Urban Flooding in Brazil 3031208978, 9783031208973

Table of contents :
Acknowledgements
Contents
Contributors
Part I: Urban Flooding: Conceptions and Approaches in the Scope of Global Climate Changes
Chapter 1: Urban Floodings: Conceptions and Challenges in the Scope of Global Climate Change – A Look at the City of São Paulo, Brazil
1.1 A Historical and Very Current Problem!
1.2 Study Concepts, Methods, and Techniques
1.3 Present and Future Scenarios: What Does Global Climate Change Tell Us?
1.4 Notes on Flooding in the City of São Paulo, Brazil
References
Chapter 2: Intra-urban Spatial Configuration and Hydrological Responses Spatially Distributed in Basins: Contributions to a Sustainable Development
2.1 Floods and Urban Water Dynamics
2.2 The Heterogeneity of Intra-urban Spaces
2.2.1 Urban Configuration and Hydrologic Similarity Areas in the Belém Catchment, Curitiba, State of Paraná
2.3 Water Balance of Hydrologic Similarity Areas in the Belém Catchment
2.4 Nature-Based Solutions and Sustainable Urban Development
References
Chapter 3: Blue-Green Infrastructure in Brazilian Cities: From Consensus to Specific Advances
3.1 Introduction
3.2 Blue-Green Infrastructure and Its Attributes
3.3 BGIs in the International Scenario: Three Selected Countries
3.4 BGIs in the Scenario of the Ten Largest Brazilian Cities
3.5 Concluding Remarks
References
Chapter 4: Local-Scale Disaster Risk Indicators: Applying the Disaster Risk Indicators in Brazil (Drib) Method to Understand Flood Risks in Brazil
4.1 Introduction
4.1.1 Area Characterization
4.2 Methodology
4.2.1 The Concept of the Local DRIB Index
4.2.2 Research Steps
4.2.2.1 Step 1
4.2.2.2 Step 2
4.2.3 Data and Methods
4.2.3.1 Questionnaire Development
4.3 Results and Discussion
4.3.1 Exposure
4.3.2 Vulnerability
4.3.3 Risk
4.4 Concluding Remarks
References
Part II: Flooding Events in Major Brazilian Cities and Their Metropolitan Regions
Chapter 5: Urban Climate Risk: Flooding Events in Rio De Janeiro (RJ) from the Perspective of Vulnerable People
5.1 Introduction
5.2 Vulnerability Dimensions and the Homeless Population
5.3 Analysis of Urban Flooding from the Perspective of Vulnerable People: The Homeless Population in Downtown Rio de Janeiro (RJ)
5.4 Concluding Remarks: Climate as a Risk and Space as a Condition
References
Chapter 6: Urban Flooding in the City of Belo Horizonte, Southeastern Brazil
6.1 Introduction
6.1.1 Geoecological and Climatic Factors
6.2 Tensions and Hydrological Disasters in the Arrudas and Onça Stream Basins
6.3 Belo Horizonte: The City Between the Traditional and the Modern in the Flood Management Policy
6.4 Concluding Remarks
References
Chapter 7: Rainfall Impacts and (Re)Production of Urban Space in the City of Salvador, Northeastern Brazil: An Update
7.1 Introduction
7.2 The Spatiotemporal Relationship of Urban Flooding in Salvador
7.3 The Relationship Between Climate and Production of Space
7.4 Concluding Remarks: Impact as a Measure of Urban Recreation
References
Chapter 8: Urban Flooding in Fortaleza, Northeastern Brazil: Current and Future Risks and Challenges
8.1 Introduction
8.2 Environmental Systems and Occupation of Fortaleza’s Territory
8.3 Urban Flooding in Fortaleza: A Brief History
8.4 Flood Risk Mapping in Fortaleza
8.4.1 Natural Vulnerability to Floods and Storm Surges
8.4.2 Social Vulnerability
8.4.3 Flood and Storm Surges Risks
8.5 Current and Future Challenges
8.6 Concluding Remarks
References
Chapter 9: Flood Events in the City of Recife, Northeastern Brazil: History and Contemporary Risks
9.1 Introduction
9.2 Recife’s Physical Characteristics and Its Susceptibility to Flooding
9.3 Historiography of Occupation and Socio-environmental Indicators in Recife
9.4 Flood Events in Recife
9.5 Meteorological Weather Types and Their Association with Rainfall in Recife
9.6 Flood Events in Recife: Current and Future Scenarios
9.6.1 Current Scenario
9.6.2 Future Scenarios
9.7 Concluding Remarks
References
Chapter 10: Urban Faces of Climate and Floods in Aracaju, Northeastern Brazil
10.1 Introduction (Sectored Conjectures)
10.2 Theoretical Experimentation: Defining Reason
10.3 Practical Manipulation: Significance and Spatial Configuration
10.4 The Climate of Aracaju
10.5 Extreme Flood Events
10.6 Concluding Remarks
References
Chapter 11: Urban Flooding in Manaus, Northern Brazil: Extreme Events, Susceptibility, and Inequalities
11.1 Introduction
11.2 Historical Approach and Contradictions in the Urban Space of Manaus
11.3 Flood Susceptibility Associated with Extreme Rainfall Events
11.4 Flood Diagnosis in Manaus: Different Scales and Times
11.5 Present and Future Challenges
11.6 Concluding Remarks
References
