and-​burn agriculture and an increase of coppice woodlands for charcoal extraction (Shiiba and Utsumi, 2010). The agroecological landscape of the river basin shifted drastically to planted forests of Japanese cedar and Japanese cypress trees from the 1940s. The river flow was used to transport logs from these forests to the paper, furniture, and construction industries downstream near Yatsushiro Bay. (c) Increase of dams, embankments, and irrigation canals in the watershed: The above-​mentioned landscape changes were also accompanied by changes in the river regime. During the 18th century, large-​scale irrigation canals were started to be built in the alluvial fan regions in the Hitoyoshi Plain. These flow diversions were accompanied by the concretization of beds and banks to arrest the water loss due to the porous soil of the Hitoyoshi plain (MLIT, 2006; Maeyama 1997). In the post-​war period, several major dams dominated the river landscape. The building of dams was primarily due to Japan’s dependence on hydroelectric power to fuel its economic growth and urban development (Michaud, 2015). Three dams, primarily for hydroelectricity and irrigation-​Ichifusa, Setoishi, and Arase, and two barrages –​ Yohai and Kumagawa significantly changed the flow regime of the river basin (see Figure 9.2). The dams and barrages were built to make the river basin floodproof while producing hydropower (from the dams) to support large infrastructure development. However, arguably, the dams increased flooding in some areas rather than decreased (Kumagawa Ryuiki Jumin Kikitori Chosa Hokoku Henshu Iinkai, 2008; Takahashi 2009). A notable example can be given of the 1965 incident of the Ichifusa Dam, which released a large volume of water causing floods downstream (Takahashi, 2009). These kinds of artificial flooding were a major root of the start of citizen protest movements that campaigned against the building of a dam on the Kawabe River. Similar sentiments also helped remove the Arase dam, the only

158  Urban Water Ecosystems in Africa and Asia

Figure 9.2 (a) Ichifusa Dam was established in 1959. (b) Setoishi Dam was established in 1958. (c) Arase Dam was established in 1954 and removed in 2018. (d) Yohai barrage that stops the annual sweetfish run (Arguably built in 1608). (Photograph by Shamik Chakraborty.)

example of major dam removal in Japan. However, in spite of decommissioning the building of the dam, development interventions in preparation for the dam building have continued to affect the Kawabe River system (see Figures 9.3 and 9.4). The major argument by the locals who protested against the dams was to change the basin mindset against floods by not seeing them as ‘hazards’ (suigai in Japanese) but as floods (kouzui in Japanese), a term that increasingly gained ground in the post-​dam society. Scholars also have argued for the change in our understanding of the connection of ecosystems with river floods (see also Poff, 2002; Talbot et al, 2018). The most notable example of the degradation of the river due to the building of dams and embankments is the disappearance of the iconic wild sweetfish (Plecoglossus altivelis) run. The sweetfish run (much like the wild salmon runs) is an example of a ‘pulsed’ system (perioding upriver and downriver movement of

Water ecosystem management in Japan: successes and failures  159

Figure 9.3 (a) Woody debris-vital component for biodiverse rivers-​taken out from the river as they can enter and damage the Setoishi dam. (b) Bulldozers await their turn to carry the woody debris and dispose of it elsewhere. (c) Perennial grass cover and formation of a ‘char’ land in the midstream of the Kuma River. These ‘char’ lands are part of the underwater riffle sequence of the river where fish used to come for foraging, and thus these charlands denote the local degradation of the riverine ecosystem. (d) A local elementary school on a raised platform beside the Kuma River main flow to cope with the raised water levels due to release from the dam during periods of heavy rain. (Photographs by Shamik Chakraborty.)

the sweetfish) that works with other components of the pulsed system such as periodic flooding, or periodic human use of the landscape to extract diverse ecosystem services from the river basin. After the building of Yohai barrage (arguably built in 1608) 9 km from the coast, the sweetfish were unable to enter the Kuma River from the Yatsushiro Bay. At present the Kuma River Fisheries Cooperative carries the sweetfish fingerlings upriver through trucks to mimic the wild sweetfish run and to support the local economy and lucrative sport fishing (Kuma River Fisheries Cooperative, n. d.). Like the sweetfish, some other riverine species such as fresh­ water eels (Anguilla japonica) (which spawned along the rocky banks of the riparian areas), goby (Amphidromous Rhinogobius) (which preferred sandy but clear river bottoms), decreased with the building of the dams and barrages. These species were affected by the building of the dams and barrages that retarded the river’s natural flow but also by the concretization of riverbanks due to road construction for

160  Urban Water Ecosystems in Africa and Asia

Figure 9.4 (a) Concrete rip-​raps in the land-​water interface region of the Kawabe River, which, according to local experts, were vital spawning grounds for fish like freshwater eels as it degrades the lateral connectivity of the river. (b) A concrete weir on one of the tributaries of the Kawabe River retarding the natural flow of sediments, and like dams, it degrades the longitudinal connectivity of the river. (c) A section of the Kawabe River where the dam was planned, the large concrete bridge in the background denotes the expected water level, which would have submerged the small bridge below it. (d) A section of the upstream of the Kawabe River where the dam was planned. These roads marked the expected pond level of the dam.

facilitating dam and barrage construction as well as transport along the river course (see also, Podda et al, 2022; Sumizaki et al. 2019). In the land area, the Japanese rice fish (Oryzias latipes) numbers dwindled as a result of the increasing use of chemical fertilizers and pesticides in the agricultural areas. The decrease of ricefish denotes the deterioration of the zone of aggradation. The interviews and literature review show how different ecosystem services have degraded and become non-​existent in the river basin. The patches of landscapes with broadleaved forests, slash-​and-​burn and wet rice cultivation, coppice woodlands, and generally unregulated overflow provided a number of key river landscape uses (that released a number of ecosystem services) such as hunting (in winter), fishing (in summer), gathering of plants and mushrooms, cultivation of crops, gathering of wood fuel (from coppicing), and roundwood

Water ecosystem management in Japan: successes and failures  161 (from small-​scale plantations), and recreation in the local landscapes. Larger woodlands and unregulated river flows were key components for these diverse uses of the landscape by the basin society. These activities became simplified with mainly the sweetfish-​based fishing industry, sport fishing, irrigation-​based wet rice cultivation, and hydroelectric energy acquisition for export in the northern Kyushu industrial belt. These changed and simplified ecosystem services also meant decreased resource self-​sufficiency in the river basin (Chakraborty and Chakraborty, 2016). Based on the foregoing, the case of socioecological changes in Kuma River represents a case of loss of landscape diversity which also relates to ecological connectivity in the river basin (see also Ward and Stanford 1995). The health of terrestrial and aquatic ecosystems depends on natural disturbance regimes, including flooding. The flow regulation schemes (dams, barrages, and concretization of beds and banks) tend to negatively impact such dynamic systems (Wohl, 2005). It is, therefore, necessary that we try to understand and make river basin policies abide by the natural landscape elements and (natural disturbance regimes such as flooding. Other scholars have also argued for the need of natural forests in the river and its flow through the urban areas (Bahar, 2008; Talbot et al. 2018). River restoration should also bring into the picture, the natural landscape processes that are fundamental for bringing back ecologically rooted riverine processes and their functions (Nagayama et al. 2009). In the case of Japan, its rivers have extensively experienced compromised functions such as flow regulations, flow diversions, straightening of channels, and concretization of river valleys), especially during the post-​Second World War economic growth. But these rivers have high species endemism (Yoshimura 2005), and for successful restoration of rivers it is needed that the basin society continues to consider the ecosystem connectivity in a river basin through better socio-​cultural appreciation (see also Haslam 2008). 9.3.2  The Yahagi River

The Yahagi is a 118 km long river running through Nagano, Gifu and Aichi Prefectures before draining into Mikawa Bay. The river basin showcases a unique case of river basin degradation due to Japan’s post-​war economic development and, subsequently, citizen protests and movements to restore the dying river. After the Second World War, Japan started to rebuild its economy without adequate environmental impact assessments and conservation measures. As a result, in many parts of the country water environments started to become contaminated with pollution. Some notable examples are the ‘itai-​itai’ disease in the Jintsu River in Toyama Prefecture due to cadmium pollution, and Minamata disease due to organic mercury pollution in the Minamata Bay (Kumamoto Prefecture) and Agano River (Niigata Prefecture). However, from this period of post-​war reconstruction, public opinions for better environmental regulation also started to gain ground (Otsuka et al., n.d.). In 1958, about 700 fishers from the Edo River basin area protested violently against the Honshu pulp company to stop

162  Urban Water Ecosystems in Africa and Asia injecting contaminated wastewater into the rivers of Tokyo Bay that jeopardized their fishing-​based livelihoods (Otsuka et al., n.d.). Several authors have argued that although environmental laws were put into effect, these laws were defective by not putting environmental conservation as the main priority (Otsuka et al., n.d.; Okada and Peterson, 2000). The Yahagi River basin became a prime example of two following types of river pollution which adversely affected downstream fisheries and agriculture: (1) In the upstream more than 150 gravel and silica mines operated that churned the upstream soil and water complex of the river to seek out only gravel and silica and send the remaining sediments as tailings downstream. About 1.26 million cubic meters of gravel were extracted per year (Hara, 1975). Hara (1975), in his study of water quality along 18 stations along the Yahagi River basin, notes an increase in pollution levels with the downstream flow of the river with a high amount of suspended sediments and chemical oxygen demand (COD). (2) Chemical pollution due to car manufacturing industries caused pollution of nitrogen to industrial and residential areas increased from the 1980s to 1990s in the middle to downstream reaches (Takeuchi et al., 2005). Following these pollution incidents and the massive loss of ecosystem-​based livelihoods including in the Mikawa Bay fisheries started a unique basin-​wide and (not government-​led but) bottom-​up citizens movement against river pollution and for sustainable use of river basin for ten years from 1960 to 1970 (Takahashi 2007). This initiative was so successful that later it was later recognized as ‘The Yahagi Method’. The countermeasure against river pollution took effect through several stages. First, the Meiji Canal Farmers’ Association together with six basin municipalities, seven fisheries groups and six agricultural organizations established the Yahagi River Coastal Water Quality Conservation Council (YWC). Second, the YWC monitored river water pollution by carrying out water quality surveys as well as facilities that caused water pollution in the river basin. Third, the actions of YWC were supported by the Yahagi River Basin Development Study Group, the Yahagi River Environmental Technology Study Group, and the Yahagi River Cleanup Association. These study groups and associations conducted awareness raising about river pollution and restoration, established water treatment technology, and monitoring and education activities in the development sites and facilities (JICA, 2022). The ‘Yahagi River method’ remains an example of citizen-​led protest and environmental restoration movement in Japan. We interpret this as a form of social-​ecological feedback involving citizen science that we need to understand more that has worked well with the conservation of the river. The successful cases can work well in general lesser understanding of deeper involvement, robust data, and against possible lack of action by decision-​makers on river basin restoration and management (see also Conrad and Hilchey, 2011; Aceves-​Bueno et al., 2017; Schölvinck et al., 2022; Collins et al. 2023).

Water ecosystem management in Japan: successes and failures  163 9.4  Concluding remark The two case studies show, first, that the awareness by the locals of the environmental repercussions of dam building in the Kuma River basin, and strong community stewardship for active river basin restoration, conservation, and monitoring for the Yahagi River basin show that reducing or stopping unsustainable river basin development and utilization is possible. The Kuma River case shows that conservation and restoration of the river basin has a unitary focus on removing dams, but the multifaceted consequences of the dam or the planning for the dam building can still continue to affect the river landscape and biodiversity. Although the Arase dam has been removed, the Kuma River-​Kawabe River system still lies in the heavy rainfall area of central Kyushu, and the river basin remains prone to flooding and, therefore, vulnerable to dam building in the future. Second, citizen science-​based restoration of the landscape has some major bottlenecks, such as the availability of limited and robust data, shallow involvement of the citizens for restoration, and lack of awareness and actions by decision-​ makers for restoration. The Yahagi River case shows that citizen science-​led methods of river basin restoration are a possible solution (in spite of bottlenecks) for river basin restoration; especially where top-​down government-​led efforts fall short due to technocentric regional development schemes (for both Kuma and Yahagi River basins) that followed as far back as from the 1940s. The river basin continues to be largely altered by the building of multiple dams, which continue to disrupt the natural sediment balance and flow regime of the lower reaches and the mudflat at Mikawa Bay. We would therefore like to conclude that although the restoration efforts were remarkable in their achievements, still, it is necessary to establish a multi-​species, and diverse ecosystem-​based conservation approach for river basins in Japan based on better lateral and longitudinal connectivity. Possible restoration points can be taken from the traditional agriculture, forestry, and wild (riverine) fisheries-​based land use to increase landscape diversity and biodiversity in human-​dominated river basins, including in urban areas. References Aceves-​Bueno, E., Adeleye, A. S., Feraud, M., Huang, Y., Tao, M., Yang, Y., et al. (2017). The accuracy of citizen science data: A quantitative review. The Bulletin of the Ecological Society of America, 98(4), 278–​290. http://​dx.doi.org/​10.1002/​bes2.1336 Bahar, M., Ohmori, H., & Yamamuro, M. (2008). Relationship between river water quality and land use in a small river basin running through the urbanizing area of central Japan. Limnology, 9, 19–​26. http://​dx.doi.org/​10.1007/​s10​201-​007-​0227-​z Chakraborty, A. (2013a). Opposing currents in a stream: Dichotomous trends of oost-​ growth basin governance in Japan’s Kizu River Basin. Asia Pacific World, 4(2), 81–​102. Accessed from: www.apu.ac.jp/​iaaps/​uplo​ads/​fckedi​tor/​apw/​vol4/​2_​6_​Op​posi​ng_​C​urre​ nts_​in_​a​_​Str​eam.pdf

164  Urban Water Ecosystems in Africa and Asia Chakraborty, A. (2013b). Developing Rivers: How Strong State and Bureaucracy Continue to Suffocate Environment-​Oriented River Governance in Japan. Sage Open, 3(4). https://​ doi.org/​10.1177/​21582​4401​3501​329 Chakraborty, S., & Chakraborty, A. (2016). Satoyama landscapes and their change in a River Basin context: Lessons for sustainability. Issues in Social Science, 5(1), 38–​64. Collins, R., France, A., Walker, M., & Browning, S. (2023). The potential for freshwater citizen science to engage and empower: A case study of the Rivers Trusts, United Kingdom. Frontiers in Environmental Science, 11, 1218055. https://​doi.org/​10.3389/​ fenvs.2023.1218​055 Conrad, C., & Hilchey, K. (2011). A review of citizen science and community-​based environmental monitoring: Issues and opportunities. Environmental Monitoring Assess. 176, 273–​291. http://​dx.doi.org/​10.1007/​s10​661-​010-​1582-​5 Haslam, S. M. (2008). The riverscapes and the river. Cambridge: Cambridge University Press. JICA (Japan International Cooperation Agency). (2022). Japan’s Experience on Water Resources Management. Accessed from www.ope​njic​arep​ort.jica.go.jp/​pdf/​100004​7169​ _​01.pdf Kuma River Fisheries Cooperative. (n.d.). Ayu no chigyo-​ chukan ikusei-​ houryu (Ayu fingerlings, intermediate breeding, discharge). Accessed from www.kumag​awa .or.jp/​ work.html Kumagawa Ryuiki Jumin Kikitori Chosa Hokoku Henshu Iinkai (Committee for Reporting on Residents Opinion Survey at Kuma River Basin). (2008). Damu ha suigai wo hikiokosu-​ Kumagawa Kawabegawa no suigai higaisha ha kataru (Dams cause floods: Residents of Kuma and Kawabe River basins voice their opinion). Tokyo: Kadensha. Maeyama, M. (1997). Kumagawa Monogatari (Tale of the Kuma River). Fukuoka: Ashishobo. Michaud, M. (2015). Dam Building and the Over-​Concretization of Japan. Kwansei Gakuin University Social Sciences Review Vol. 20. Nishinomiya, Japan. www.core.ac.uk/​downl​ oad/​pdf/​143638​585.pdf Miyawaki, A. (1984). A Vegetation ecological view of the Japanese archipelago. Bulletin of Institute of Environmental Science and Technology, Yokohama National University, 11, 85–​101. MLIT (Ministry of Land, Infrastructure, Transport and Tourism). (2006). Kumagawa suikei ryuiki oyobi kasen no youko (An overview of Kuma river and its watershed). Accessed from www.mlit.go.jp/​river/​shin​ngik​ai_​b​log/​sha​seis​hin/​kasenb​unka​kai/​sho​uiin​kai/​kih​ onho​ush in/​060810/​pdf/​ref6.pdf MLIT (Ministry of Land, Infrastructure, Transport and Tourism). (2013). Kumagawa karyuiki no kankyo saisei no arikata ni tsuite (Regarding pathways for environmental restoration in lower Kuma River basin). Committee for Lower Kuma Watershed Design. Accessed from www.qsr.mlit.go.jp/​yatus​iro/​sit​e_​fi​les/​file/​river/​utsuku​shi/​kanky​odes​ign /​ 04_​shiryo1.pdf Nagayama, S., Kawaguchi, Y., Nakano, D., & Nakamura, F. (2009). Summer microhabitat partitioning by different size classes of masu salmon (Oncorhynchus masou) in habitats formed by large wood in a large lowland river. Canadian Journal of Fisheries and Aquatic Sciences, 66(1), 42–​51. Okada, M., Peterson, S. A. (2000). Water pollution control policy and management. The Japanese experience. Gyosei. ISBN: 4324062404. https://​ndlsea​rch.ndl.go.jp/​books/​R10​ 0000​002-​I00000​3081​934

Water ecosystem management in Japan: successes and failures  165 Otsuka, K., Fujita, K., Isono Yoyoi, & Mizouchi, M. (n. d.) Governance for water environment conservation: Implications from Japanese experience. Chapter 4. Accessed from www.ide.go.jp/​libr​ary/​Engl​ish/​Publ​ish/​Repo​rts/​Jrp/​pdf/​153_​ch4.pdf Podda, C., Palmas, F., Pusceddu, A., & Sabatini, A. (2022). When the eel meets dams: larger dams’ long-term impacts on Anguilla anguilla (L., 1758). Frontiers in environmental Science, 10, 876369. Poff, N. L. (2002). Ecological response to and management of increased flooding caused by climate change. Philosophical Transactions of the Royal Society of London, 360, 1497–​1510. Schölvinck, A.-​F. M., Scholten, W., & Diederen, P. J. M. (2022). Improve water quality through meaningful, not just any, citizen science. PLOS Water, 1(12), e0000065. http://​ dx.doi.org/​10.1371/​jour​nal.pwat.0000​065 Shiiba, Y., & Utsumi, Y. (2010). Miyazaki ken shiba mura okawachi chiku ni okeru yakihata nogyo. (Slash and burn agricultural practices in Okawachi area, Shiiba village in Miyazaki Prefecture). Bulletin of Kyushu University Forestry Department, 91, 34–​39. Sumizaki, Y., Kawanishi, R., Inoue, M., Takagi, M., & Omori, K. (2019). Contrasting effects of dams with and without reservoirs on the population density of an amphidromous goby in southwestern Japan. Ichthyological Research, 66, 319–329. Takahasi, Y., & Juha I. U. (2004). Evolution of river management in Japan: From focus on economic benefits to a comprehensive view. Global Environmental Change 14(Supplement): 63–​70. Takahashi, Y. (2009). Kawabegawa damu wa iranai (Kawabegawa dam is not needed). Tokyo: Iwanami Shoten. Takahashi, S. (2007). The essence of the “Yahagi River method”, as seen in the Yahagi River Basin environmental movement. Japanese Journal of Limnology, 68, 1–​13. https://​doi. org/​10.3739/​riku​sui.68.1 Takahasi, Y., & Uitto, J. I. (2004). Evolution of river management in Japan: From focus on economic benefits to a comprehensive view. Global Environmental Change, 14, 63–​70. https://​doi.org/​10.1016/​j.gloenv​cha.2003.11.005 Takeuchi, K., Ichikawa, K., & Elmqvist, T. (2016). Satoyama landscape as social–​ecological system: Historical changes and future perspective. Current Opinion in Environmental Sustainability, 19, 30–​39. Takeuchi, M., Itahashi, S., & Saito, M. (2005). A water quality analysis system to evaluate the impact of agricultural activities on N outflow in river basins in Japan. Science in China Series C: Life Sciences, 48, 100–​109. Talbot, C. J., et al. (2018). The impact of flooding on aquatic ecosystem services. Biogeochemistry, 141, 439–​461. http://​dx.doi.org/​10.1007/​s10​533-​018-​0449-​7 Totman, C. (1998). The Green Archipelago: Forestry in pre-​industrial Japan. Athens, Ohio: Ohio University Press. Ui, J. (ed). (1992). Industrial Pollution in Japan. Tokyo: United Nations University Press. UN (2013), Satoyama-​ Satoumi Ecosystems and Human Well-​ Being: Socio-​ Ecological Production Landscapes of Japan, UN, New York, https://​doi.org/​10.18356/​5d7e4​936-​en Ward, J. V., & Stanford, J. A. (1995). The serial discontinuity concept: Extending the model to floodplain rivers. River Research Applications, 10(2-​4), 159–​168. http://​dx.doi.org/​ 10.1002/​rrr.345​0100​211 Wohl, E. (2005). Compromised rivers: Understanding historical human impacts on rivers in the context of restoration. Ecology and Society, 10(2), 2. Accessed from www.ecolog​yand​ soci​ety.org/​vol10/​iss2/​art2/​

166  Urban Water Ecosystems in Africa and Asia Wild Bird Society of Japan. (n. d.). Kumagawa estuary. Accessed from www.wbsj.org /​ nature/​hogo/​others/​iba/​eng/​146.html Yoshimura, C., Omura, T., Furumai, H., & Tockner, K. (2005). Present state of rivers and streams in Japan. River Research and Applications, 21(2-​3): 93–​112. http://​dx.doi.org/​ 10.1002/​rra.835

10 Building resilience to climate change through water retention solutions in Ca Mau City, Vietnam Huynh Vuong Thu Minh, Le Anh Tuan, Nguyen Dinh Giang Nam, Tran Van Ty, Kim Lavane, Pankaj Kumar, and Nigel K. Downes

10.1 Introduction The Vietnamese Mekong Delta (VMD) is characterized by intense agricultural production but also by rapid urbanization, particularly in its small and medium-​sized coastal cities. The region is listed as one of the most vulnerable localities to climate change (IPCC, 2014; Kuenzer et al., 2016). Increased precipitation and heavy rain­ fall events in the wet season, extended dry periods in the dry season, and sea-​level rise, compounded by socioeconomic development and recent land use changes, have resulted in more frequent and intense floods, droughts, and periods of freshwater scarcity. It is well understood that climate change and urbanization are closely interconnected. Cities are both drivers of climate change yet are particularly affected by its impacts (Bulkeley and Betsill 2005). The need for climate mitigation and adaptation is, therefore, becoming increasingly recognized by Vietnamese policymakers. Rapid urbanization in the VMD has led to increased surface sealing and associated flood events following heavy rainfall, loss of infiltration and retention areas generating higher runoff volumes and flood depths, increased water demands for both domestic and industrial needs, and increased exposure of population and assets through the expansion of settlements into flood-​prone areas (Garschagen, 2013, 2014; Radhakrishnan et al., 2018; Storch & Downes, 2011; Zevenbergen, Gersonius, & Radhakrishan, 2020). Contrary to other provinces in the VMD, Ca Mau is a coastal province that cannot supplement freshwater from the Mekong River upstream (Pham et al., 2023; Tri et al., 2023; Nhung et al., 2019). As a result, groundwater and rainfall are the only sources of freshwater for Ca Mau’s agricultural, industrial, and domestic sectors (Giusto et al., 2021; Nhung et al., 2019; Deb et al., 2016). The province has been badly damaged by both drought and saltwater intrusion because of rising climate anomalies and extreme weather events, which are further exacerbated by unsustainable groundwater exploitation (Wagner et al., 2012; Erban et al., 2014; DOI: 10.4324/9781003437833-10

168  Urban Water Ecosystems in Africa and Asia Shrestha et al., 2016; Minderhoud et al., 2017; Karlsrud et al., 2017; Baca & Nguyen, 2017). In Ca Mau, weather patterns and natural calamities have grown more intricate and unpredictable in recent years, threatening the economic basis and sustainability of the urban-​rural region. In this context, flexible, nature-​based, and hybrid solutions in urban and regional planning are gaining increasing importance. (Pistocchi et al., 2017; Qi et al., 2020; Sitzenfrei et al., 2020; Pânzaru et al., 2022). NBS refers to the sustainable management and use of nature for tackling environmental and societal issues such as climate change and the urban heat island effect, water supply security, water and air pollution, food security, human health, and disaster risk management. They encompass the advancement and extension of green-​blue infrastructure (GBI), a strategically planned network of natural and semi-​natural areas with other environmental features, crafted and executed a vast array of ecosystem services. GBI strategizing also helps diminish reliance on ‘gray’ (built) infrastructure that is usually more costly to construct and maintain (Alves et al., 2019, 2020; Monteiro et al., 2020 Jia & Zhang 2021). 10.2  Research approach and method 10.2.1  Study area

Ca Mau province is recognized as the southernmost part of Vietnam (Figure 10.1). The largest province in the VMD, with a total land area of 529.88 km2, its terrain is low-​lying with a typical elevation of only 0.5–​1 m above mean sea level. Surrounded by both the East Sea and the Gulf of Thailand, the coastline of the province is marked by pronounced mangrove squeeze and high erosion rates, while the inland water system is affected by salinity intrusion, freshwater scarcity during the dry season, and flooding during the wet season. Cape Ca Mau is where the Ca Mau province extends the farthest. This is the longest sea of the Ca Mau Peninsula’s alluvial, tidal, and projecting crest. Ca Mau Cape is located 100 kilometers from Ca Mau City, with coordinates of 8°34’ (or 8°30’) north and 104°40’ (or 104°50’) east. It is in the Dat Mui commune, Ngoc Hien district, and includes most of Xom Mui and a small portion of Rach Tau hamlet. Mui Ca Mau National Park is in Ca Mau Cape. Over 41,000 hectares of the Park’s territory are considered natural areas, of which 15,200 hectares are land and 26,600 hectares marine. Ca Mau Cape has developed over hundreds of years because of sea currents carrying alluvium, plankton, and nutrients from the Mekong River and the coastal waters of Soc Trang and Bac Lieu provinces. Many brackish-​tolerant plants have developed, in turn yielding hundreds of forest products, including mangroves, that are used as building materials, firewood, and medicines. Ca Mau Cape is also a source of services for intangible goods like research benefits, recreation, and tourism, literary, poetic, or artistic inspiration, as well as historical benefits. In terms of the environment, Cape Ca Mau is very important for maintaining water balance, controlling the climate,

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Source: Authors own.

Resilience to climate change–water retention solutions Ca Mau  169

Figure 10.1 Location of Ca Mau province and meteorological station.

170  Urban Water Ecosystems in Africa and Asia and reducing the negative consequences of natural disasters (Thoai et al., 2019). The International Coordinating Committee of the Man and Biosphere Program (MAB) designated Ca Mau Cape as a global biosphere reserve in 2009. Moreover in 2013, the Ngoc Hien district’s Mui Ca Mau National Park was named Vietnam’s sixth Ramsar site. According to Tuan (2013), the mangrove forest on the Ca Mau Peninsula is the largest in Vietnam. According to the Provincial Forest Protection Department of Ca Mau (2011), the province of Ca Mau had 109,085.4 hectares of forest and forestry land, comprising 40,911 ha of Melaleuca Forest, 67,553.9 ha of mangrove forest, and 620 ha of forest on islands. The ecosystem services of Mui Ca Mau are composed of all material and immaterial values but have as yet not been properly listed, quantified, and categorized based on their functions. 10.3  Study approaches A number of field surveys were conducted over the past three years in Ca Mau province to conduct key informant interviews stakeholder’s workshop household surveys and to gather opinions from all concerned groups. Simultaneously, secondary data such as governmental annual reports, future outlooks, and official planning documents were collected, and existing past meteorological and topographic data were analyzed. Moreover, an assessment of experiences and views on coping with drought and saline water intrusion risk in coastal areas in Ca Mau’s selected local communities was carried out. This included meetings with local government officers and consultations with comparatively vulnerable women and children. In community meetings as well as some targeted households in response to drought and salinity intrusion risks, different locally known techniques, and approaches to retain and access freshwater and views on the benefits of water retention methods and different adaptive livelihood models were carried out. 10.4  Results and discussion 10.4.1  Issues in Ca Mau Province 10.4.1.1  Natural hazard in Ca Mau

Minh et al. (2022) found that Ca Mau province exhibits more months of drought. Rainfall varies greatly in terms of season and intensity (Deb, Tran, & Udmale, 2016; Lee & Dang, 2020). The southwest monsoon is the main source of rainfall throughout the wet season, and its strength increases from May to October, with a peak in October. Several inundation events happened in Ca Mau City in recent years, including in 2006 (109 mm), 2008 (134.9 mm), 2014 (111.4 mm), 2015 (189.2 mm), and especially in 2019 (up to 212 mm), which have been identified in the Ca Mau Peninsula (Deb et al., 2016; Lee & Dang, 2020; Van et al., 2015). Minh et al., (2022) also found that Ca Mau province exhibits more months of drought

Resilience to climate change–water retention solutions Ca Mau  171

Figure 10.2 Occurrence frequency of various drought events at SPI 3 (a), SPI 6 (b), and SPI 9 (c) over 14 meteorological stations in the VMD. Source: Authors own.

onset, especially severe and moderate droughts, than the rest of the VMD provinces (Figure 10.2). Ca Mau can experience extreme drought in the dry season and extreme rainfall in the wet season. Although El Niño is responsible for most drought events, local weather disturbances (storms or local wind) also impact drought and wet events in the province.

172  Urban Water Ecosystems in Africa and Asia 10.4.1.2  Landslides along the sea dike in the west of Ca Mau

The area to the east of the Ca Mau peninsula has witnessed widespread erosion and landslides during the past 100 years (Nguyen et al., 2020; Marchesiello et al., 2019; Tamura et al., 2020). Aerial images of the shoreline over time demonstrated this change (Figure 10.3). The cause of landslides and subsidence in Ca Mau province is because of multiple factors related to both natural and social factors, including geographical conditions, topography, soil; meteorological and hydrological regimes; living and production practices; traffic density; investment in irrigation systems for water supply and drainage, etc. Particularly for the West Sea dike, the situation of landslides and subsidence is mainly caused by natural factors such as rain, wind, currents, waves, and drought. However, the accurate assessment and determination of causes and rules require careful research and calculation by scientists, institutes, and schools to draw accurate conclusions with a full scientific basis. Tables 10.1 and 10.2 present the locations and the situation of erosion and sedimentation in Ca Mau province that happened during 1995–​2016. Landslides affect up to 80% of Ca Mau´s coastline, over 80% of which exhibit a rate of up to 20 ÷ 25 m/​year, and in some places up to 50 m/​year. The West Coast alone has an area of 57,000 m length classified as at extreme risk of landslides. Due to coastal squeeze, the protective forest belt is less than 100 m in width in numerous locations, whereas other places no longer exhibit a protective forest, and waves often directly threaten the sea dike and other infrastructure (Phan & Stive 2022). In the west, the sea dike can be breached at any time, including the sections: (1) from Tieu Dua to Ba Tinh, 25,000 m long; (2) the section from Ba Tinh to Mui Tram, 17,000 m long; and (3) from Song Doc to Bay Hap estuary, 15,000 m long. Especially when the southwest monsoon is active, and the tide is high, the West Coast is directly threatened by the disappearance of the protective forest belt, for example, as in the West Sea dike erosion incident. On August 3, 2019, the risk directly affected 26,160 coastal households and 128,900 hectares of agricultural land. The drought in the dry season of 2019–​2020 appeared earlier than normal and at a more severe level, causing serious damage and seriously affecting production and people’s livelihood in the province. In particular, the drought has caused the channels and canals to dry up and lose water pressure, causing subsidence and serious landslides in over 1,600 localities along the West Sea dike and many major traffic routes, with a total length of over 25 km. Particularly, the West Sea dike had three major subsidence points, with a total length of 240 m, specifically: (1) The subsidence occurred on February 18, 2020, along the section of Da Bac toward New Canal (far from the tourist area). Hon Da Bac is about 300 m toward Kenh Moi) in Khanh Binh Tay commune, Tran Van Thoi district, with a length of about 120 m, depth from 1.2 m to 2 m, and subsidence almost the entire width of the dike; (2) The subsidence occurred on February 23, 2020, the section of Da Bac toward the New Canal (about 100 m from Hon Da Bac tourist area toward the New Canal, following the 120 m section that collapsed on the 18th of January). Also, in Khanh

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Resilience to climate change–water retention solutions Ca Mau  173

Figure 10.3 Historical evolution of the shorelines in Ca Mau coastal area from 1896 to 1991.