Chapter 12: Urban Flooding in Porto Velho: Infrastructure, Regulatory, and Socio-environmental Conditions
12.1 Introduction
12.2 Historical Approach to the Problem
12.2.1 Historical Context of the Regulatory Instruments of Urban Occupation in Brazil
12.2.2 Regulatory Actions to Prevent Floodings in Porto Velho
12.3 Current Events
12.4 Present and Future Challenges
12.5 Concluding Remarks
References
Chapter 13: Urban Flooding in the City of Goiânia, Central-Western Brazil
13.1 Introduction
13.2 Geo-environmental Characterization and Flood-Related Processes in Goiânia
13.2.1 The Relationship Between Relief, Soil, Rock, and Physical and Natural Conditioning Factors for Flood-Related Processes
13.2.2 Climate and Flood-Related Processes
13.2.3 History of the Flood-Related Processes
13.3 Diagnosis, Vulnerability, and Neighborhoods at Risk of Flooding in Goiânia
13.3.1 Rainfall and Flooding
13.3.2 Slope Configurations and Flood Events
13.3.3 Soil Sealing and Flood-Related Processes
13.3.4 Current Vulnerability and At-Risk Neighborhoods
13.3.5 Flood-Related Challenges
13.4 Concluding Remarks
References
Chapter 14: Geographic Analysis of Flooding in the Urban Area of the Federal District, Brazil
14.1 Introduction
14.2 Historical Approach to the Problem
14.3 Analysis of Current Flooding in the Federal District Urban Area
14.4 Areas Critical to Flooding
14.5 Present and Future Challenges
14.6 Concluding Remarks
References
Chapter 15: Flood Events in the Metropolitan Region of Curitiba, Southern Brazil: An Approach from the Urban Environmental System
15.1 Introduction
15.2 The History and Challenges of Studies on Urban Flooding in Curitiba and Its Metropolitan Region
15.3 The Urban Environmental System and Its Application for Understanding Urban Flooding
15.4 Flood Adaptation Measures in the MRC: Approaches for Curitiba and Pinhais
15.4.1 Input: Extreme Rainfall Events and the Physical-Natural Attributes of Hydrometeorological Risks
15.4.2 Attributes: The Social Instances Related to Urban Flooding
15.4.3 Output and Applications: Urban Flooding and Adaptation Measures
15.5 Concluding Remarks: Present and Future Challenges of the Urban Flooding Problem in the MRC
References
Chapter 16: Urban Climate and Flooding in Florianópolis, Southern Brazil
16.1 Introduction
16.1.1 Urban Climate and Its Relation to Floods
16.2 Conditioning Factors of Floods in Florianópolis
16.3 The Origin of Urban Floods in Florianópolis
16.4 Concluding Remarks
References
Part III: Flooding Events in Medium and Small Cities in Brazil
Chapter 17: Climate Dynamics and Urban Flooding in the City of Guarapuava, Southern Brazil
17.1 Introduction
17.2 Historical Approach to the Problem
17.3 Flood Disasters Resulting from Adverse Atmospheric Conditions in Guarapuava
17.4 Assessment of Flood-Inducing Weather Events in Guarapuava
17.4.1 Climate Dynamics in Guarapuava
17.4.2 Regional Atmospheric Dynamics in Periods of Extreme Rainfall Events
17.4.2.1 Analysis of May 28, 1992
17.4.2.2 Analysis of April 23, 1998
17.4.2.3 Analysis of November 1, 2007
17.4.2.4 Analysis of August 1, 2011
17.4.2.5 Analysis of June 21, 2013
17.4.2.6 Analysis of June 7, 2014
17.4.2.7 Analysis of October 31, 2015
17.4.2.8 Summary of Analyzed Events
17.5 Concluding Remarks
References
Chapter 18: Structural and Non-structural Measures for Urban Drainage: A Look at Socio-environmental Risks of Urban Flooding in Francisco Beltrão, Southern Brazil
18.1 Introduction
18.2 Urban Water Management and the Socio-environmental Risks Associated with Floods
18.3 Structural and Non-structural Urban Drainage Measures
18.4 Drainage and Flood Control Measures Adopted in the City of Francisco Beltrão
18.5 Drainage Systems Under the Perspective of Mapping the Urban Flood Risk Areas in Francisco Beltrão
18.6 Concluding Remarks
References
Chapter 19: Rainfall Thresholds Triggering Water Crises in the Urban Drainage Network of Chapecó, Southern Brazil: Contributions to Risk Management
19.1 Introduction
19.2 Chapecó, SC: Historical and Current Configuration of Urban Flooding
19.3 Extreme Rainfall Thresholds and Water Crises in the Urban Drainage Network of Chapecó, SC
19.3.1 Possibilities and Limits for the Use of Rainfall Thresholds Triggering Water Crises in Chapecó, SC
19.4 Concluding Remarks
References
Chapter 20: Climate Dynamics and the Main Urban Flood Events in Itajaí Valley, Southern Brazil
20.1 Introduction
20.1.1 Flood Events in the Itajaí Valley
20.2 Materials and Methods
20.3 Results and Discussion
20.3.1 Climate Dynamics and Floods in Itajaí Valley
20.3.2 The Unusual Event of 2008 and Urban Flooding in Blumenau and Itajaí
20.4 Concluding Remarks
References