174  Urban Water Ecosystems in Africa and Asia Table 10.1 The trend of sedimentation -​erosion of estuaries of Ca Mau No

Location

Level

Trends of 1995-​2016

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

Tieu Dua Hương Mai Lung Ranh Khanh Hoi T29 Khai Hoang Ba Tinh Sao Luoi Đa Bac Kenh Moi Song Đoc My Binh Cai Cam Cai Đoi Vam Bay Hap Cua Lon Cai Moi Hai Thien Rach Mui

High damage High damage High damage Low damage Medium damage High damage High damage High damage High damage High damage Medium damage Low damage Low damage Accretion Accretion Accretion Accretion High damage High damage

Strong erosion >20 m/​year Moderate erosion 10 m/​year Strong erosion >20 m/​year Slight erosion of unprotected section Erosion 5–​10 m/​year Strong erosion > 20 m/​year Strong erosion 15–​20 m/​year Strong erosion 10–​15 m/​year Strong erosion Strong erosion 15–​20 m/​year Strong erosion in the North Riverside Local erosion in the North Riverside Local erosion in the North Riverside Stable Deposition evenly Deposition evenly Deposition evenly Strong erosion Strong erosion

Table 10.2 The trend of sedimentation -​erosion of shorelines of Ca Mau No

Location

Level

Trends of 1995-​2016

1 2 3 4 5 6 7

Tieu Dua -​Lung Ranh Lung Ranh -​T29 T29 -​Kenh Moi Kenh Moi -​Song Đoc Song Đoc -​Cai Đoi Vam Cai Đoi Vam -​Hai Thien Hai Thien -​Xom Mui

High damage Low damage High damage Low damage Accretion Strong accretion High damage

Strong erosion 5–​10 m/​year Low erosion 0–​5 m/​year Strong erosion 5–​20 m/​year Slight erosion 5-​10 m/​year Stable Extending 60–​100 m/​year Strong erosion 15–​20 m/​year

Binh Tay commune, Tran Van Thoi district, with a length of about 90 m, depth from 0.5 m to 2.2 m and subsidence of almost the entire width of the dike; (3) The subsidence occurred on March 19, 2020, the section of Kenh Moi toward Da Bac (about 800 m from Kenh Moi sluice), in Khanh Binh Tay commune, Tran Van Thoi district, with a length of about 30 m, from 0.08 m to 0.1 m deep toward the sea. In addition, through the inspection and survey of the West Sea dike line, the section from Vam Kenh Moi to Vam Da Bac, with a length of over 4,200 m, there are signs of cracks and a very high risk of subsidence. Causes: The cause of landslides and subsidence in Ca Mau province is because of numerous factors related to both natural and social such as geographical conditions, topography, soil, meteorological and hydrological regimes, living and production practices, traffic density,

Resilience to climate change–water retention solutions Ca Mau  175 investment in irrigation systems for water supply and drainage. Particularly for the West Sea dike, the situation of landslides and subsidence is mainly caused by natural factors such as rain, wind, currents, waves, and drought. However, the accurate assessment and determination of causes and rules require careful research and calculation by scientists, institutes, and schools to draw accurate conclusions with a full scientific basis. 10.4.1.3  Local inundation in Ca Mau City

Currently, the drainage system of Ca Mau City is composed of combined sewer and stormwater drainage. In Ca Mau City, the main drainage systems, including pipeline systems, are interconnected as follows: (i) Ganh Hao River is an important river axis with a large width, connecting the flow through Ca Mau City to the East Sea; (ii) Ong Doc River connects to the West Sea; (iii) Ca Mau -​Bac Lieu Canal is a source of water supply, drainage, and navigation connecting Ca Mau and Bac Lieu, and finally to the East Sea; and (iv) Quan Lo -​Phung Hiep Canal is formed from the Ca Mau Peninsula, leading water from Hau River, through Hau Giang region to Ca Mau City in the Northwest -​Southeast direction. Furthermore, rivers, canals, low-​lying ground, and ponds in nearby areas all provide useful drainage capacity for the city. Because the city lacks a wastewater treatment system, most used water is discharged into the water supply without being treated. Ca Mau City’s drainage system is being planned out to 2025, with the condition system covering over 80% of the urban area. Because of the increased urbanization density, the current drainage system in Ca Mau is rather old, and slow to upgrade, and the ground subsidence in Ca Mau is quite high, so the ability to drain urban water is slow when there is a problem. Because of heavy rain, numerous roads and residential areas are often flooded locally, especially when there is heavy rain over 50 mm during 3 hours. 10.5  Proposing solution for Ca Mau City 10.5.1  Maintaining ecosystem services for Ca Mau in the context of climate change

The importance of maintaining and safeguarding existing ecosystem services should not be overlooked. There are currently multiple actors involved, as well as intricate legal and institutional relationships in the use and provision of ecosystem services in Ca Mau. Communities, one or more levels of government, and occasionally NGOs, scientists, and companies are all engaged. These players may have quite varied viewpoints on the ecosystems that are being used and maintained, as well as the services they offer, particularly cultural services. While it is not appropriate or valid to generalize across the diverse combinations of governments, communities, forms of business, science, and states in the Oceania and Asia-​Pacific region, local peoples in many places hold knowledge, beliefs, and traditional practices that their governments may or may not understand or respect. Table 10.3

newgenrtpdf

Ecosystem Resources

Services Provided

Mangroves (fish, mangrove, tiger, parrot)

-​ -​ -​ -​

Sources of seafood (fish, shrimp, crab, oyster, snail)

-​ -​ -​ -​

Wild animals -​ (snake, turtle, otter, -​ bird, monkey, honey -​ bee) Soil and water in coastal mangroves

Source: Authors own

Air Conditioning Service

Construction materials Fuel (firewood, coal) Medicines Mangrove resin can be used in the processing of varnishes, paints, and printing inks

-​ Absorb carbon and pollutants, reduce greenhouse effect -​ Water filtration -​ Prevent storms, tornadoes -​ Air conditioning, humidity -​ Limiting saline intrusion inland -​ Ecological balance Food for humans -​ Water purification, partial Animal feed removal of water pollution Medicines -​ Ecological balance Sources of seeds and genes -​ Soil structure for aquaculture Food for humans -​ Ecological balance Medicines -​ Soil structure Genetic resources

-​ Place of residence -​ Cultivated land -​ Supply fresh water from rain, groundwater

-​ Climate control -​ Conserve water and land resources -​ Ecological balance

Support Services

Cultural Services

-​ Nutrient cycle -​ Seed Dispersal -​ Trap alluvium, expand the alluvial area -​ Anti-​erosion -​ Breeding ground for aquatic species and birds -​ Shelter for wild animals -​ Food source for other species -​ Nutrient cycle Gene Reserves -​ Organic decomposition -​ Food source for other species -​ Gene reserves -​ Help pollinate flowers -​ Seed dispersal -​ Land improvement -​ Forest fire fighting -​ Shelter for wild animals

-​ -​ -​ -​ -​

Scientific research Cultural sensibility Historical value Ecotourism, landscape Create jobs for people

-​ Scientific research -​ Cultural sensibility -​ Create jobs for people -​ Scientific research -​ Cultural sensibility -​ Create jobs for people -​ Historical value -​ Cultural sensibility -​ Create jobs for people

176  Urban Water Ecosystems in Africa and Asia

Table 10.3 List of ecosystem services of Ca Mau Cape

Resilience to climate change–water retention solutions Ca Mau  177 gives a list of ecosystem services in the Cape Ca Mau area. Ca Mau Cape is also under pressure from the people who exploit and destroy mangroves indiscriminately to raise shrimp (Tuan 2013). The specific techniques and activities are required to maintain the operation of the priceless mangrove environment in Ca Mau despite the adverse effects of climate change, including: -​ Take stock of and evaluate the diversity of plant and animal species in the Ca Mau region. -​ Create a plan to protect the uncommon and intertidal zone-​specific genetic resources of plants and animals. Mangrove ecosystem biodiversity must be preserved. -​ Decide on acceptable locations and efficient restoration techniques to prepare for mangrove restoration and replanting. -​ Integrating ecosystem services into decision-​making based on scientific evaluation techniques in order to manage and exploit natural resources sustainably. -​ Evaluate the threat and implement solutions to minimize coastal erosion and uncontrolled groundwater extraction in the area. 10.6  Ca Mau City requires the construction of a drainage system General view on surface water drainage in Ca Mau City The planned goal is to connect Ca Mau City’s surface water drainage system in order to ensure fast and reasonable water drainage and to reduce flooding within the city following unusually heavy rain. -​ Climate change elements such as abnormally strong rainfall spanning several days, and high tide must be factored into the relationship of regional river flows. -​ Areas with a high population density and a concentration of administrative, economic, cultural, and social activity should be prioritized for investment in drainage systems to reduce flooding duration. -​ Apply the principle of combining three solutions ‘Spreading water-​ Percolating water-​Draining water’ to the problem of delta urban drainage planning; Spreading water means discharging native or imported water to a permeable area to allow it to percolate to the zone of saturation and enter the groundwater. -​ Use natural low-​lying areas, rivers, and lakes extensively for water drainage. -​ Develop more regulating reservoirs or enlarge and deepen reservoirs, dredging natural river systems around and in urban areas to limit the quantity of water causing flooding. -​ Coordinate the design of urban landscapes, create parks and trees around the regulating lake, and build a local water treatment system on-​site, forming green urban areas. Clearing houses and works on rivers, canals, ponds, and lakes that obstruct the drainage system.

178  Urban Water Ecosystems in Africa and Asia Issues to consider for drainage system planning -​ It is vital to indicate the recent flood history (inundation location, timing, depth, causes of flooding, rainfall volume, and tidal elevation at the time of flooding) explicitly. Examine the causes of flooding in further depth: is it important to distinguish if flooding is caused by rain or by tides? Please specify the volume of rain that will cause flooding in the city (20%, 30%, 50%, 75%, 100%) or how high the water level will be. How does the sewer height relate to the tide level? -​ Division of drainage basins: It is critical to assess if the drainage direction comes from the City Construction Plan proposal or the consulting firm doing the drainage design. -​ There are currently several unoccupied fields, ponds, and lakes in and around Ca Mau City, including Ward 5, Ward 6, Ward 7, Ward 8, Ward 9, Ward Tan Xuyen and Tan Thanh Ward, and the suburbs. -​ Dredging of lakes and ponds will be combined with the creation of landscapes and natural areas to boost the value of nearby land—​reservoirs for non-​reducing air conditioning. -​ It is also used to store water during the dry season, so improving the local micro-​ climate and allowing for urban greening and firefighting efforts. If the room is large enough, this location can be used for cultural activities, entertainment, and leisure. -​ Besides building dikes and sewers, drainage design must cooperate with the renovation of sidewalks, public parking lots, squares, and factories to create absorbent spaces. Natural water, such as using bricks with holes to drain on sand or having lawns. Use of hard and soft solutions in Ca Mau The landslides can break the West Sea dike and will directly affect 26,160 coastal households and 128,900 hectares of agricultural land. Faced with the above urgent situation, right from the afternoon of August 3, 2019, the Provincial People’s Committee, the Provincial Steering Committee for Natural Disaster Prevention and Control and Search and Rescue have directed functional sectors, members of the Steering Committee to The provincial commander of natural disaster prevention and control and search and rescue coordinated with the local government to mobilize about 200 forces, 01 hoe, tools and supplies for dike protection under the motto 04 on the spot, immediately deploying the emergency dike protection measures to protect the dike and to be on duty day and night at the scene. 10.7  Conclusion and recommendations Water is not only a source of life but also an important factor for the building processes in the Mekong Delta, especially in coastal provinces like Ca Mau province. As the biggest wetland area of the region, VMD has received annually a high volume of flood water in the wet seasons from the upstream Mekong River.

Resilience to climate change–water retention solutions Ca Mau  179 Regionally, the over-​riverbank flooding water flows and stores mostly in the deep flood areas in the Plain of Reeds and the Long Xuyen Quadrangle, playing a key role in the hydrological, ecological, and environmental balance of the delta system. However, the Ca Mau peninsula is not part of the Mekong’s drainage area, so it is much more saline than the rest of the delta. Ca Mau province does not receive river water directly from the Hau River but has to go through a canal system, which is the Quan Lo -​Phung Hiep Canal. Numerous records of hydrological data have shown that the coastal zone is experiencing serious drought combined with saline water intrusion, as well as land subsidence that results from unsustainable groundwater extraction and reduced sedimentation. In the dry seasons of 2015 and 2016, the historical droughts hit the delta, especially in the coastal areas, as an impact of climate change and the El Niño phenomenon led to a significant freshwater shortage risks and deeper saline intrusion damages because of freshwater retention measures are inadequate. The development intensity-​ duration-​ frequency curve and drought index assessments contribute to an improved understanding of how unpredictable rainfall and meteorological anomaly conditions are in Ca Mau. The drought indices are described by assessing severity levels and identifying the beginning and ending of droughts. The findings of our study are highly valuable in providing policy-​ relevant information regarding extreme climate events and their impacts on water resources and for reducing inundation in Ca Mau City. Ca Mau City and other Mekong Delta cities have recently experienced subsidence because of the decline in sediment and the exploitation of subsurface water. While the phenomenon of ground subsidence because of the consolidation of young sediments is also occurring, this is not fully compensated by upstream sediment transport volumes. The exploitation of underground water, sand mining, and the increasing speed of urbanization are the causes that promote rapid ground subsidence. In order to solve the water retention issues in Ca Mau, a combination of hard and soft measures is required. With the city’s abundance of vacant land, making room for water is a viable option. In-​depth discussions with water and environmental experts, suggested that increasing the area and volume of local water storage for coastal areas is important in alleviating water stress during periods of drought, salinity, and landslides in the dry season and limiting flooding in the rainy season. A range of short-​medium to long-​term solutions regarding increased water retention capacity in the upper and middle zones to direct flood water to the coastal zones, partly to reduce saline intrusion and restrict groundwater use as a part of climate change adaptation strategy, is essential. The merged findings from the community meetings and interviews with the findings from the literature suggest solutions for freshwater storage and the development and rollout of drought and salinity-​adapted livelihood models for resource-​ poor farmers. These are needed to integrate combination water retention options such as rainwater harvesting, river flood storage in low-​lying areas or canals, underground storage, and treating salt and brackish water.

180  Urban Water Ecosystems in Africa and Asia References Alves, A., Gersonius, B., Kapelan, Z., Vojinovic, Z., & Sanchez, A. (2019). Assessing the Co-​benefits of green-​blue-​grey infrastructure for sustainable urban flood risk management. Journal of Environmental Management, 239, 244–​254. Alves, A., Vojinovic, Z., Kapelan, Z., Sanchez, A., & Gersonius, B. (2020). Exploring trade-​ offs among the multiple benefits of green-​blue-​grey infrastructure for urban flood mitigation. Science of the Total Environment, 703, 134980. Baca, A. C. & Nguyen, D. H. (2017). Toward integrated disaster risk management in Vietnam : recommendations based on the drought and saltwater intrusion crisis and the case for investing in longer-​term resilience (English). Washington, D.C.: World Bank Group. http://​docume​nts.worldb​ank.org/​cura​ted/​en/​751​7815​0996​6367​921/​Tow​ard-​int​ egra​ted-​disas​ter-​risk-​man​agem​ent-​in-​Viet​nam-​reco​mmen​dati​ons-​based-​on-​the-​drou​ght-​ and-​saltwa​ter-​intrus​ion-​cri​sis-​and-​the-​case-​for-​invest​ing-​in-​lon​ger-​term-​res​ilie​nce Deb, P., Tran, Bulkeley, Harriet, & Michele Merrill Betsill. (2005). Cities and Climate Change: Urban Sustainability and Global Environmental Governance. Vol. 4. Psychology Press. Deb, P., Tran, D. A., & Udmale, P. D. (2016). Assessment of the impacts of climate change and brackish irrigation water on rice productivity and evaluation of adaptation measures in Ca Mau province, Vietnam. Theoretical and Applied Climatology, 125(3–​ 4), 641–​656. Erban, L. E., Gorelick, S. M., & Zebker, H. A. (2014). Groundwater extraction, land subsidence, and sea-​level rise in the Mekong Delta, Vietnam. Environmental Research Letters, 9(8), 084010. Garschagen, M. (2013). Resilience and organisational institutionalism from a cross-​cultural perspective: An exploration based on urban climate change adaptation in Vietnam. Natural Hazards, 67(1), 25–​46. doi:10.1007/​s11069-​011-​9753-​4 Garschagen, M. (2014). Risky change?: Vulnerability and adaptation between climate change and transformation dynamics in Can Tho City, Vietnam, vol. 15. BiblioScout, 2014. doi: 10.25162/​9783515108812. Giusto, B. D., Le, T. M. N., Nguyen, T. T. M., Nguyen, T. T. H., Vu, N. U. M., & Lavallee, J. P. (2021). Development versus adaptation? Facing climate change in Ca Mau, Vietnam. Atmosphere, 12(9), 1160. IPCC. (2014). Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland, 151 pp. Retrieved from www.ipcc.ch/​rep​ort/​ar5/​syr/​ Jia, J., & Zhang, X. (2021). A human-​scale investigation into economic benefits of urban green and blue infrastructure based on big data and machine learning: A case study of Wuhan. Journal of Cleaner Production, 316, 128321. Kuenzer, C., Moder, F., Jaspersen, V., Ahrens, M., Fabritius, M., Funkenberg, T., …Dech, S. (2016). A Water Related Information System for the Sustainable Development of the Mekong Delta: Experiences of the German-​ Vietnamese WISDOM Project. In D. Borchardt, J. J. Bogardi, & R. B. Ibisch (Eds.), Integrated Water Resources Management: Concept, Research and Implementation (pp. 377–​412). Cham: Springer International Publishing. Karlsrud, K., Vangelsten, B. V., & Frauenfelder, R. (2017). Subsidence and shoreline retreat in the Ca Mau Province–​Vietnam. Causes, consequences and mitigation options. Geotechnical Journal of the SEAGS & AGSSEA, 48, 26–​32.

Resilience to climate change–water retention solutions Ca Mau  181 Lee, S. K., & Dang, T. A. (2020). Extreme rainfall trends over the Mekong Delta under the impacts of climate change. International Journal of Climate Change Strategies and Management, 12(5), 639–​652. doi:10.1108/​IJCCSM-​04-​2020-​0032 Marchesiello, P., Nguyen, N. M., Gratiot, N., Loisel, H., Anthony, E. J., San Dinh, C., ... & Kestenare, E. (2019). Erosion of the coastal Mekong delta: Assessing natural against man induced processes. Continental Shelf Research, 181, 72–​89. Minderhoud, P. S., Erkens, G., Pham, V. H., Bui, V. T., Erban, L., Kooi, H., & Stouthamer, E. (2017). Impacts of 25 years of groundwater extraction on subsidence in the Mekong delta, Vietnam. Environmental Research Letters, 12(6), 064006. Minh, H. V. T., Kumar, P., Van Ty, T., Duy, D. V., Han, T. G., Lavane, K., & Avtar, R. (2022). Understanding dry and wet conditions in the Vietnamese Mekong Delta using multiple drought indices: A case study in Ca Mau Province. Hydrology, 9(12), 213. Monteiro, R., Ferreira, J. C., & Antunes, P. (2020). Green infrastructure planning principles: An integrated literature review. Land, 9(12), 525. Nguyen, L. T. M., Hoang, H. T., Ta, H. V., & Park, P. S. (2020). Comparison of mangrove stand development on accretion and erosion sites in Ca Mau, Vietnam. Forests, 11(6), 615. Nhung, T. T., Le Vo, P., Van Nghi, V., & Bang, H. Q. (2019). Salt intrusion adaptation measures for sustainable agricultural development under climate change effects: A case of Ca Mau Peninsula, Vietnam. Climate Risk Management, 23, 88–​100. Pânzaru, D. M. R., Iojă, I. C., Pleșoianu, A. I., Hossu, C. A., & Diaconu, D. C. (2022). Nature-​based solutions for urban waters in Romanian cities. Nature-​Based Solutions, 2, 100036. Phan, M. H., & Stive, M. J. (2022). Managing mangroves and coastal land cover in the Mekong Delta. Ocean & Coastal Management, 219, 106013. Pham, V. C., Bauer, J., Börsig, N., Ho, J., Huu, L. V., Viet, H. T., ... & Norra, S. (2023). Groundwater use habits and environmental awareness in Ca Mau Province, Vietnam: Implications for sustainable water resource management. Environmental Challenges, 13, 100742. Pistocchi, A., Grizzetti, B., Zalewski, M., Gawlik, B., & Bidoglio, G. (2017). Nature-​based solutions for urban water management. Publications Office of the European Union. Qi, Y., Chan, F. K. S., Thorne, C., O’Donnell, E., Quagliolo, C., Comino, E., ... & Feng, M. (2020). Addressing challenges of urban water management in Chinese sponge cities via nature-​based solutions. Water, 12(10), 2788. Radhakrishnan, M., Nguyen, H. Q., Gersonius, B., Pathirana, A., Vinh, K. Q., Ashley, R. M., & Zevenbergen, C. (2018). Coping capacities for improving adaptation pathways for flood protection in Can Tho, Vietnam. Climatic Change, 149(1), 29–​41. doi:10.1007/​ s10584-​017-​1999-​8 Shrestha, S., Bach, T. V., & Pandey, V. P. (2016). Climate change impacts on groundwater resources in Mekong Delta under representative concentration pathways (RCPs) scenarios. Environmental Science & Policy, 61, 1–​13. Sitzenfrei, R., Kleidorfer, M., Bach, P. M., & Bacchin, T. K. (2020). Green infrastructures for urban water system: Balance between cities and nature. Water, 12(5), 1456. Storch, H., & Downes, N. K. (2011). A scenario-​based approach to assess Ho Chi Minh City’s urban development strategies against the impact of climate change. Cities, 28(6), 517–​526. doi:10.1016/​j.cities.2011.07.002 Tamura, T., Nguyen, V. L., Ta, T. K. O., Bateman, M. D., Gugliotta, M., Anthony, E. J., ... & Saito, Y. (2020). Long-​term sediment decline causes ongoing shrinkage of the Mekong megadelta, Vietnam. Scientific Reports, 10(1), 8085.

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11 Quantification of ecosystem benefits of community plantation and its impacts on human well-​being A case study from Kenya Pankaj Kumar, Tomoki Yagasaki, Gowhar Meraj, Shamik Chakraborty, Rajarshi Dasgupta, Amit Chatterjee, Huynh Vuong Thu Minh, Binaya Kumar Mishra, Ram Avtar, Osamu Saito, and Kazuhiko Takeuchi 11.1 Introduction Ecosystem services are all the tangible and nontangible benefits that people obtain directly or indirectly from ecosystems (Millennium Ecosystem Assessment 2005). Different ecosystem services, which form the foundation of human well-​being, depend on the structure, process, and function of the surrounding natural ecosystem (Zhang et al. 2015). Urbanization, being a major driver of land use and land cover changes every so often, has irreparable effects on the provision of ecosystem services around the globe (Eigenbrod et al. 2011; Ferreira et al. 2018; Kumar, 2019). However, to quantify the relationship between urbanization and ecosystem services, we not only need to know the characteristics of the study area but also need to decide the types of ecosystem services we are looking for and the indicators to measure urbanization level (Wang et al. 2019). On the other hand, the afforestation rate is exceeding the deforestation rate around the globe resulting in ‘forest transition’. Also, the types of ecosystem services or ecological attributes we can expect from this forest recovery depend on the types of forest transition (tree plantation, spontaneous regeneration, and agroforestry transitions) and social drivers to bring these transitions (Wilson et al. 2017). Despite widespread awareness of the nature and extent of multiple impacts of land-​use changes, there remains limited understanding of how these impacts affect trade-​offs among ecosystem services and their beneficiaries across spatial scales. Although afforestation and natural regeneration provide multiple benefits to nature and human societies and can play a major role in global and national restoration targets, however, these benefits are context-​specific and impacted by both biophysical and socioeconomic heterogeneity across landscapes (Sansevero et al. 2016). It is reported that afforestation as an adaptation strategy for managing land use change and human well-​being provided great results in terms of reducing risk from natural hazards as well as generating co-​benefits with the supply of multiple ecosystem services, namely habitat quality DOI: 10.4324/9781003437833-11

184  Urban Water Ecosystems in Africa and Asia improvement, regulatory services, ecological services, etc. (Sansevero et al. 2016; Fedele et al. 2018). It is found that species richness or habitat quality and number of ecosystem services is way higher in the case of mixed planted forests than monoculture forests (Leverkus and Castro 2017). Considering urban expansion and its impact on ecosystem degradation, forest plantations are expected to play a vital role in achieving recently adopted, global restoration targets such as the Bonn Challenge (to restore 150 million ha of degraded and deforested land by 2020) and the New York Declaration on Forests as well as the objectives of Article 5 of the Paris Climate Change Agreement. As a result, different afforestation initiatives started around the globe (Baral, Guariguata, and Keenan 2016). The Reducing Emissions from Deforestation and Forest Degradation Program (REDD+​), is one of the best-​known initiatives by the international communities to create a global forest governance system around the globe, which would impact countries on national, regional, and even local scales (Sunderlin et al. 2016). With different global afforestation initiatives, plantation area distribution among Asia, Europe, North and Central America, South America, Africa, and Oceania accounts for 62, 17, 9, 6, 4, and 42%) of the land area of China and encompasses almost all of the country’s arid and semiarid land areas. The central government of China invested 23 billion dollars into the TNAP between 1979 and 2008 in the hopes that the construction of this ‘Great Green Wall’ would greatly improve the environment in China’s ‘Three-​ North’ regions (i.e., Northeast, Northwest, and North Central) (Zhu et al. 2017). Although, at the global scale, the area of afforestation in Africa is not that significant, one of the major afforestation initiatives led by local communities called the Green Belt Movement (GBM) in Kenya started in the 1970s. Triggered by extreme deforestation, malnutrition, and employment, this project led by late Prof Wangari Mathaai (Nobel Peace Prize winner for her contributions to sustainable development, democracy, and peace) aims for not only afforestation at a very large scale but also women empowerment through employment and social justice (Hunt 2014). The GBM is best known for planting belts of trees, but it has developed many other projects as well including protecting public land, improving household food security, civic education, income-​generating activities, and improved cookstoves for lesser air pollution from household activities. This is a community engagement, where they should also know why they should stand for their rights. It is not about only planting trees but it is about the planting of ideas. More than 51 million trees have been planted on water towers i.e. mountains to receive significant rainfalls, farms, around schools and churches and hospitals, along roads and rivers, and in the countryside. Now 6% of Kenya’s land is forested, compared to 2% in 1978 (greenbeltmovement.org, Bioneers 2015, Green Belt Movement, GBM, 2016). Through this movement, Wangari Maathai was determined to stop land grabbing and illegal woodlog trading, even at the cost of shedding their own blood. The

Ecosystem benefits of community plantation in Kenya  185 best-​known cases are Uhuru Park and Karura Forest one of the examples of urban parks in Nairobi City under this scheme. The Kenya Forest Service and Friends of Karura Forest jointly developed management plans for Karura Forest that allowed only an administrative office at the gate, a visitor’s information center, and a café (Graydon 2005, MacDonald 2005, greenbeltmovement.org). To manage this initiative in the long run, there is a need for robust policy and management plans well supported by credible scientific information. However, at present, not much scientific information is available to indicate the true evaluation of these afforestation plans and their impacts on ecosystem services and human well-​being. Furthermore, the contributions of artificial forests (i.e., exotic plantations) in the Karura Forest Reserve are also still unclear. With the aforementioned knowledge gap, this research work focuses on a pilot study for the long-​term efforts to establish planted forests for the benefit of nearby residents in Nairobi, Kenya. We deal specifically with Karura Forest Reserve. This forest reserve has a long history of continuous efforts to preserve the forest areas by the Green Belt Movement (GBM) founded by Professor Wangari Maathai in 1977 (GBM 2016). It is currently managed by the Kenya Forest Service (KFS) in partnership with the Friends of Karura Forest (FKF), a community forest association. Their management plan for the Karura Forest Reserve includes the replacement of degraded and dying exotic tree plantations and the enrichment of degraded areas of indigenous forest by planting suitable indigenous species (Mariotte 2018). The forest vegetation, excluding plantations of Karura Forest Reserve, was surveyed and described by a primary study (Hayashi et al. 2006), which identified trees that are indigenous to the area. Little is known about the benefits obtained from the planted indigenous forests by local inhabitants. The utility of plant species is strongly dependent on the situations and growth conditions of the target vegetation. Thus, multiple efforts to document their contributions to residents’ well-​being are required. More precisely, the objective of this pilot study was: 1. To quantify various ecosystem services (carbon capture, habitat quality, seasonal water yield, water quality), their synergies and trade-​offs, and integrated human well-​being from the Kenyan Greenbelt movement: A case study of planted forest in Karura Forest within proximity to urban Nairobi, Kenya. 2. The way forward is about how to strengthen the linkages between humans (including their knowledge) and ecosystem services, which would greatly benefit people worldwide. 11.2  Material and methods 11.2.1  Study site

The Karura Forest Reserve (Office: 1°14’48.7“S, 36°49’00.4”E) is located in the north of Nairobi City (Figure 11.1). Its altitude ranges between 1,640m and 1,740m) and it covers an area of 1041.3 ha. Almost all of the reserve lies within

186  Urban Water Ecosystems in Africa and Asia

Figure 11.1 Map of study area showing Karura Forest Reserve.

a zone of Afromontane dry transitional forest as one of the types of potential natural vegetation on the drier lower slopes of East African mountains and uplands, which rise from the plains covered with Somalia-​Masai bushlands (van Breugel et al. 2015). The reserve has exotic and indigenous plantations that cover 461 ha (44 percent of the reserve area) and 257 ha (25 percent), respectively (KFS & FKF 2016). The first experimental plantations in Karura were planted in 1906, using various species of Eucalyptus and Cypress (KFS and FKF 2016). In Karura Forest, large remnants of Brachylaena-​Croton forest, a type of indigenous semi-​ deciduous forest, were preserved (Verdcourt 1962). These forests occurred mainly on plateaus with an annual rainfall of 875–​1,000mm, dominated by Brachylaena huillensis (synonym: Brachylaena hutchinsii), and Croton megalocarpus (Lind and Morrison 1974). The composition of semi-​deciduous forests in the Karura Forest was surveyed by Kigmo et al. (1990). The most abundant tree species in the Karura Forest is Eucalyptus paniculata (Nyambane et al. 2016). The reserve is now in existence through a long history of continuous efforts by many stakeholders for the preservation of the forest areas with preventing deforestation for at least several decades (Maathai 2006a, 2006b; Njeru 2010). The forest became a Central Government Forest Reserve in 1964 through Legal Notice 174 (KFS & FKF 2016). According to the Forests Act in Kenya, every state forest, local authority forest, and provisional forest shall be managed in accordance with a management plan that complies with the requirements prescribed by rules made under the Act (Republic of Kenya 2005). The Karura Forest Reserve is a prime example of a well-​designed and successfully implemented strategic management plan. The dense population surrounding the Karura Forest Reserve, including two

Ecosystem benefits of community plantation in Kenya  187 informal settlements and several more affluent areas, has led to high demands on forest resources (KFS & FKF 2016). The Karura Forest is surrounded by communities of very different extreme socioeconomic statuses comprising both affluent and economically deprived communities, where later community members benefit in different ways ranging from employment, food, fuel, etc., by participatory forest management activities (KFS and FKF 2016). 11.2.2  Data collection

The methodology for data collection is shown in Figure 11.2. We conducted a ques­ tionnaire survey in the Karura Forest Reserve in March 2019. We chose beneficiaries of the forest as target respondents (n=​56) and collected information on the direct and indirect benefits they might receive from the planted forests. The whole questionnaire started with asking for general information, followed by three components (Appendix 1). The first component had 19 questions with an objective to assess the trend of nature’s contribution to people in the past 15 years. The second component had four questions seeking to evaluate the impact of afforestation on water resources. The third component with 16 questions was trying to assess the trend of the various usage of natural resources (i.e., wood, branches/​stems, roots, barks, leaves, flowers, fruits, seeds, nectar, resin/​sap, companion plants, mammals, birds, insects, fungi/​mushroom, others) in the last 15 years. To validate the survey results, we also conducted a field survey on the vegetation structure and floristic composition of Eucalyptus paniculata, which is the most common tree species in the forest areas (Nyambane et al. 2016). A survey plot of 400m2 was used to record botanical and local names of all vascular plants and tree heights within that area.

Figure 11.2 Integrated approach for data collection.

188  Urban Water Ecosystems in Africa and Asia 11.3  Results and discussions First of all, results from component 1, which is nature’s contribution to the people, are summarized in Figure 11.3. Order of contribution is air quality improvement> Community bonding>Regulation of microclimate>Soil and sediment quality>Freshwater availability> Local availability for both food and fodder>Habitat improvement>Pollination and dispersion of seeds>Reduction in the frequency of extreme weather events. With afforestation, different provisioning and regulating services have improved significantly. This had direct and indirect impacts on social well-​being by creating different job opportunities and reducing occurrences of theft and other crimes. To further investigate its social contribution, we did a survey to get the perception of local people using different indicators, and the result is shown in Figure 11.4. It indicates that community-​based plantations brought different benefits like social relations or bonding by creating job and decision-​making opportunities for women and improving law and order, while it also helped to build self-​identity for these people, among other benefits. Next, looking into the nexus between water and human well-​being, we have analyzed how this afforestation has improved the water resources in the neighborhood. The result is shown in Figure 11.5, and it indicates that among all benefits, afforestation improved water quality by improving its odor, transparency, detergent friendly physical appearance. Moreover, with healthier water bodies, the aesthetic values are enhanced and it can be used for fishing/​swimming. Finally, the frequency or number of waterborne diseases has also reduced, and the water table has recovered well in the past few years. To further validate the impacts of community afforestation on water quality, we compared the water quality in terms of E. Coli. at the spatial scale and the result is shown in Figure 11.6. It is found that in the upstream region where in the absence

Figure 11.3 Summary of a questionnaire survey to assess nature’s contribution to the people.

Ecosystem benefits of community plantation in Kenya  189

Figure 11.4 Perception of local people about the benefits from this community-​led plantation.