Citation preview

Francisco Mendonça Ariadne Farias Elaiz Buffon   Editors

Urban Flooding in Brazil

Urban Flooding in Brazil

Francisco Mendonça  •  Ariadne Farias Elaiz Buffon Editors

Urban Flooding in Brazil

Editors Francisco Mendonça Federal University of Paraná Curitiba, Paraná, Brazil Elaiz Buffon Pontifical Catholic University of Paraná Curitiba, Paraná, Brazil

Ariadne Farias Higher Institute of Business and Economics (ISAE) Curitiba, Paraná, Brazil

ISBN 978-3-031-20897-3    ISBN 978-3-031-20898-0 (eBook) https://doi.org/10.1007/978-3-031-20898-0 © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

We dedicate this work to the institutions and social movements that work in relief actions and prevention of the impacts of natural disasters in Brazil and in the world. In a special way, we dedicate this book to the population affected by urban flooding and to all those who contribute to disaster risk reduction.

Acknowledgements

We thank the Brazilian institutions that supported the development of the studies presented here: CNPQ  – National Council for Scientific and Technological Development, CAPES  – Coordination for the Improvement of Higher Education Personnel, and public Universities in Brazil. We also thank, especially, the researchers who contributed to the elaboration of this book.

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Contents

Part I Urban Flooding: Conceptions and Approaches in the Scope of Global Climate Changes 1

Urban Floodings: Conceptions and Challenges in the Scope of Global Climate Change – A Look at the City of São Paulo, Brazil����������������������������������������������������    3 Francisco Mendonça

2

Intra-urban Spatial Configuration and Hydrological Responses Spatially Distributed in Basins: Contributions to a Sustainable Development ����������������������������������������������������������������   21 Juliana Wilse Landolfi Teixeira de Carvalho and Irani dos Santos

3

Blue-Green Infrastructure in Brazilian Cities: From Consensus to Specific Advances ��������������������������������������������������   39 Demian da Silveira Barcellos and Clovis Ultramari

4

Local-Scale Disaster Risk Indicators: Applying the Disaster Risk Indicators in Brazil (Drib) Method to Understand Flood Risks in Brazil������������������������������������������������������   63 Lutiane Queiroz de Almeida, Elza Edimara Soares da Silva, Francisca L. Sousa de Oliveira, and Dyego Freitas Rocha

Part II Flooding Events in Major Brazilian Cities and Their Metropolitan Regions 5

Urban Climate Risk: Flooding Events in Rio De Janeiro (RJ) from the Perspective of Vulnerable People������������������������������������   85 Antonio Carlos da Silva Oscar Júnior, Ana Maria de Paiva Macedo Brandão, Luisa Pilar Marques Martins, and Rafaela Torres de Almeida

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 6 U  rban Flooding in the City of Belo Horizonte, Southeastern Brazil����������������������������������������������������������������������������������  107 Wellington Lopes Assis, Antônio Pereira Magalhães Junior, and Frederico Wagner de Azevedo Lopes  7 R  ainfall Impacts and (Re)Production of Urban Space in the City of Salvador, Northeastern Brazil: An Update��������������������  133 Paulo Cesar Zangalli Júnior, Denise Silva Magalhães, and Neyde Maria Santos Gonçalves  8 U  rban Flooding in Fortaleza, Northeastern Brazil: Current and Future Risks and Challenges��������������������������������������������  151 Maria Elisa Zanella, Jander Barbosa Monteiro, and Joao Luís Sampaio Olímpio  9 F  lood Events in the City of Recife, Northeastern Brazil: History and Contemporary Risks����������������������������������������������������������  171 Ranyére Silva Nóbrega, Cristiana Duarte Coutinho, Anderson Pereira Lino, and Lucas Suassuna de Albuquerque Wanderley 10 U  rban Faces of Climate and Floods in Aracaju, Northeastern Brazil ��������������������������������������������������������������������������������  193 Josefa Eliane Santana de Siqueira Pinto, Max Anjos, and João Luiz Santana Brazil 11 U  rban Flooding in Manaus, Northern Brazil: Extreme Events, Susceptibility, and Inequalities����������������������������������  209 Natacha Cíntia Regina Aleixo, Marcela Beleza de Castro, and João Cândido André da Silva Neto 12 U  rban Flooding in Porto Velho: Infrastructure, Regulatory, and Socio-­environmental Conditions ����������������������������������������������������  231 Rafael Rodrigues da Franca, Marco Bruno Xavier Valadão, and Fabiana Piontekowski Ribeiro 13 U  rban Flooding in the City of Goiânia, Central-Western Brazil���������������������������������������������������������������������������  249 Gislaine Cristina Luiz and Patrícia de Araújo Romão 14 G  eographic Analysis of Flooding in the Urban Area of the Federal District, Brazil������������������������������������������������������������������  275 Ercília Torres Steinke, Valdir Adilson Steinke, and Rafael Rodrigues da Franca 15 F  lood Events in the Metropolitan Region of Curitiba, Southern Brazil: An Approach from the Urban Environmental System����������������������������������������������������������������������������  297 Elaiz Buffon and Gabriela Goudard

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16 U  rban Climate and Flooding in Florianópolis, Southern Brazil����������������������������������������������������������������������������������������  319 Lindberg Nascimento Júnior and Geisa Silveira da Rocha Part III Flooding Events in Medium and Small Cities in Brazil 17 C  limate Dynamics and Urban Flooding in the City of Guarapuava, Southern Brazil������������������������������������������������������������  339 Aparecido Ribeiro de Andrade, Leandro Redin Vestena, and Paulo Nobukuni 18 S  tructural and Non-structural Measures for Urban Drainage: A Look at Socio-­environmental Risks of Urban Flooding in Francisco Beltrão, Southern Brazil��������  369 Ariadne Farias and Nayana Machado 19 R  ainfall Thresholds Triggering Water Crises in the Urban Drainage Network of Chapecó, Southern Brazil: Contributions to Risk Management������������������������������������������  397 Andrey Luis Binda and Elaiz Buffon 20 C  limate Dynamics and the Main Urban Flood Events in Itajaí Valley, Southern Brazil��������������������������������������������������������������  419 Wilson Flavio Feltrim Roseghini and Pedro Augusto Breda Fontão

Contributors

Ana Maria de Paiva Macedo Brandão  Doctor in Physical Geography from the University of São Paulo. She is a retired associate professor from the Federal University of Rio de Janeiro. CV: http://lattes.cnpq.br/1824293102476623 Anderson  Pereira  Lino  Doctor in Geography at The Federal University of Pernambuco, UFPE. Teacher on UFR – Federal University of Roraima. CV: http://lattes.cnpq.br/9580237473652410 Andrey Luis Binda  PhD in Geography from the Federal University of Rio Grande do Sul (UFRGS). Teacher Geography in Universidade Federal da Fronteira Sul. CV: http://lattes.cnpq.br/4363062466349516 Antonio  Carlos  da  Silva  Oscar  Júnior  Doctor in Geography from UNICAMP. Teacher at the Department of Physical Geography of UERJ. He is also the coordinator of the LISA/UERJ research group (Laboratory of Studies on the Society-Atmosphere Interaction). CV: http://lattes.cnpq.br/8105156455338202 Antônio  Pereira  Magalhães  Junior  Doctor in Sustainable Development at Universidade de Brasilia (UnB), with part of the studies carried out at Ecole Nationale des Ponts et Chaussées (Paris). Post-Doctor at the Department of Geography at the Universitat Autònoma de Barcelona. Teacher at the Department of Geography at UFMG. CV: http://lattes.cnpq.br/4282669608406708 Aparecido Ribeiro de Andrade  PhD in Geography from the Federal University of Paraná (UFPR). Teacher at the Department of Geography at the Midwestern Paraná State University (UNICENTRO). CV: http://lattes.cnpq.br/2332414893974650

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Contributors

Ariadne  Farias  Doctor in Environment and Development from the Federal University of Paraná (PPGMade/UFPR), professor and researcher in the Postgraduate Program in Governance and Sustainability (PPGS/Professional Master’s), at the Mercosur Institute of Administration and Economics (ISAE/Curitiba). She is a volunteer at the Civil Defense and Protection Coordination of the state of Paraná (CEPDEC/PR). CV: http://lattes.cnpq.br/1799068285417986 Clovis  Ultramari  Doctor in Environment and Urban Development from the Federal University of Paraná. Teacher at UFPR and Pontifical Catholic University of Paraná. CV: http://lattes.cnpq.br/5999977664359723 Cristiana  Duarte  Coutinho  Doctor in Geography at The Federal University of Pernambuco, UFPE.  Teacher on UFPE  – Federal University of Pernambuco. Geography. CV: http://lattes.cnpq.br/1311925500655287 Demian da Silveira Barcellos  Master’s in Urban Management from the Pontifical Catholic University of Paraná (Postgraduate Program in Urban Management), with stage internship at Glasgow Caledonian University/UK, and doctoral student in the same program, with stage internship at Deakin University/Australia. CV: http://lattes.cnpq.br/7223117894053703 Denise Silva Magalhães  Doctor in Geography at UFBA – Federal University of Bahia. Teacher at the Department of Geography of UFBA. CV: http://lattes.cnpq.br/3975238121738922 Dyego  Freitas  Rocha  Master’s in Development and Environment at UFRN  – Federal University of Rio Grande do Norte. CV: http://lattes.cnpq.br/4493725305783482 Elaiz Buffon  Doctor in Geography at the Federal University of Paraná (UFPR). From 2014 to 2020, she was a researcher at UFPR’S Climatology Laboratory (Laboclima). She is currently a post-doctoral researcher in the Urban Management program at the Pontifical Catholic University of Paraná (PUCPR). CV: http://lattes.cnpq.br/4599945387715185 Elza Edimara Soares da Silva  Master’s in Geography at the Federal University of Rio Grande do Norte (UFRN). Technician in Geology and Mining at the Federal Institute of Education, Science, and Technology of Rio Grande do Norte (IFRN). CV: http://lattes.cnpq.br/6298501453634781 Fabiana  Piontekowski  Ribeiro  PhD in Forest Sciences with an emphasis in Nature Conservation at the University of Brasilia (2018). Teacher, Researcher and Collaborator of the Graduate Program in Forest Sciences. CV: http://lattes.cnpq.br/8642184241182117