Figure 11.5 Impact of afforestation on water resources.

of water management infrastructure, the concentration of E. Coli. in the river water is relatively high. However, when passing through the forest, natural purification is being done and the concentration is gradually reduced toward the downstream region. 11.4  Afforestation type and its long-​term effect During the afforestation campaign, Eucalyptus plants (E. paniculata) were selected as it is a fast-​growing species. Most of these plants in our surveyed 400 m2 plot reached more than 25 m in height and 50 cm in maximum diameter at breast height (DBH). Seven different species (Eucalyptus paniculata, Brachylaena huillensis (silver oak), Vepris nobilis, Markhamia lutea, Vitex

190  Urban Water Ecosystems in Africa and Asia

Figure 11.6 Relation between community plantation and water quality.

keniensis (Meru oak), Warburgia ugandensis, and Poaceae sp.) were observed in the study area. The major usage and the related forest components that the respondents felt ‘increased’ were fuel-​medicine-​food and wood-​branches/​stems-​ leaves, respectively (Figure 11.7). Then we have compared the use richness and diversity richness between native and exotic species. The number of data elements related to indigenous and exotic elements reached 65 and 60 respectively. Then, the number of types of forest resource utilization (i.e., use-​richness) among indigenous and exotic elements was 10 and 7, respectively (Figure 11.7). Furthermore, the application of Shannon’s diversity index (H’) to the analysis of the same data

Ecosystem benefits of community plantation in Kenya  191

Figure 11.7  Summary showing (a) contribution of the forest resources to people, (b) Diversity index for number of types of forest products usage for indigenous and exotic plant species.

sets enabled us to show the differences between the two elements. The H’ value of indigenous elements was approximately 2.6 while that of exotic elements was approximately 1.9. This implies that for long-​term sustainability, we must choose a diverse group of plants that can maintain biodiversity and its related ecosystem services. 11.5 Conclusion During the 1980s, due to the high demand for wood, indigenous forest plant species were replaced by exotic plant species, mainly Eucalyptus, because of their rapid growth rate. Community-​ led afforestation programs brought a lot of positive changes in society namely job opportunities, peace, law and order, social harmony, self-​identity, water quality improvement, water level increase, air quality improvement, and habitat quality improvement. For local people and rural communities dependent on this forest, both indigenous and exotic species are contributing to

192  Urban Water Ecosystems in Africa and Asia producing livelihood support elements viz food, fodder, fuel, medicine, etc., and keeping the forest usage abundant. Exotic elements, like Eucalyptus, introduced in the forest reserve provided the stakeholders with benefits owing to their rapid growth. It is still unclear whether the indigenous/​native trees adopted in the above-​ mentioned tree planting activities will bring the same benefits as, or more than, those of exotic In consideration of the fact that the prime objective of the reforestation activities is to make local people’s lives more prosperous, it is important to conduct an assessment for clarifying the situations of natural resources and the related local needs among the target communities. Then, it is required to properly maintain ecosystem services based on the appropriate local ecological knowledge and to promote well-​balanced vegetation management coexisting with indigenous and exotic elements. Therefore, there should be harmony between both indigenous and exotic plant species, which can support both local demands and ecological sustainability; however, exact quantification is a matter of future study. The findings of this study can help forest managers and users to promote a well-​balanced landscape management for all beneficiaries including poor and vulnerable residents living around the forest reserve. As the area is data scarce and to quantify ecosystem services, we need to generate a lot of primary data as well as collect secondary data from different organizations, which is also being taken care of while drafting the future research proposal. Acknowledgments We would like to express our very great appreciation to Prof. Dr. Nzioka J. Muthama, Dr. Thita Thenya, Ms. Chantal Mariotte, Ms. Cristina B. Croze, Mr. Harvey Croze, Ms. Marion Kamau, and Dr. Gacuuru Karenge for their valuable support and constructive advice during the planning and implementation of this research work. Our grateful thanks are also extended to the staff of the following organizations: the University of Nairobi, Wangari Maathai Institute for Peace & Environmental Studies, Kenya Forest Service, The Green Belt Movement, and The Friends of Karura Forest Community Forest Association. Finally, the assistance provided by Ms. Phyllis Wamaitha, Ms. Balla Pauline Achieng, and Mr. Duncan was greatly appreciated. References Baral, Himlal, Manuel R. Guariguata, and Rodney J. Keenan. 2016. “A Proposed Framework for Assessing Ecosystem Goods and Services from Planted Forests.” Ecosystem Services 22 (September): 260–​68. https://​doi.org/​10.1016/​j.eco​ser.2016.10.002. Bioneers. 2015. The Green Belt Movement of Kenya with Wanjira Matai. Video. Website www.yout​ube.com/​watch?v=​D-​dpdKMr​PpE Eigenbrod, F., V. A. Bell, H. N. Davies, A. Heinemeyer, P. R. Armsworth, and K. J. Gaston. 2011. “The Impact of Projected Increases in Urbanization on Ecosystem Services.” Proceedings of the Royal Society B: Biological Sciences 278 (1722): 3201–​8. https://​doi. org/​10.1098/​rspb.2010.2754.

Ecosystem benefits of community plantation in Kenya  193 Fedele, Giacomo, Bruno Locatelli, Houria Djoudi, and Matthew J. Colloff. 2018. “Reducing Risks by Transforming Landscapes: Cross-​ Scale Effects of Land-​ Use Changes on Ecosystem Services.” PLoS ONE 13 (4): 1–​ 21. https://​doi.org/​10.1371/​jour​nal. pone.0195​895. Ferreira, Lucianna Marques Rocha, Luciana S. Esteves, Enio Pereira de Souza, and Carlos Antonio Costa Dos Santos. 2018. “Impact of the Urbanisation Process in the Availability of Ecosystem Services in a Tropical Ecotone Area.” Ecosystems 22 (2): 1–​17. https://​doi. org/​10.1007/​s10​021-​018-​0270-​0. Green Belt Movement [GBM]. 2016. The Green Belt Movement: Annual Report 2016. 16 p . Graydon, Nicola. 2005. “From Tiny Seeds… .” Ecologist 35(2): 36–​9. Green Belt Movement. n.d. Visit GBM. Website www.greenb​eltm​ovem​ent.org/​get-​invol​ved/​ visit-​gbm Hayashi, H., S. Meguro, K. Fujiwara, S. G. Mathenge, T. Furukawa, and A. Miyawaki. 2006. “Primary Study of Dry Forest Vegetation Around Nairobi City, Kenya.” Eco-​Habitat 13 (1), 23–​32. Hunt, Kathleen P. 2014. “‘It’s More Than Planting Trees, It’s Planting Ideas’: Ecofeminist Praxis in the Green Belt Movement.” Southern Communication Journal 79 (3): 235–​49. https://​doi.org/​10.1080/​10417​94X.2014.890​245. [KFS & FKF] Kenya Forest Service & Friends of Karura Forest, a Community Forest Association. 2016. Karura Forest Strategic Management Plan. 93pp. Kigmo, B. N., P. S. Savill, and S. R. Woodell. 1990. “Forest Composition and Its Regeneration Dynamics; A Case Study of Semi-​Deciduous Tropical Forests in Kenya. Afrcian Journal of Ecology 28: 174–​88. Kumar, P. 2019. “Numerical Quantification of Current Status Quo and Future Prediction of Water Quality in Eight Asian Mega Cities: Challenges and Opportunities for Sustainable Water Management.” Environmental Monitoring and Assessment 191: 319. Leverkus, Alexandro B., and Jorge Castro. 2017. “An Ecosystem Services Approach to the Ecological Effects of Salvage Logging: Valuation of Seed Dispersal.” Ecological Applications 27 (4): 1057–​63. https://​doi.org/​10.1002/​eap.1539. Lind, E. M., and M. E. S. Morrison. 1974. East African Vegetation. 257pp. Longman, London. MacDonald, Mia. 2005. “The Green Belt Movement: The Story of Wangari Maathai.” Yes Magazine, Mar. 25. Website www.yesm​agaz​ine.org/​iss​ues/​media-​that-​set-​us-​free/​the-​ green-​belt-​movem​ent-​the-​story-​of-​wang​ari-​maat​hai Mariotte, C. 2018. The regeneration of Karura forest-​The transformation of a plantation of exotic trees into its original state. MITI Magazine. Maathai, W. 2006a. The Green Belt Movement: Sharing the Approach and the Experience, New Revised Edition. 138pp. Lantern Books, New York. Maathai, W. 2006b. Unbowed. 314pp. Arrow Books, London. Millennium Ecosystem Assessment [MEA]. 2005. Ecosystems and Human Well-​ Being: Synthesis. Island Press, Washington, DC, p. 155. Muller, Eva U., Andrey V. Kushlin, Thais. Linhares-​Juvenal, Douglas. Muchoney, Shelia. Wertz-​ Kanounnikoff, and David. Henderson-​ Howat. 2018. The State of the World’s Forests: Forest Pathways to Sustainable Development. Rome, Italy, p. 118. Njeru, J. 2010. “‘Defying’ Democratization and Environmental Protection in Kenya: The Case of Karura Forest Reserve in Nairobi. Political Geography 29: 333–​342. Nyambane, D. O., J. B. Njoroge, and A. O. Watako. 2016. “Assessment of Tree Species Distribution and Diversity in the Major Urban Green Spaces of Nairobi city, Kenya.” Journal of Horticulture and Forestry 8 (2): 12–​23.

194  Urban Water Ecosystems in Africa and Asia Republic of Kenya. 2005. Kenya Gazette Supplement No. 88 (Acts No. 7). Republic of Kenya, Nairobi. Sansevero, Jerônimo B. B., Renato Crouzeilles, Felipe S. M. Barros, Alvaro Iribarrem, Rafael Feltran-​Barbieri, Juliana Silveira dos Santos, Agnieszka E. Latawiec, Helena N. Alves-​Pinto, Daniel Silva, and Bernardo B. N. Strassburg. 2016. “The Role of Natural Regeneration to Ecosystem Services Provision and Habitat Availability: A Case Study in the Brazilian Atlantic Forest.” Biotropica 48 (6): 890–​99. https://​doi.org/​10.1111/​ btp.12393. Sunderlin, W. D., E.O. Sills, A.E. Duchelle, A.D. Ekaputri, D. Kweka, M.A. Toniolo, S. Ball, et al. 2016. “REDD+​at a Critical Juncture: Assessing the Limits of Polycentric Governance for Achieving Climate Change Mitigation.” International Forestry Review 17 (4): 400–​13. https://​doi.org/​10.1505/​146​5548​1581​7476​468. van Breugel, Paolo, R. Kindt, Jens Peter Barnekow Lillesø, M. Bingham, S. Demissew, C. Dudley, Ib Friis, et al. 2015. Potential Natural Vegetation Map of Eastern Africa (Burundi, Ethiopia, Kenya, Malawi, Rwanda, Tanzania, Uganda and Zambia). Version 2.0. Forest and Landscape (Denmark) and World Agroforestry Centre (ICRAF). www. veget​atio​nmap​4afr​ica.org (Accessed 2019 June 11). Verdcourt, B. 1962. The Vegetation of the Nairobi Royal National Park. In: Heriz-​Smith S. (ed.) The Wild Flowers of the Nairobi Royal National Park, pp.38–​49. D.A. Hawkins Ltd., Nairobi. Wang, Jiali, Weiqi Zhou, Steward T.A. Pickett, Wenjuan Yu, and Weifeng Li. 2019. “A Multiscale Analysis of Urbanization Effects on Ecosystem Services Supply in an Urban Megaregion.” Science of the Total Environment 662: 824–​33. https://​doi.org/​10.1016/​ j.scitot​env.2019.01.260. Wilson, Sarah Jane, John Schelhas, Ricardo Grau, A. Sofía Nanni, and Sean Sloan. 2017. “Forest Ecosystem-​ Service Transitions: The Ecological Dimensions of the Forest Transition.” Ecology and Society 22 (4). https://​doi.org/​10.5751/​ES-​09615-​220​438. Zhang, Yushuo, Lin Zhao, Jiyu Liu, Yuli Liu, and Cansong Li. 2015. “The Impact of Land Cover Change on Ecosystem Service Values in Urban Agglomerations along the Coast of the Bohai Rim, China.” Sustainability (Switzerland) 7 (8): 10365–​87. https://​doi.org/​ 10.3390/​su7​0810​365. Zhu, J. J., X. Zheng, G. G. Wang, B. F. Wu, S. R. Liu, C. Z. Yan, Y. Li, et al. 2017. “Assessment of the World Largest Afforestation Program: Success, Failure, and Future Directions.” BioRxiv, 105619. https://​doi.org/​10.1101/​105​619.

Appendix –​1 Full questionnaire General Information Name of the respondents

Age: years

Gender Male (1)/​Female (2)

Educational Qualification

Village Name

Monthly income

Occupation Agri/​ Forestry/​ Services/​Others

Approximate distance between your house to the planted forests?

kms

Ecosystem benefits of community plantation in Kenya  195 Questionnaire (Research component 1) 1. Please indicate (encircle) whether the following benefits (NCP: Nature contribution to people) increased or decreased since the last 15 years? Nature’s Contribution to People

1: Habitat Creation and Maintenance (e.g. some population of some beneficial species increased/​ deceased etc.)

1. Increased 2. Deceased 3. No change 4. I have no idea

2: Pollination and Dispersion of Seeds

1. Increased 2. Deceased 3. No change 4. I have no idea

3: Air Quality

1. Increased 2. Deceased 3. No change 4. I have no idea

4: Regulation of Micro-​climate (e.g. temperature, local rainfall etc.)

1. Increased 2. Deceased 3. No change 4. I have no idea

5: Availability of Fresh water (e.g. ponds, streams revived or lost)

1. Increased 2. Deceased 3. No change 4. I have no idea

6: Soil and sediment quality (fertility improved, soil erosion restricted)

1. Increased 2. Deceased 3. No change 4. I have no idea

7. Regulation of the impacts of hazards and extreme events

1. Increased 2. Deceased 3. No change 4. I have no idea

196  Urban Water Ecosystems in Africa and Asia Nature’s Contribution to People

8. Local availability of food and fodder

1. Increased 2. Deceased 3. No change 4. I have no idea

9. Community bonding, social life, peace and order

1. Increased 2. Deceased 3. No change 4. I have no idea

2. Please indicate whether you agree with the following statements. 1. The Green Belt Movement increased our financial income and reduced unemployment Strongly Disagree

Disagree

Neutral

Agree

Strongly agree

2. The Green Belt Movement changed our perception of viewing the environment differently. Strongly Disagree

Disagree

Neutral

Agree

Strongly agree

3. The Green Belt Movement has contributed enormously to build a self-​ identity for us. Strongly Disagree

Disagree

Neutral

Agree

Strongly agree

4. The Green Belt Movement has contributed enormously to improve law and order. Strongly Disagree

Disagree

Neutral

Agree

Strongly agree

5. The Green Belt Movement has contributed enormously to improve our social relations. Strongly Disagree

Disagree

Neutral

Agree

Strongly agree

Ecosystem benefits of community plantation in Kenya  197 6. The Green Belt Movement has contributed enormously to foster better relationship with the outer world. Strongly Disagree

Disagree

Neutral

Agree

Strongly agree

7. The Green Belt Movement has contributed to an interest for studying nature closely. Strongly Disagree

Disagree

Neutral

Agree

Strongly agree

8. The Green Belt Movement has contributed to self-​dependence and realization of our own potentials Strongly Disagree

Disagree

Neutral

Agree

Strongly agree

9. The Green Belt Movement has contributed to the participation of women in crucial decision-​making Strongly Disagree

Disagree

Neutral

Agree

Strongly agree

10. The Green Belt Movement has contributed to the development of environmentally sustainable attitudes such as water conservation, biodiversity protection etc. Strongly Disagree

Disagree

Neutral

Agree

Strongly agree

Questionnaire (Research component 2) 1. What is the trend of groundwater table in your locality within last 20 years and their relation to planted forests by the Green Belt Movement (GBM)? a. The water table is increasing /​decreasing because of forest plantation b. No obvious change because of forest plantation c. Water table is decreasing but because of other factors (population growth, urbanization, climate change) d. Can’t say anything

198  Urban Water Ecosystems in Africa and Asia 2. What are the issues with surface water resources in your neighborhood and their recent trend? a. Physical appearance is getting worse /​better b. Aesthetic value is getting worse /​better c. Fishing /​swimming /​tourism activities getting worse /​better 3. Do you have any issues regarding water quality in your neighborhood and their recent trend? a. Bad odor (due to high nitrate/​ammonia and eutrophication) and it is increasing b. Less foam formation with detergent (High hardness because of increase in sediment load due to forest plantation) and it is deteriorating c. Not colorless /​Less transparent /​Hazy and it is deteriorating d. Other issues (please mention in detail) e. No issues 4. Do you have any health issues related to water/​forest in recent past? a. Gastroenteritis (high Ecoli /​High pathogen contents because of untreated sludge infiltration) b. Cholera c. Typhoid d. Malaria or any mosquito borne diseases because of planted forest Questionnaire (Research component 3) What benefits could you receive from the planted forests by the Green Belt Movement (GBM)? *1: Please put check-​marks at the natural resources you use in daily life. *2: Please describe the details of the resources (usage or purpose) and species information using biological or vernacular names. *3: Please circle the appropriate arrows showing tendency to increase (↗) /​decrease (↘) /​ no-​changes (→) in the resource quantity estimated based on your experience since the GBM’s reforestation started.