Contributors

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Francisca L. Sousa de Oliveira  Doctor in Geography at UECE. Coordinator of the Geoprocessing, Vulnerability, and Disaster Risk Reduction – GeoDesastre Study Group in the Geoprocessing and Applied Studies Laboratory (LabGeo – UECE). CV: http://lattes.cnpq.br/3841126728462002 Francisco Mendonça  Doctor in Geography at São Paulo University (USP). Post-­ doctor in Urban Climate (Université de Sorbonne/Paris, Université de Haute Bretagne/France and Universidad de Chile) and Climate and health (London School of Hygiene and Tropical Medicine). Teacher at Federal University of Paraná (UFPR) and State University of Rio de Janeiro (UERJ). He was president of ABClima (Brazilian Association of Climatology) and AIC (International Association of Climatology) and member of CoC-UGI (Commission of Climatology – International Geographical Union). Member of Scientific Committee of CEMADEN – Brazilian Center for Prevention of Natural Disasters. CV: http://lattes.cnpq.br/3941384182506697 Frederico Wagner de Azevedo Lopes  Doctor in Geography and Environmental Analysis from UFMG, with a stage period and post-Doctorate at the National Institute of Water and Atmospheric Research (NIWA) – New Zealand. Teacher at the Department of Geography at UFMG. CV: http://lattes.cnpq.br/6024111255041334 Gabriela Goudard  Master’s in Geography (2019) at UFPR, with an internship at the Université de Moncton, Canada (2018). She is currently a doctoral student in geography at UFPR. She was a collaborating professor at the State University of Ponta Grossa (UEPG). CV: http://lattes.cnpq.br/7654015279122265 Geisa Silveira da Rocha  Doctor in Geography at the Federal University of Paraná (UFPR). She has a stage research at Université Rennes 2 (France). CV: http://lattes.cnpq.br/1431724023778991 Gislaine Cristina Luiz  Doctor in Environmental Geotechnics at the University of Brasília (UnB). Teacher at the Institute of Socio-Environmental Studies (IESA – UFG). CV: http://lattes.cnpq.br/4310433384519387 Irani dos Santos  Doctor in Geography at the Federal University of Santa Catarina (UFSC  – 2009). Teacher at UFPR and coordinator of the Hydrogeomorphology Laboratory at the same institution. CV: http://lattes.cnpq.br/5351700724990743 Jander  Barbosa  Monteiro  PhD in Geography from the Federal University of Ceará – UFC. Teacher at the State University of Vale do Acaraú. CV: http://lattes.cnpq.br/4218192054179148

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Contributors

João Cândido André da Silva Neto  PhD in Geography from the Paulista State University (UNESP)/Presidente Prudente. Teacher at the Department of Geography UFAM  – Federal University of Amazonas and coordinator of the Laboratory of Hydrogeography, Climatology, and Environmental Analysis of the Amazon. CV: http://lattes.cnpq.br/6693264591240467 Joao Luís Sampaio Olímpio  Doctor in Geography from the Federal University of Ceará (UFC). Teacher at the Federal Institute of Education, Science and Technology of Ceará (IFCE). He is the leader of the research group Nucleus for Integrated Studies in Environmental Geography, Geodiversity and Geoinformation (NIGEO). CV: http://lattes.cnpq.br/3175820625417182 João Luiz Santana Brazil  Master’s in Geography from the Federal University of Sergipe (UFS). He is currently a doctoral student in Geography at the Federal University of Sergipe-UFS. CV: http://lattes.cnpq.br/6440965737330713 Josefa Eliane Santana de Siqueira Pinto  Doctor in Climatology at UNESP/Rio Claro. Teacher at the Federal University of Sergipe. She was vice-president of ABClima – Brazilian Association of Geographical Climatology. CV: http://lattes.cnpq.br/9182673895016843 Juliana  Wilse  Landolfi  Teixeira  de Carvalho  Master’s in Geography at the Federal University of Paraná (UFPR). She is currently a doctoral student in Geography at UFPR. CV: http://lattes.cnpq.br/2256305214659602 Leandro  Redin  Vestena  PhD in Environmental Engineering from the Federal University of Santa Catarina (UFSC, 2008). Post-doctoral internship at the Institute of Hazard, Risk and Resilience at Durham University (UK). Professor at the Department of Geography at the Midwestern Paraná State University (UNICENTRO). CV: http://lattes.cnpq.br/2389916164041767 Lindberg Nascimento Júnior  Doctor at the UNESP – São Paulo State University/ Presidente Prudente. Teacher at the Geography Department of the Federal University of Santa Catarina, Florianópolis. CV: http://lattes.cnpq.br/0232412865816844 Lucas  Suassuna  de Albuquerque  Wanderley  Doctor in Geography at The Federal University of Pernambuco, UFPE.  Teacher at IFA  – Federal Institute of Alagoas. CV: http://lattes.cnpq.br/0018963581369746 Luisa Pilar Marques Martins  Bachelor’s in Geography at UERJ – Rio de Janeiro State University. CV: http://lattes.cnpq.br/1845221284139961

Contributors

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Lutiane Queiroz de Almeida  Doctor in geography at UNESP/Rio Claro. Teacher at the Department of Geography, Federal University of Rio Grande do Norte (UFRN). Coordinator of the GEORISCO – Environmental Dynamics, Risks, and Spatial Planning Research Group. Coordinator of the Interdisciplinary Center for Research on Disasters (NUPED – UFRN). CV: http://lattes.cnpq.br/7311955924979180 Marcela Beleza de Castro  Master’s degree in Geography at the Federal University of Amazonas (UFAM). CV: http://lattes.cnpq.br/6920370160603821 Marco Bruno Xavier Valadão  PhD in Forest Sciences at the University of Brasília (2019). Volunteer professor at the Geography Department of the University of Brasília. CV: http://lattes.cnpq.br/8332178120048232 Maria  Elisa  Zanella  PhD in Environment and Development at the Federal University of Paraná  – UFPR, currently Associate Teacher at Department of Geography – UFC – Federal University of Ceará. CV: http://lattes.cnpq.br/4796364766536684 Max Anjos  PhD in Physical Geography at the Institute of Geography and Spatial Planning of the University of Lisbon, Portugal. Post-doctoral researcher at the Technische Universität Berlin, Germany. CV: http://lattes.cnpq.br/2730146407492791 Natacha  Cíntia  Regina  Aleixo  PhD in Geography from UNESP/Presidente Prudente with a stage at the University of Coimbra. Teacher in Geography at the UFAM – Federal University of Amazonas. CV: http://lattes.cnpq.br/9509290240626293 Nayana  Machado  Bachelor’s degree in Environmental Engineering from the Pontifical Catholic University of Paraná (PUCPR) and Master’s student in Environ­ mental Engineering at the Federal University of Paraná (PPGEA/UFPR). Researcher at the Technology and Environmental Monitoring System of Paraná (SIMEPAR). CV: http://lattes.cnpq.br/0464597257601943 Neyde  Maria  Santos  Gonçalves  Doctor in Geography at the University of São Paulo (USP). Currently, she is a retired professor at the Department of Geography, Institute of Geosciences, UFBA. CV: http://lattes.cnpq.br/6522136063276119 Patrícia  de Araújo  Romão  Doctor in Geotechnics at the University of Brasília (UnB). Teacher at the Institute of Socio-Environmental Studies (IESA) of the Federal University of Goiás (UFG). CV: http://lattes.cnpq.br/0188184635964559

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Contributors

Paulo  Cesar  Zangalli  Júnior  Doctor in Geography from São Paulo State University (UNESP/Presidente Prudente). Teacher at Federal University of Bahia (UFBA). CV: http://lattes.cnpq.br/5876431730474050 Paulo  Nobukuni  Master’s in Soil Science from UNESP, Campus Jaboticabal. Doctoral student in Geography in the Post-Graduate Program at Midwestern Paraná State University (UNICENTRO). He is currently a teacher at the Geography Department of UNICENTRO. CV: http://lattes.cnpq.br/4440485848408171 Pedro Augusto Breda Fontão  Doctor in Geography at UNESP/Rio Claro. Teacher at the Department of Geography of the Federal University of Paraná (UFPR). CV: http://lattes.cnpq.br/7615025096908509 Rafael  Rodrigues  da Franca  PhD in Geography at the Federal University of Paraná (2015). Teacher at the Department of Geography at University of Brasília (UnB). CV: http://lattes.cnpq.br/2530058025139960 Rafaela Torres de Almeida  Undergraduate student in Geography at UERJ – Rio de Janeiro State University. CV: http://lattes.cnpq.br/4113192131074003 Ranyére  Silva  Nóbrega  Doctor in Meteorology. Teacher at UFCG  – Federal University of Campina Grande. Participates in the Graduate Program in Geography at UFPE  – Federal University of Pernambuco. Participated in the Postgraduate Program in Teaching Environmental Sciences at UFPE. CV: http://lattes.cnpq.br/9860653777047562 Wellington Lopes Assis  Doctor in Geography and Environmental Analysis from the Federal University of Minas Gerais (UFMG). Teacher at the Department of Geography at UFMG. CV: http://lattes.cnpq.br/7319113418076858 Wilson  Flavio  Feltrim  Roseghini  Doctor in Geography from the Federal University of Paraná (UFPR), attending two semesters at Columbia University/ USA. Teacher at the Department of Geography at UFPR. CV: http://lattes.cnpq.br/2169966917320531