☑*1

Natural resources Usage/​Purpose*2

□

Wood

↗

↘

→

□

Branches/​Stems

↗

↘

→

□

Roots

↗

↘

→

Species name*2

Tendency*3

Ecosystem benefits of community plantation in Kenya  199 ☑*1

Natural resources Usage/​Purpose*2

□

Barks

↗

↘

→

□

Leaves

↗

↘

→

□

Flowers

↗

↘

→

□

Fruits

↗

↘

→

□

Seeds

↗

↘

→

□

Nectar

↗

↘

→

□

Resin

↗

↘

→

□

Companion plants

↗

↘

→

□

Mammals

↗

↘

→

□

Birds

↗

↘

→

□

Insects

↗

↘

→

□

Fungi/​Mushroom

↗

↘

→

□

Others

↗

↘

→

Object forest to be targeted in your answers Location:   Trees age /​ Planting year:

Species name*2

Tendency*3

12 The production of hydrosocial space in contemporary China Gianni Talamini and Di Shao

12.1 Introduction Hydromorphological transformations often occur parallel to socioeconomic development and associated changes in hegemonic values (Winiwarter et al., 2016). Meanwhile, modernity translated into an engineering control of natural resources, perceived as inexhaustible. The initial phase of industrialization radically transformed watercourses regarding fluvial geomorphology, pollution levels, and the employment of rivers as waterways. Through industrialization, urban watercourses changed to flood control channels and repositories for sewage effluents, while the modal shift to road haulage followed the abandonment of many small and medium waterways (Wolf et al., 2021). Degraded landscapes crossed by open-​air concrete sewers ultimately became a stigma for many developing cities. Growing awareness of how industrialization impacts ecosystems then began to spread following the harmful effects of synthetic substances on human and ecological communities (Carson, 1962). Pollution of rivers has become a global concern as well, following the evidence-​based, causal relationship between pollutants and human diseases (Lin et al., 2022). Water systems reflected the fragility of ecosystems, calling for a holistic approach to remediation. Contextually, policymaking crystallized this new ecological imperative into legislation. Urban rivers subsequently became the object of public investment of massive resources (Everard & Moggridge, 2011; Shannon & Chen, 2014). Against the background of a dynamic evolution of water and society, the concept of ‘hydrosocial space’ emerged to express the social and spatial forms of such a symbiotic relationship (Linton & Budds, 2014; Swyngedouw, 2009). Hydrosocial research critiques the traditional hydrological approach that treats water as a mere resource to situate water in its social context. By employing a relational-​dialectical approach, socio-​hydrology demonstrates the dynamic coevolution process to ‘conceptualize the hydrosocial cycle as a socio-​natural process by which water and society make and remake each other over space and time’ (Linton & Budds, 2014, p.170). This perspective suggests a relationship exists between the transformation of the urban hydrological environment and the social, political, economic, and cultural structures of power (Swyngedouw, 2004; Ross & Chang, 2020). Using that theoretical prism, this chapter attempts to investigate the association DOI: 10.4324/9781003437833-12

The production of hydrosocial space in contemporary China  201 between policymaking, societal values, and hydromorphological transformations by focusing on one of the fast-​developing regions globally, the Guangdong–​Hong Kong–​Macao Greater Bay Area (GBA). Driving questions within this investigation focus on both the relationship between these three domains (Are policies and societal values reflecting each other, and how are they shaping the production of river space?) and the lessons to be learned from such an evolution (Should other developing regions follow the same paths, or can some issues be better addressed at an earlier stage?). The remainder of this chapter is structured in three main parts. First, the policies of water management in the GBA are reviewed to illuminate not only the understanding of water in policy formulation but also the evolving objectives and strategies of water management in the context of rapid urbanization. Second, content analysis is employed for policies and newspaper articles to further investigate the shift in the hegemonic societal values of water management. Finally, one case of river regeneration practices in Shenzhen is dissected to demonstrate how changes in policies and hegemonic values affect hydromorphological transformations. 12.2  A water-​rich region: the GBA The GBA, also referred to as the Pearl River Delta (PRD) Metropolitan Region, is a megalopolis in Guangdong Province, comprising nine cities (Guangzhou, Shenzhen, Zhuhai, Foshan, Dongguan, Zhongshan, Jiangmen, Huizhou, and Zhaoqing) and two special administrative regions (Hong Kong and Macao; Figure 12.1). As one of the most economically developed parts of China, the GBA’s combined regional Gross Domestic Product (GDP) was estimated at approximately US$2 trillion in 2022, equivalent to 11% of China’s GDP. The GBA historically developed symbiotically with an extensive hydrological infrastructure: that of the Pearl River (Zhujiang) estuary, one of China’s highest river network densities (1.03 km/​km2). The tight relationship between human settlements and China’s second-​largest river by volume produced peculiar waterscapes and water-​associated cultural attributes (Lu & Talamini, 2024). Some examples are the pearls that gave the name to the Zhujiang River and were central to the local jewelry industry for centuries, and the Tankas, an ethnic group who traditionally lived on junks and formed stilt house settlements (e.g., Tai O). Nevertheless, over the last four decades, the hydrological infrastructure of the PRD –​which entails a diverse range of ecosystems that includes wetlands, mangroves, and coastal habitats –​has been severely stressed by unbridled urbanization patterns, possibly resulting from prioritizing economic development over ecological and social sustainability. Balancing economic development with ecosystem conservation and societal needs is a significant challenge in the GBA, just as in other fast-​developing regions. 12.3  GBA urbanization and its effects on rivers The GBA has been undergoing rapid urbanization since 1978, thanks to the Chinese economic reform, resulting in the GBA population growing from approximately

newgenrtpdf

202  Urban Water Ecosystems in Africa and Asia

Figure 12.1 GBA urbanization (left top: proportion of urban population; left bottom: built-​up areas development) and GBA river network (right). Sources: Guangdong Statistical Yearbook 2022 (Urban Population); Xu et al., 2018 (Built-up areas); OpenStreetMap.org (Rivers).

The production of hydrosocial space in contemporary China  203 17 million in 1978 to 86 million people in 2022. The fast urban development significantly impacted the centennial hydrological infrastructure and severely worsened river water quality (Ouyang et al., 2006). According to the Chinese environment quality standard for surface water (GB3838-2002), less than 40% of the river water is above Class III within the urban zones and remains safe for drinking in 2000 (Ouyang et al., 2006). A revelatory case is Shenzhen, a city founded following the Open Door Policy of 1978. Over the last four decades, the city’s industrial and tertiary sectors developed at an unprecedented rate. Concurrently, urban municipal waste discharge increased, and land use and land cover abruptly changed, severely polluting water resources and reducing the urban river network. As a result of this rapid development, Shenzhen’s river water was classified as seriously polluted, and Shenzhen’s urban river network was dramatically reduced. By 2002, all the river water in Shenzhen was worse than Class V of the Chinese environment quality standard for surface water (GB3838-​2002), with a value of COD more than 40 mg/​L and a value of BOD5 more than 10 mg/​L (Ouyang et al., 2006; Chen et al., 2011; SEPA, 2002). Additionally, in only three decades, the total length of Shenzhen’s river network decreased by 355.4 km (equal to 17% of the total length in 1980), the total number of streams decreased by 378, and the density of the river network decreased from 0.84 km/​km2 to 0.65 km/​km2 (Zhou et al., 2008). To limit the effects of such unsustainable development, administrators and policymakers put forward a series of measures with objectives that have changed over time, possibly reflecting the mutation of hegemonic societal values. 12.4  Pearl River Delta water management history and core policies Rapid urbanization ultimately led to the severe pollution of GBA rivers, and since the late 1990s, pollution control has become the most crucial objective of regional water management. In 1997, Guangdong Province launched the Clean Water Project Programme, formally establishing a regional water management framework. The program aimed to effectively protect water sources, prevent water pollution, improve the quality of water bodies, rationalize the use of water resources, and synchronize the development of economic construction with the protection of the water environment and water resources. Specific measures included completing inland water bodies improvement projects, accelerating the construction of domestic sewage treatment plants, identifying and controlling sources of industrial pollution, increasing the treatment and compliance rate of industrial wastewater, completing water resource protection planning, and strengthening scientific research on water environmental protection (GOPGGP, 1996). Eventually, by 2000, more than 20 billion RMB was invested in implementing six capstone projects and 115 sub-​projects to protect the PRD water quality (Wei, 2021). After the year 2000, a fundamental shift occurred in China’s approach to environmental protection: a shift from pollution control to pollution management. The change represents a shift from a passive approach to curbing the trend of increasing environmental pollution to a proactive approach to environmental management and the realization of improved environmental quality. In 2002, Guangdong Province

204  Urban Water Ecosystems in Africa and Asia issued the Decision on Strengthening the Integrated Remediation of the Pearl River and launched the Pearl River Remediation Project, which formally opened the prelude to transforming Guangdong’s water environment protection from pollution prevention and control to river basin remediation. The policy aimed ‘within one year to show initial results, within three years to eliminate black and odorous water bodies, [and] within eight years the river water becomes clear’ (GMPG, 2003). According to the Briefing on the Pearl River Integrated Remediation Programme, by the end of 2010, a series of remediation activities resulted in the water quality of the major rivers within the Pearl River Basin being maintained at a good level and the safety of drinking water sources being safeguarded; the water quality of the water bodies in the cities through which the water flowed being markedly improved; the level of industrial pollution prevention and control being markedly upgraded; and breakthroughs being made in the construction of urban domestic sewage treatment facilities (PRCRO, 2011). To consolidate the achievements of the comprehensive improvement of the Pearl River and further enhance the quality of the water environment, Guangdong Province proposed the Action Plan for Cleaner Water in Southern Guangdong (2013–​2020) in 2013. The plan laid out how to actively explore new water management ideas, customize the approach to Guangdong characteristics, reform the traditional passive-​response water management, and emphasize economic and social development in the background of water environmental protection and water environment carrying capacity. Then, in 2017, the General Office of the State Council of the Central Committee of the Communist Party of China issued the Opinions on Comprehensively Implementing the System of River Chiefs to create a mechanism for managing and protecting rivers and lakes. Subsequently, in 2018, Guangdong Province carried out the Five Clear-​Up Special Action, focusing on inland bodies of water (rivers, lakes, and reservoirs) to comprehensively tackle illegal sewage outfalls, remove floating debris, clean sediment pollutants, eliminate physical obstacles to the water flow, and eradicate illegal and unauthorized structures. Meanwhile, Guangdong Province implemented the Make Guangdong Rivers More Beautiful Action. The policies targeted 2020 as a deadline for the province’s rivers and lakes to become safe water supply channels and healthy ecological corridors, with banks rehabilitated into recreational greenways to provide users with an enhanced physical environment. By the 2020s, Guangdong Province’s water management had moved from control to culture and economy, as reflected by the 10,000 kilometers of eco-​belts construction in Guangdong Province (Guangdong eco-​belts) proposed in 2020. The Guangdong eco-​belts are a network of inland water bodies integrating ecological, safety, cultural, landscape, and recreational functions, such as serving as ecological corridors, cultural and recreational greenways, and waterfront economic zones. The plan thoroughly explores the ecological potentials of restored river systems to provide the public with high-​quality ecological areas and guide people closer to nature for a green and healthy lifestyle. The plan is the first in Guangdong Province to focus on constructing waterfront spaces. Specifically, the plan aims to integrate

The production of hydrosocial space in contemporary China  205 the spatial pattern of ecology, human life, and production activities in the urban environment from the perspective of users’ needs. 12.5  Innovative policy and practice: Shenzhen water strategy Shenzhen’s advanced economy and international importance mean the city plays a unique role in China and the Guangdong province in testing new policies and water management strategies. In 2019, the Shenzhen Municipality released the Shenzhen Water Strategy 2035, which aims to establish a water-​related sustainable development model for the city’s economy, society, and environment and to build a ‘water-​ friendly and resilient city’ (WASM, 2019). The strategy covers six water-​related areas (i.e., resources, environment, ecology, safety, economy, and culture) and ten significant actions (see Table 12.1). Notably, the strategy has been under study since 2003, with the first report completed in 2006. The strategy is China’s first systematic and comprehensive approach to solving water problems. 12.6  A shift in hegemonic values: evidence from policy and gray literature The synopsis of the water-​related policy development presented above highlights a transformation in the objectives of water management from a narrow focus on urgent sanitation issues to general improvements of the environment to enhance inhabitants’ quality of life. To further investigate the shift in hegemonic values, content analysis was employed in this study to examine policies and newspaper articles; the corpus-​assisted discourse analysis was used to examine the corpora of Newspapers and Policies related to the theme of Rivers in the GBA. The analysis applied a corpus linguistic methodology to explore the relationship between discourse and society. Applying that methodology allowed the researcher to systematically investigate large sampled texts through quantitative and qualitative lenses (Gillings et al., 2023). The first step was corpus building; relevant policies were retrieved from the governmental websites of departments responsible for water management, urban planning, and environmental protection. The collection included municipal documents directly or indirectly related to water management and provincial or national documents that have significantly impacted water management in the GBA. Four types of documents were collected: laws, strategies, opinions, and overall plans. For this research, a total of 135 policies: 16 national policies, 24 provincial policies, and 95 municipal policies, met the criteria and were subsequently analyzed. For the newspapers corpus, data were retrieved from the Wiser Information Portal database. In the Wiser Information Portal, one core daily newspaper for each city in the GBA was chosen based on the local relevance of the newspapers (typically, the first choice was the Daily News of each city). Newspaper data were unavailable for two (of nine total) GBA cities: Zhuhai and Zhaoqing. Therefore, seven newspapers were selected. The term river in Mandarin (河) was used as the query term for searching articles in headlines and content. The publication period depended on the database availability, the most prolonged period

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No. Policy Title

Years

C1a Clean Water Project 1997 Programme to 2000

Core Contents • • • •

Improve the water environment of rivers, lakes, and reservoirs with serious water pollution; Construct domestic sewage treatment plants in urban areas; Treat industrial pollution sources and improve the industrial wastewater treatment rate and compliance rate; Conduct water resources protection planning, completing the division of the province’s water environment functional zones and strengthening the regulations; • Enhance scientific research on water environment protection, relying on scientific and technological progress and utilizing new technologies and new means to effectively control water pollution. C2 Decision on 2002 • Implement integrated remediation programs, including control of the total amount of major pollutants via Strengthening to industrial pollution control, domestic sewage treatment, livestock farming pollution control, surface water the Integrated 2010 pollution control, and integrated management of river channels; Remediation of • Accelerate the construction of sewage treatment facilities; the Pearl River • Strengthen the ecological protection of the watersheds; • Ensure remediation capital investment; • Strengthen the leadership and supervision of remediation work. C3 Action Plan for 2013 • Implement zoning controls, including establishing ecological red lines, optimizing water supply and drainage Cleaner Water to channels, strengthening the construction of ecological public welfare forests and wetland protection, and in Southern 2020 optimizing the industrial layout; Guangdong • Implement a strict environmental impact assessment system and sewage discharge standards, as well as a (2013–​2020) mechanism for eliminating backward production capacity to promote industrial transformation and upgrading; • Strengthen the protection of drinking water sources and ensure the safety of drinking water; • Promote integrated environmental remediation and continuously improve the quality of the water environment; • Strengthen environmental supervision and raise the level of water pollution prevention and control; • Strengthen monitoring and early warning capacity building and enhance scientific decision-​making; • Innovate mechanisms and institutions to strengthen water environment management. C4 Opinions on 2017 Establish a four-​tier system of river chiefs at the provincial, municipal, country and township levels. Party Comprehensively to and government leaders serve as river chiefs to implement the main responsibilities of local authorities. Implementing the present River chiefs should coordinate and integrate the efforts of all parties to vigorously promote the protection of System of River water resources, the management of waterside shorelines, the prevention and control of water pollution, the Chiefs treatment of water environments, and the restoration of water ecosystems.

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Table 12.1 Core policies of Pearl River Delta water management

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2020 to 2035

I1b Shenzhen Water Strategy 2035

2019 to 2035

a. C: Core policy. b. I: Innovative policy.

• Guarantee water resources, promote the connectivity of river and lake water systems, and realize the uninterrupted flow of rivers; • Improve water safety, perfect the flood prevention and mitigation system, guarantee the safety of river flooding, and alleviate the pressure of flooding in cities; • Improve the water environment, promote river outfall remediation, control surface pollution, strengthen river garbage remediation, and realize clear water in rivers and lakes; • Protect and restore water ecology, strengthen preservation of water conservation areas, protect aquatic habitats, and construct river ecological corridors; • Build landscape and recreational systems and construct recreational waterfront greenway; emphasize the protection and display of water culture and highlight regional cultural characteristics; • Jointly build ecologically vibrant waterfront economic zones and promote industrial upgrading and high-​ quality development. Toward a ‘water’-​led model of economically, socially, and environmentally sustainable urban development through ten key actions: • Pollution control: source reduction, wastewater collection, expanded treatment capacity, river restoration with dredging and recharge; • Water supply: water conservation, wastewater reuse, water supply network improvement, non-​conventional water, and direct drinking water supply; • Water purification: initial stormwater runoff pollution control, maximum pollution emission control, water purification plant construction; • Living water: wetland construction, ecological corridor construction, ecological restoration, river rehabilitation; • Soft water: stormwater pipe network and river flood discharge capacity enhancement, sponge-​city facilities construction, stormwater storage; • Blue water: eco-​belts construction, ecological corridor construction, waterfront economic complex construction; • Intelligent water: smart water platform for water environmental monitoring and risk prevention, water science and technology industries development; • Water rich: marine economy, coastal eco-​tourism, new model of water investment and financing, water market system improvement; • Water revitalization: water culture system and water culture carriers construction, water forum +​water museum +​water expo; • Water research: promoting basic scientific research and improving the regulatory system of water management.

The production of hydrosocial space in contemporary China  207

C5 10,000 Kilometers of Eco-​Belts Construction in Guangdong Province

208  Urban Water Ecosystems in Africa and Asia being the one of the Shenzhen Special Zone Daily with available data from 2000–​ 2023, excluding 2002. Next, the articles were filtered based on the headlines in the search results. The relevant items, those focusing on water governance, were then downloaded to form the dataset. Following that step, a quick full-​text browse was performed to remove items unrelated to the research topic. Eventually, 13,482 articles from 2000 to 2023 were included in the dataset for this research. In the subsequent step, a longitudinal study of the quantitative changes in keywords in Policies and Newspapers was performed to compare the changes over time. Frequency information was then used to identify the most prominent discourses within the corpus and compare the individual linguistic units in different years’ corpora. With such a purpose, the documents were organized according to the year of release. Then, all the documents were imported into NVivo 14 for word frequency analysis by year using the Word Frequency Query. A wordlist ordered by linguistic unit frequency could then be produced. Selected keywords related to the research topic from the wordlists were compared in their relative frequency by years. Further, the weighted percentage was calculated automatically in NVivo and thus employed to show the relative frequency of each keyword. On the one hand, the frequency count is relatively higher for Policies, possibly reflecting the prioritarian importance of the selected keywords for the governmental bodies (Figure 12.2). On the other hand, the smoother trend in newspapers may not reflect a comparative variance and could be interpreted as an analytical limitation due to the different sample sizes. Nevertheless, the results clearly illustrate changing priorities for both Policies and Newspapers: pollution, pollution control, and water quality have gained less attention since the late 2010s in favor of notions such as ecology. This development may demonstrate the effectiveness of water improvement strategies put forward since the late 1990s. Concurrently, the comparative inquiry of keywords such as Culture, Economy, and People highlights different trends in the two datasets. While the frequency of these keywords in Policies has been constantly shrinking –​especially in the case of the Economy –​the presence of the keywords in newspapers has steadily risen. Despite both the policymaking process and news publication being under the strict control of the central government, the different trends may demonstrate how policy priorities may be more affected by vertically imposed directions. Moreover, the positive trends show a growing river-​related general interest in cultural and socioeconomic progress. Eventually, responsive policymaking may be seen as a way to promptly address growing societal concerns for cultural development, economic advancement, and people’s prosperity while envisioning new integrated approaches in river management. 12.7  Case study: the Dasha River Within Shenzhen, changes in policies and hegemonic values affected several water bodies. One particular case, that of the Dasha River, especially reveals such a transformation process and can provide crucial insights. The Dasha originates from the Yangtai Mountain in Shenzhen’s Nanshan District (Nanshan). The river sprouts from the Chang Lingpi reservoir, crossing the whole district and flowing

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The production of hydrosocial space in contemporary China  209

Figure 12.2 Word frequency count for Policies and Newspapers.

210  Urban Water Ecosystems in Africa and Asia into Shenzhen Bay, with a total length of 13.7 km and an estimated watershed of 92.63 km2, accounting for 49% of the area of Nanshan. The Dasha is the only river in Nanshan with a watershed area greater than 50 km2. In addition, the Dasha is the mother river of Nanshan, an area of Shenzhen crucial for the high-​tech industry, higher education, tourism, and logistics; in 2022, the GDP of Nanshan reached 803.6 billion RMB, ranking first in Guangdong Province and third in China (Talamini et al., 2022). According to the district government (Shenzhen Special Zone Daily, 2009), the Dasha provides favorable natural conditions for developing high-​tech and innovation in Nanshan. Geographically, the Dasha runs through two major high-​tech parks in Nanshan, Shenzhen University and University Town (a hub comprising six Chinese higher education institutions). Moreover, the areas along the river are the most active zones of science and technology innovation. Therefore, the Dasha serves as not only a crucial ecological corridor linking Yantai Mountain and Shenzhen Bay but also an innovation corridor for Shenzhen. The Dasha got its name (Da Sha, literally meaning ‘big sand’) for traditionally being a local source of sand. In the 1980s, rivers in Shenzhen appeared clean with good water quality. However, the high amounts of urbanization and industrialization have seriously polluted the rivers. By 1995, the riverbed of the Dasha was seriously silted up, the water was black and smelly, and fish were extinct. The river’s flooding capacity was also extremely poor, and every heavy rainfall brought severe flooding (Yang, 2010). During the torrential rains of 1992, 1993, and 1994, for example, both banks of the Dasha were inundated with floodwaters, causing economic losses of more than 200 million RMB (Zhang & Yue, 1999). Therefore, in the mid-​1990s, Shenzhen initiated a river rehabilitation process (Figure 12.3). 12.8  The Dasha rehabilitation process The rehabilitation of the Dasha included three distinct phases. The first phase, which began in 1996 and ended in 2003, focused on flood safety. For the second phase, which began in 2009 and ended in 2016, the aim was mostly to address the issue of water pollution. The third phase, from 2017 to 2019, primarily enhanced the river landscape to shape Shenzhen’s ‘Seine River’ (Li, 2019). 12.8.1  Phase I. Flood safety (1996–​2003)

Prior to 1996, the Dasha was a meandering natural river without systematic and comprehensive engineering management. The original embankment standard was equivalent to the one-​in-​five-​year design flood standard. The upper course had a riverbed width of 10–​20 m, allowing a maximum water flow of 60–​80 m3/​s; in heavy rainfall, the width of the flooded areas reached 50–​100 m. After merging with the spillway of Xili reservoir, the Dasha turns to run from north to south. In that section, comprising the middle and lower courses, the flooded area reached up to 160 m in width. Some narrow sections of about 30 m had water flow limited to 200 m/​s (Liu et al., 1999). Due to the low standard of the original embankment of the Dasha, as well as the meandering of the river channel and the siltation of the

The production of hydrosocial space in contemporary China  211

Figure 12.3 Comparison of the Dasha before and after rehabilitation (top left: 1977; top right: 2022; bottom left: 1987; bottom right: 2022). Source of bird photographs: Chen Zonghao; source of historic satellite imagery: United States Geological Survey.

riverbed, flood disasters occurred frequently. Governmental records showed that, from 1989 to 1993, six flood disasters occurred in the Dasha River basin, resulting in three deaths and a direct economic loss of 29.5 million RMB. Rapid urbanization and economic development resulted in higher demands on urban rivers. In 1994, the Shenzhen Master Plan (Revised) Outline set the ambitious target of developing the city into a multi-​functional international hub with sufficient space for leisure activities and a lush landscape (Chen, 2022). Subsequently, in September 1995, the Shenzhen Mayor’s Conference passed a resolution to manage

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212  Urban Water Ecosystems in Africa and Asia Figure 12.4 Top: Combined sewer overflow section in Dasha in Phase II (above) and Phase III (below). Bottom: Combined sewer overflow in Phase II (left) and Phase III (right). Source: Authors.

The production of hydrosocial space in contemporary China  213 the Dasha per the flood prevention standard of one in 200 years to transform the Dasha into a model river with practical and ornamental value. Hydromorphological transformations followed; the transformations included the rectification of the river to allow space for new traffic arteries, residential areas, and golf courses. In addition, seven rubber dams 2–​3 m high were installed. During the flood season, the dams were deflated to allow water to flow; in the dry season, the dams were filled with water to hold the incoming flow, forming a 500–​2000 m long water body for recreational activities. The river cross-​section was also designed as a compound channel geometry composed of two trapezoids, with the lower part comprising a small channel holding a permanent flow (Figure 12.4). In the upper course of the Dasha, the small channel had a concrete surface, while the rest of the river embankment was coated with turf to maintain a more natural landscape. In the middle and lower reaches of the river, the width of the river was constrained by the construction plan on both sides. Thus, to reach the flood control standard of once per 200 years, all the slopes of the compound trapezoidal section were protected by concrete, with grass on the riverbed and trees on the top of the embankments. The Dasha improvement project also needed to address the issue of stormwater drainage in the watershed. Originally, more than ten tributaries to the river were present; however, due to urbanization, stormwater was collected into municipal sewers, which flow to 60 culvert outlets on both riverbanks and discharged the stormwater runoff (Liu et al., 1999). 12.8.2  Phase II. Water pollution management (2008–​2016)

After the first stage of flood control and management, two critical issues still had to be addressed: 1) soil erosion leading to severe siltation and 2) serious water pollution. In 1999, nearly 600 quarry sites of different scales, with a total area of 2.499 km2, were active in the Dasha basin, causing a yearly sediment deposit of 8.105 million m3 (Zhang & Yue, 1999). Concurrently, the inadequate municipal sewage system was responsible for the severe pollution of the Dasha; some old villages were not connected to the municipal sewage network in the upper course. Additionally, many illegal farms, processing factories, and illegal dumps were present around the upper reaches, leading to domestic sewage and industrial wastewater being discharged into the Dasha without treatment. Water pollution control thus became a critical task in the second phase, and the following quality improvement actions were taken: 1) Establish an interception system to prevent untreated sewage and stormwater runoff from being directly discharged into the river (Talamini et al., 2017): the system consists of interception pipes and box culverts running under the embankments. The intercepted effluent was to be led into the municipal sewage system and treated in the wastewater treatment plants. 2) Build sluice gates, sewage treatment plants, sewage lifting pumping stations, and other support facilities, and install water recharge and quality improvement facilities. Accordingly, the Xili water reclamation plant became Shenzhen’s first

214  Urban Water Ecosystems in Africa and Asia sewage reclamation and reuse plant; the reclaimed water was discharged into the Dasha for landscape purposes, allowing a relatively large permanent flow even in the dry season (Liu et al., 2008). Additionally, a sluice gate was installed at the estuary of the Dasha to hold back the tidal flow from Shenzhen Bay and store water, forming a permanent water body with a surface of about 2 km in length and 95 m in width and enhancing the water exchange capacity of the river (Cai, 2020). 3) Improve the urban sewerage system and resolve the problems of pipe network disconnection and misconnection. The second phase of river management optimized the river cross-​section to achieve enhanced ecological function. Specific approaches included ecological mitigation measures, such as installing gabions below the normal water level and greening the upper parts of the embarkments. Concrete embarkments built in the first phase were also demolished –​to build underground culverts –​and replaced by vegetated surfaces; the concrete riverbed was retained. 12.8.3  Phase III. Ecological Corridor construction (2017–​2019)

The third stage in the river management consisted of constructing the Dasha River Ecological Corridor focused on river ecological restoration and riverside landscape enhancement. During this phase, an ecological landscape project was implemented without destroying the previous water safety measures. A renowned American multinational infrastructure consulting firm drafted the landscape enhancement project with the aim of improving the quality of the riverine green environment, walkways, bicycle paths, and user safety. This project was committed to creating a natural, ecological, comfortable, and pleasant riverside space in Shenzhen (Shenzhen Nanshan District People’s Government, 2019). In October 2019, the entire section of the Dasha River Ecological Corridor officially opened, becoming the most extensive riverfront slow-​waking system in Shenzhen. About 24,000 people visit the area daily (Shenzhen Special Zone Daily, 2021). Eventually, the construction of the ecological corridor radically transformed Nanshan, providing Shenzhen with an extraordinary lush landscape of great social and economic value. Despite evident limitations, the Dasha can arguably be considered a successful river rehabilitation case in contemporary China and offers an exemplary model for similar cases in and beyond China. Yet the significant investment of resources needed for such an extensive hydromorphological transformation may not be available to other municipalities. Further, given the current knowledge, the reduction of the river space for mobility infrastructure, residential purposes, and golf facilities arguably could have been avoided. The combined sewer system also poses insurmountable problems (e.g., untreated discharges into the river) difficult to address a posteriori. Such invaluable lessons are crucial for developing urban areas that can still conceivably construct sanitary sewers and allow enough space along the river course for constructed wetlands to treat urban runoff. In climate areas prone to

The production of hydrosocial space in contemporary China  215 heavy rain, this type of integrated approach is crucial since rain in such areas typically leads to overflow events in combined sewers (Talamini et al., 2017). 12.9 Discussion 12.9.1  The coevolution of society and water

The theoretical perspective of hydrosociology provides a ‘relational-​dialectical’ approach (Linton & Budds, 2014) to explore the coevolution process of a socio-​ nature system in which society and water make and remake each other spatially and temporally. The rapid urbanization and industrialization of the Pearl River Delta society are reflected in the transformation process of the hydrological environment. The hydromorphological transformations of the Dasha River have also been infused with Shenzhen’s political and social practices, cultural connotations, and engineering technologies. Before 1978, Shenzhen was a village with a total population of 300,000, who mainly made a living from farming and fishing (Shenzhen Statistical Yearbook, 2021). The Dasha River was a natural river flowing through a rural area and collected water for the irrigation of agricultural lands (see Figure 12.3, Dasha River image in 1977). Thanks to the reformation and opening policy of Deng Xiaoping and the establishment of the Special Economic Zone, Shenzhen experienced rapid urbanization and industrialization between 1978 and 2000 and transformed into a ‘World’s Factory’ characterized by labor-​intensive manufacturing and an export-​ oriented economy. At that time, the pursuit of development efficiency and benefits outweighed environmental concerns. Along with urbanization, impervious surfaces in the city were increasing significantly as well, and then water was becoming a problem in terms of flooding and pollution (Liu & Yang, 2018). Meanwhile, with the evolution of technological development, engineering-​oriented thinking dominated social development and influenced hydrological transformation. Buildings and factories replaced large tracts of agricultural lands in river basins, and rivers were channelized as sewage drains and floodways. During this period, rivers were considered ugly, smelly, and dangerous, losing any connection with people’s daily lives. Meanwhile, the recreational and cultural values of the rivers were not the priority for the workers who migrated from the rural to the urban areas in the hope of escaping poverty. As the Chinese government recognized the significance of the high-​tech industries, new policies were announced in 1992 to support the industry transformation (Yip & Lim, 2022), and after 2000, Shenzhen became a technological hub known as a source of cheap copycat products. In the last two decades, Shenzhen has progressively become recognized as the Chinese Silicon Valley due to the clustering of famous high-​tech companies, such as Hua Wei, Tencent, and DJI. Subsequently, the water environment in Shenzhen has been seen as an opportunity to enhance the urban built environment. This changing role of the urban hydrological environment is reflected in its coevolution with society. According to the latest Pilot Reform Plan for 2020–​2025, Shenzhen will be built as a world-​class, innovative city by 2025 (The Communist Party of China

216  Urban Water Ecosystems in Africa and Asia Central Committee, 2019). Such a planning vision widely recognizes that high-​ quality natural and green environments are critical factors in attracting capital, talent, and tourists to cities in the era of creative industries (Guo & Talamini, 2017). Therefore, urban rivers, as the natural backbone intertwined with the high-​density built-​up areas of the city, become essential for cities in providing green spaces for citizens, especially for the middle classes who work in high-​tech companies along the water streams. Following such a trajectory, a growing ecological awareness and demand for healthy lifestyles may be reflected in the future reintegration of agriculture as urban farming along rivers (Talamini et al., 2022). 12.9.2  Changing hegemonic societal values in water management and landscape

The water management and water policies in the GBA demonstrate how rivers were conceived as water resources and constraints to urban development in the context of rapid urbanization. The main policies for water management emerged in the late 1990s, with pollution prevention and control as the primary objective. Before that period, water management was an aspect neglected by urbanization priorities. The water environment was first polluted, then treated, and eventually became an engine of economic development, in which the ‘value’ of water was defined by the needs of society and served a specific stage of socioeconomic development. Today’s urban rivers, which have undergone many artificial modifications, are used as representatives of a city image that conforms to the aesthetics of the globalized elite in an intense global competition to attract capital, talents, and visitors. However, the natural and cultural characteristics of the site itself have changed. In the case of the Dasha River, the hydrological environment was altered through engineering techniques to meet changed societal. This alteration is reflected not only in the channelization but also in the construction of ecologically recreative corridors. The Dasha River is rain-​dependent, with runoff concentrated in the rainy season. Nevertheless, after the river became part of the city’s landscape corridor, large investments in artificial water replenishment projects transformed the temporary stream into a permanent river (Talamini et al., 2017). Meanwhile, international firms’ production of riverfront spaces has conceived a homogenized landscape and an international lifestyle, which may overshadow local cultural characteristics and may not necessarily align with the everyday life of local people. By employing the hydrological perspective to analyze the water management process in the GBA, this chapter emphasizes that water management requires a holistic approach that considers the dynamics of hydrology and society rather than only treating water management as a technical field that relies on infrastructure provision and scientific knowledge. Shenzhen Water Strategy 2035 is China’s first attempt to use a systematic and comprehensive strategy for solving water problems. 12.10 Conclusion Rivers have often been associated with the fate of cities: the water flowing in their meanders is life-​giving and life-​threatening. Nevertheless, the role of rivers has

The production of hydrosocial space in contemporary China  217 radically changed during the rapid urban growth and industrialization of modern times. In China and other parts of the planet, urbanization has led to the severe water pollution of urban rivers, with deleterious effects on urban inhabitants’ quality of life. At the same time, the development of cities also provided technical and economic resources to tackle water pollution and respond to societal demands for spaces of leisure and recreation. Ultimately, this chapter focused on the GBA of China to provide evidence of the radical transformation of river management, from pollution control to the shaping of a new water culture. Findings from a corpus-​assisted discourse analysis of policies and newspaper articles provided evidence that such a transformation was reflected in and shaped by societal values. Finally, the case of the Dasha River provided further insights into the practical steps put forward to control flooding, reduce pollution, and, finally, construct an ecological corridor for different forms of life. Thus, the river completed its transformation from a natural seasonal stream to an ecologically enhanced complex artificial system where reclaimed water is used as a permanent landscape feature and higher-​education students and white-​collar workers gather in their leisure time for recreational purposes. Still, in such a process, a loss of cultural landscapes has occurred. Planning decisions in the early phases of urbanization also undermined future development potentials. From the case of the Dasha River, then, the following critical practical lessons for developing urban regions emerge: combined sewers must be systematically avoided, and physical space must be preserved along the river course to allow for the future integration of nature-​based solutions in stormwater management and possibly the reintegration of urban farming. Thus, urban rivers’ ecological and social potential will be made available to future generations. Acknowledgments This work was supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (Project No. CityU 21614719). We thank Mr. Zonghao Chen for granting us permission to use his bird photographs of Dasha River before and after rehabilitation. We also thank Yuxiao Li for his help with the maps and news collection; Yinjie Ma and Kehui Zhai for their assistance in developing the dataset. References Cai, S. (2020). Practice and thinking on ecological landscape construction of Dasha River in Shenzhen. Landscape Architecture Practice, 4(42), 46–​51. Carson, R. (1962). Silent spring. Penguin Books. Chen, Yi. (2022). The history of urban planning in Shenzhen. China Social Sciences Press. Chen, Y., Zhang, Z., Du, S., Shi, P., Tao, F., & Doyle, M. (2011). Water quality changes in the world’s first special economic zone, Shenzhen, China. Water Resources Research, 47(11), W11515.