Part I

Urban Flooding: Conceptions and Approaches in the Scope of Global Climate Changes

Chapter 1

Urban Floodings: Conceptions and Challenges in the Scope of Global Climate Change – A Look at the City of São Paulo, Brazil Francisco Mendonça

Abstract  Urban floods have historically occurred in most countries of the world. They are more expressive, in quantity and intensity, in cities located in areas dominated by humid climates. Urban floods express a combination of rainfall (climate) and flat relief, and, in cities, they are strongly intensified due to processes of an anthropogenic nature (especially in the Anthropocene) and global climate change. In the countries of the global South, the impacts associated with floods are very expressive, mainly due to the conditions of poverty and negligence of the public authorities in their occurrence. Under these conditions, the risks to urban floods are potentially high due to the high socio-environmental vulnerability of the populations. The city of São Paulo, Brazil, which records alarming episodes of floods, illustrates the theme discussed here. The present book brings a set of texts that address conceptual, methodological, and technical aspects of urban floods, in its first part, followed by studies of the phenomenon in cities, metropolitan areas, and large and small cities in Brazil. The very prospect of urban flood disasters has major socio-political consequences. Consequences, however, that are often lost in the blind spots of “technical” analysis. (...) ... the distribution of urban flood risks also exacerbates already glaring global sociomaterial inequalities (Beck, 2016); while major engineering works are currently being executed to make lower Manhattan “climate-proof,” these resources are non-existent for vulnerable urban communities in the global South. (Beck, 2016, p. 220)

F. Mendonça (*) Federal University of Paraná, Curitiba, Paraná, Brazil © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 F. Mendonça et al. (eds.), Urban Flooding in Brazil, https://doi.org/10.1007/978-3-031-20898-0_1

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1.1 A Historical and Very Current Problem! As of the beginning of 2022, several Brazilian cities are being impacted by heavy flooding. This is a historically recurring phenomenon, with growing intensity not only in Brazil but practically all over the world. The greatest recurrence, intensity, and impacts of floods, however, are registered in countries whose geography is characterized by rainy climates, relief with sizeable flat terrain, and large contingents of populations living in poverty or misery, that is, countries from the global South, as Beck points out in the epigraph above. The geography of floods reveals the elements and factors of the nature of the places (climate and relief) and aspects of society (economy, politics, and culture), hence conceiving the phenomenon as being of an eminently socio-environmental nature. Floods occur episodically, or even rarely, and less intensely in places situated under temperate humid or dry climates, whereas in countries under humid and hot climates, they are generally very recurrent and impactful. There are several causes related to the occurrence of urban floods, mainly rainfall (concentrated or sparse), topography (flat terrain) and the type of soil cover (sealing, among others), disposal of solid waste on the surface, failures in infrastructure projects (inadequate and/or insufficient drainage), buildings in risk areas, and inattention to planning and urban management that takes into account the environmental dimension in the cities’ urbanization process. The Federative Republic of Brazil is made up of 5570 cities that have relative administrative autonomy, as they make up the third hierarchical level of deliberation within the nation, below the states and the Federal Government. Most Brazilian cities have an urban site with high susceptibility to urban flooding; that is, they are located in places with a humid climate, flat topography, and chaotic and poverty-­ stricken urbanization. These features permanently contribute to the increasingly intense annual record of urban flooding in the country, which intensifies the magnitude of the phenomenon and increases the number of victims, whether in terms of people’s lives, ecosystems, or the economy of places. Between the 1950s and the 1970s, Brazil registered a significant demographic transition: the country’s rural population, predominant thus far—a context that corroborated the country’s economic profile as an agricultural and poorly mechanized country—was overtaken by the urban population. From the 1960s on, Brazil’s urban population grew dramatically (it is approximately 85% of the country’s population today), resulting, among other things, in changes in the agricultural production pattern and in the mechanization of the countryside. In addition to holding a strong appeal through governmental actions, the cities represented then the possibility of a better life, progress, and modernity for the migrant population. The absence of planning that would direct the overwhelming rural exodus process, added to the vegetative growth of the urban population, resulted in urban swelling, which further intensified all kinds of risk in the cities. Santos (1993) called the accelerated and chaotic growth process of Brazilian cities “corporative urbanization” and indicated that it was not due to spontaneous conditions but as a result of the action of real