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13 Water accessibility Information failures and beyond Harisankar Krishnadas and Kristina Matysik

13.1 Introduction Information failures can pose significant challenges for sustainable water resource management. When there is an imbalance of information, with one party lacking information compared to the other party may result in market distortions (Sabbaghi and Sabbaghi 2003). Market imperfections arising from information asymmetry have the potential to influence investment decisions in the realm of sustainable water resource management (Istrate 2018). Moreover, such asymmetry can also have repercussions on the efficiency of services, pricing strategies, and the allocation of resources (Sabbaghi and Sabbaghi 2003). Water is a vital and finite resource fundamental to human survival and well-​ being. With global demand for water increasing by 600% over the past century and projections indicating that demand for fresh water will outpace supply by 40% by 2030, water scarcity has become one of the most pressing challenges facing the world today (United Nations 2019; McKinsey & Company, Inc. 2009). In the African Region, one in every three people grapples with the pressing issue of water scarcity, a problem further compounded by factors such as population growth, urbanization, and rising demands for household and industrial water usage (WHO n.d.). Northern African arid areas notably suffer from physical water scarcity, with per capita water availability falling below 1,000 m3 per person annually. Conversely, the Sub-​Saharan African region faces economic water scarcity, primarily attributed to inadequate infrastructure, despite having a considerably higher per capita water availability when compared to the northern regions (UNECA 2011). Effective water resource management is thus crucial for meeting basic needs, advancing development goals, and supporting industries such as agriculture, all while ensuring long-​term sustainability. The paper conducts a two-​level analysis of water resource management in the developing world. The first level examines a technology-​financing solution in sub-​Saharan Africa, evaluating the information failure operating within the context of the intervention, and the second level discusses related interventions to identify other failures across the broader water accessibility landscape. DOI: 10.4324/9781003437833-13

Water accessibility: information failures and beyond  221 13.2  Water tank adoption in Kenya 13.2.1 Background

Sub-​Saharan Africa (SSA) suffers from economic water scarcity; chronic underinvestment in infrastructure and inadequate management of water resources has left more than 76% of the population without access to safe drinking water (United Nations 2019). Although the region has significant untapped potential in terms of groundwater and hydropower resources, smallholder farmers, who make up 60% of the population, still face challenges in accessing water. Groundwater reserves alone can supply 130 liters of drinking water per person per day, and the region boasts an installed hydropower capacity estimated at 30.4 GW, equivalent to powering roughly 10 million American households annually (Korkovelos et. al 2018; McKinsey 2019). These farmers predominantly rely on rainfall for irrigation, and many cannot afford technologies to harvest rainwater or manage water resources (Rockstrom and Falkenmark 2015). One potential solution is the increased adoption of newer technology water tanks, which can help farmers store rainfall and manage water more efficiently. Between 2009 and 2012, Innovations for Poverty Action (IPA) implemented an intervention aimed at facilitating water tank adoption among select dairy farmers in Kenya (IPA 2014). The following section discusses the IPA intervention in detail and evaluates the underlying market failure at play. 13.2.2 Intervention

The goal of the IPA intervention is to improve smallholder dairy farmers’ access to credit in the form of asset-​collateralized loans on the take-​up of rainwater harvesting tanks (the target population consists of smallholder dairy farmers with 1-​3 cows.). While 32% of farmer households within the intervention have access to piped, but highly intermittent, water, the target population (Kenya’s Central and Rift Valley provinces) spends up to 10 hours per week taking cows to a water source. Moreover, the farmers are aware of the benefits of the newer durable plastic rainwater harvesting tank. In fact, 43% already own an older, non-​durable water tank (among these tank owners, however, most own non-​durable tanks that store a limited amount of water, typically between 100–​200 liters.). Access to water is a major concern for these farmers as 32% reported losing at least one cow, and 52% reported that their cow fell sick due to drought in 2008 (IPA 2014). Because new tanks cost approximately 20% of a dairy farmer’s annual consumption, most farmers must obtain a loan to purchase the technology. Almost all farmers are familiar with the product; these lightweight, durable plastic rainwater harvesting tanks were introduced approximately ten years prior to the study. Agricultural supply dealers in the area prominently display these plastic rainwater harvesting tanks, which are the dominant choice for farmers purchasing new tanks. Since the tanks cost about $320 (or 20% of annual household consumption),

222  Urban Water Ecosystems in Africa and Asia few farmers tend to own these tanks. The high cost of tanks and stringent loan requirements are thus the primary obstacles preventing smallholder farmers from purchasing productivity-​enhancing assets. To address high costs and low loan take-​up, IPA conducted a study easing credit restrictions for smallholder farmers. In partnership with a dairy savings and credit cooperative (SACCO), IPA randomly offered loans with varying requirements, such as joint-​liability loans or deposits ranging from 4 to 25 percent of the loan to smallholder dairy farmers to purchase a water tank. This study’s SACCO is associated with the Nyala dairy cooperative, though not all dairy cooperative members are part of the SACCO. Financial cooperatives, which include SACCOs, are member-​ owned and member-​governed financial organizations. They often operate at a local level and serve the financial needs of individual members, community groups, and small firms. They are known to prioritize mobilizing savings and extending credit and play a key role in fostering social capital and local economic development (McKillop et al. 2020). The 100% collateralized loan, the main treatment, eased credit restrictions by enabling farmers to use the water tank as collateral (loan interest rates are consistent with prevailing market interest rates at the time of the study). The cooperative landscape is shown in Figure 13.1. At the time of the intervention, Kenya’s microfinance institution (MFI) credit market required farmers to provide several guarantors and a sizable deposit to secure a loan. Moreover, loans were not structured to serve small-​scale farmers with little savings and assets and often required upfront securitization as well as immediate payoff. In credit markets, fear of adverse selection and moral hazard drive creditors to increase deposit requirements and interest rates. Moreover, because repossession is most often difficult and expensive within this context, credit providers do not accept assets as collateral. Creditors’ precautions provide protection against default, but too tight of requirements result in socially suboptimal loan issuance.

Figure 13.1 Cooperative landscape.

Water accessibility: information failures and beyond  223 Table 13.1 Loan options offered Loan

Collateral

Take-​Up

Repayment Timeframe (avg)

100% cash collateralized/​ secured joint-​ liability loan 4% deposit loan

No. Deposit must cover ⅓ of the loan, remaining 2/​3rds must be insured by 3 guarantors either via savings or shares in the dairy cooperative Yes. Deposit must cover 4% ($15) of the loan Yes. Deposit must cover 25% ($90/​ 6,000KSh) of the loan Yes. Deposit of ($15) 1,000 KSh, 1 guarantor must pledge 21% (5,000 KSh) of loan

2.4%

9 months

44%

17–​22 months

28%

17–​22 months

23.5%

17–​22 months

25% deposit loan 21% guarantor loan

IPA’s solution facilitates credit expansion through asset collateralization; the tanks are large and difficult to move, and thus are relatively easy to repossess. Within the intervention, the researchers test if more accessible credit increases tank adoption as well as to what extent asset collateralization affects moral hazard and adverse selection. They offer four loan options to randomly selected farmers as shown in Table 13.1 (while loan amounts and interest rates are identical across treatment arms, security features differ). The first option reflects standard practice; its low take-​up rate (2.4%) underscores the loan’s infeasibility to most farmers. The second option, which is the aforementioned technology-​financing intervention, results in a remarkably high take-​up rate of 44%. Overall, the findings indicate that asset collateralization increases loan take-​up significantly. 13.2.3  Asymmetric information

Market failures are characterized by a socially inefficient allocation of resources. Information failure in the Kenyan credit market is the primary driver of the first intervention. Unlike other studies where the slow uptake is not mainly due to a lack of economic incentives, but a result of information, seed supply, and credit constraints, in this scenario the main barrier is lack of credit access, rather than lack of knowledge of the technology’s benefit (Shiferaw et al. 2015). The informa­ tion failure within the credit market limits credit, which ultimately hurts adoption (adverse selection, which refers to the tendency of high-​risk borrowers to seek out loans, and moral hazard, which occurs when borrowers are incentivized to take on excessive risk without the expectation of bearing the consequences of their actions, both raise the cost of borrowing.). Information asymmetry in credit markets occurs because borrowers (smallholder farmers) have more information about their riskiness than lenders. In developed countries, lenders overcome information asymmetry by requiring collateral and

224  Urban Water Ecosystems in Africa and Asia Table 13.2 Adverse selection and moral hazard Adverse Selection

Moral Hazard

Individuals who know they are likely to Borrowers exert less effort than the lender default select into the borrowing pool, would prefer and/​or take unfavorable raising default rates and interest rates in actions after an agreement. This raises the market. default rates and interest rates for the Example: a dairy smallholder farmer with a entire market (moral hazard consists high risk of default (all 3 cows are sick) of: (1) Ex-​ante: the borrower exerts less applies for a loan to purchase a water tank. effort for the project to succeed and If the farmer defaults, the SACCO must (2) Ex-​post: even if project succeeds, the raise rates or implement more stringent borrower may voluntarily default). loan requirements to prevent additional Example: a dairy smallholder farmer knows losses. the SACCO will likely seize the water tank if he or she defaults on the loan. However, the farmer also knows that the lender is unlikely to take back the water tank if the farmer only defaults on a small portion of the loan. In this situation, the SACCO is effectively subsidizing the farmers' risky behavior.

verifying borrower credit history. However, during the time of the intervention in Kenya, lenders often required guarantors and large deposits instead. This is because it is difficult to collect collateral in a developing context, and many smallholder farmers do not have a credit history. The water tank is a high-​demand asset, yet stringent borrowing rules arising from asymmetric information inhibit its adoption and implementation (the tanks hold 5,000 liters of water and can last between 17 days to six weeks, depending on usage type.). A situation in which both borrower and lender have access to all information would render deposits, guarantors, collateral, and tank valuation unnecessary in the loan provision process. Without full information, adverse selection and moral hazard lead to a suboptimal equilibrium in the water tank market. This is because lenders are more likely to charge higher interest rates, for example, to mitigate risk and cover costs. As a result, there are fewer water tanks in use, which leads to less water conservation and greater water scarcity. The intervention finds that a reduction in deposits and guarantors induces limited negative selection and moral hazard effects. In contrast, deposits and guarantor requirements have a sizable negative impact on take-​up; heavy reliance on existing screening and incentive tools appears inefficient. Moreover, lender profitability per loan does not change significantly, but increased loan demand yields higher net revenues. The costs of low take-​up clearly exceed the benefits of water tank adoption. In addition to increased water access, notable outcomes include increased girls’ school attendance, more efficient time allocation, and increased milk production. The intervention solves a last-​mile schooling problem for girls, increasing school

Water accessibility: information failures and beyond  225 attendance to 100% (though girls’ school enrollment was already universal at the time of treatment, some specifications show a 4% increase in enrollment.). Access to asset-​collateralized loans reduces household time spent retrieving water by 20%. Moreover, point estimates from survey data suggest positive but insignificant effects on milk production. Finally, in addition to the main study, a second out-​of-​sample effort in Kenya revealed similar results. These findings prompted the study’s lender to extend the program using its own resources to other programs without subsidies. Moreover, a similar program conducted by J-​PAL in Rwanda resulted in 43 (out of 160) take-​ups and only one default. Since the study, Kenya’s Equity Bank has also implemented a similar program in partnership with the tank manufacturer. 13.2.4 Limitations

While there is promising evidence that providing water tank collateralized loans can improve access to clean water for smallholder dairy farmers, several limitations are worth discussing. Firstly, this approach may not be applicable to individuals who lack a regular source of income or are not part of a savings cooperative. For example, the dairy farmer’s milk production and semi-​regular sales likely increase his or her creditworthiness. Furthermore, cooperative membership provides social support and community surveillance, which lowers the risk of default while also raising the social cost of default. Second, the approach may fail if farmers are not already aware of water tank benefits and/​or are skeptical of both the physical asset and the financial products (loans). Collateralization will incorrectly attempt to solve an information failure concerning the technology benefits. In such a case, educating farmers prior to or instead of providing collateralized loans would prove more beneficial than offering more flexible loans. Finally, the approach and its benefits are contingent upon the availability of sufficient rainfall. With little or no rainfall, the benefits may be limited or non-​existent and more farmers may default. Moreover, as weather patterns become more extreme, tanks may benefit farmers during only certain times of the year, again increasing default rates. Thus, while providing collateralized loans can improve water access for some, it is important to consider limitations prior to scaling up or implementing the approach in other contexts. 13.3  Related interventions 13.3.1  Context matters

While information failures in the credit market impede water accessibility to smallholder dairy farmers in Kenya, collateralization of all water-​related technology in sub-​Saharan Africa is unlikely to decrease economic water scarcity. This is because context matters and market failures, including but not limited to information failures, arise in more than just credit markets.

226  Urban Water Ecosystems in Africa and Asia 13.3.2  More than just information

Information failures outside of credit markets can hurt access to clean water. When households do not have access to information about the quality of their water, they are not able to make informed decisions on how to use it. In addition to being accessible, information should be understandable and actionable. A 2018 study in rural Uttar Pradesh, India, finds that household-​specific feedback on water microbiological safety can improve both behavior (water management practices) and drinking water quality. In this intervention, low-​cost water quality kits enable the provision of information pertaining to household water quality (Trent et al. 2018). The study finds that information alone yields only limited adoption of water management behaviors; abstract information about water quality without specific and actionable information is necessary but not sufficient. In this case, information coupled with education and information on low-​cost water management strategies is more effective at improving water management behaviors and water quality, which in turn leads to improved water access. 13.3.3  Relevant information and incentives

Similarly, providing information that is not relevant or useful to recipients may not motivate the recipients to take necessary action. A 2021 study in Tanzania examined the role of micro-​investing (MI) in optimizing water usage and increasing the adoption of drip irrigation for farming. Findings show that over 60 percent of MI farmers were willing to reinvest due to significant improvements in crop yield and living conditions (Bhatti et al. 2022). While the goal was water conservation, information on economic benefits was the key factor encouraging farmers to adopt new technology. These results indicate that personally relevant information may be more effective at changing behavior than general information concerning water conservation. 13.3.4  From information to action

Finally, while information can be a helpful tool for increasing water accessibility, it may not be sufficient to bring about behavior change, particularly in the long run. A 2017 intervention in Chennai, India used nudging techniques to reduce water wastage; the intervention included personal appeals to households, information cards on electricity savings and water shortage, and reminder stickers. The study found that nudging was 470 percent more effective than traditional information campaigns. Results showed that compared to pre-​study usage, water consumption by the treatment group declined by over ten percent, whereas that of the control group declined by only 1.89 percent. The specific target being nudged also influenced the study’s effectiveness. Nudging efforts targeted students, who then influenced adults and other family members within their household. The findings show a coefficient of 9688.68 liters/​

Water accessibility: information failures and beyond  227 month in the treatment group, and a coefficient of 1734.75 liters/​month in the control group, resulting in a difference in difference of 7953.93 liters in average water consumption. The results are highly significant (p