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estate agents who had the urban land revenue as the driving force of the relations of production in the cities. Urban flooding is closely linked to this process. The growing impact of floods on human and urban life has always been part of the Brazilian urbanization process, as they are closely related processes. The inherent pluviosity of Brazil’s tropical climate, which results in large part from the permanent displacement of humid atmospheric systems from the Atlantic and the Amazon, entails a substantial input of water into the surface systems from which, in extreme situations of positive excesses, there is water spreading. There is, therefore, a natural dimension to floods that is directly linked to the humid climates in Brazil, and that is a key element to analyze the phenomenon in the country’s context; due to the countless problems caused, it is one of the first-order problems for Brazilian society, and, as we will see below, society itself is the main genesis of the problem. As the fifth largest country in the world by area and with a population of over 210 million inhabitants, Brazil has a dense network of cities. Even though the conditions are favorable for human settlements throughout the territory, Brazilian urbanization has not been homogeneous; the irregular distribution of urban areas is the result of a historical process that favored occupation near the coasts, while the density of the Amazon forest restricted it to an area of relatively low occupation. Figure 1.1 illustrates Brazilian urbanization according to data from the Brazilian Institute of Geography and Statistics (IBGE, acronym in Portuguese) for 2021; we can clearly see the concentration of humans and cities in the eastern portion, especially the southeast, and the relative emptiness of the central and northern portions of the country. Most of the country’s urban centers, as well as the largest cities, are concentrated in the southeastern and coastal portions of Brazil. To deal with all of them, or the urban floods historically recorded in all of them, would be practically impossible in a single book. This book is composed of case studies of a few Brazilian cities, and they are only a sample of a very numerous and complex reality; in the following chapters, we will analyze the floods registered in the cities of Manaus, Porto Velho, Fortaleza, Recife, Aracaju, Salvador, Brasília, Goiânia, Belo Horizonte, Rio de Janeiro, São Paulo, Curitiba, Guarapuava, Francisco Beltrão, Chapecó, cities in the Itajaí Valley, and Florianópolis. The choice for these cities followed mostly personal criteria, i.e., they were the object of research of my doctoral students and/or research partnerships with colleagues and collaborators from research centers around the country. The theme of urban flooding is one of the main research topics in urban climatology in Brazil, and the examples are numerous; our choice criterion was guided, then, by personal and professional relationships, with the intention of shedding light on specific problems of some cities as a way to exemplify a problem that has been registered nationally and worldwide. Urban flooding is hereby approached by focusing on the dynamics of pluvial precipitation (rainfall). The choice of cities allows the reader to place them according to the country’s climatic domains (Fig. 1.2): equatorial (Manaus and Porto Velho), tropical equatorial (Fortaleza), eastern northeast tropical coastal (Recife and Aracaju), tropical humid-dry (Brasília, Goiânia, Belo Horizonte, Rio de Janeiro, and São Paulo),

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Fig. 1.1  Brazil—urban population (2021) (© Herve Thery. Source: IBGE Logiciel Cartes & Donnees – © Articque)

and subtropical humid (Curitiba, Guarapuava, Francisco Beltrão, Chapecó, Vale do Itajaí, and Florianópolis). Although most Brazilian urban floods are recorded in the long summer (October to April in the Southern Hemisphere), which is a summerconcentrated rainfall typical of the humid tropical climate, they are also recorded in the other seasons of the year, as will be seen in the following chapters.

1.2 Study Concepts, Methods, and Techniques Flash floods, floods, and inundations are common terms used to identify excess water, accumulated or in motion, on the planet’s surface. These terms have quite distinct connotations, although they are used in everyday language without much precision and are fraught with substantial polysemy. We must first consider that flooding refers to the spreading of surface water from a water surface, that is, the overflow of rain, lake, or sea water beyond the natural

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Fig. 1.2  The climate domains of Brazil. (Adapted from Mendonça & Danni-Oliveira, 2007)

bed of rivers, lakes, or seas. From such a broad definition, various types of floods can be distinguished: those that are completely natural or those with some or total human interference. Urban flooding is distinguished from rural flooding by numerous aspects. We can highlight that, in cities, the differentiated flood processes result from a set of elements that alter the normal flow of water in streams, e.g., channel straightening, soil sealing, artificial drainage, anthropogenic water input in the system, and soil occupation and use. In rural areas there also is some human intervention in the drainage basins, such as dams on water courses and agricultural activities, mining, etc., but they are, in general, isolated processes, mainly in which the rivers occupy their larger beds, with much lower impacts when compared to urban areas.

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Because of the variety of conceptions surrounding urban flooding, we took the liberty of letting the authors in this work choose the concepts that suited their case studies. As such, the reader will be able to find a set of conceptual, methodological, and technical conceptions that underlie the studies of urban flooding in Brazil, but these are not limited to this work, since the research possibilities are quite dense and varied; those employed here respond to the context and the desire of the researchers. The studies presented here show that urban flooding results from the interaction between society and nature, since it is shaped by rainfall processes associated with relief and urbanization; it is a characteristic and exemplary phenomenon of the Anthropocene, this phase of history in which mankind has become a producer of landscapes at the most diverse scales of the globe. Flash floods and inundations also concern the relationship between water and land surface, dissociated from water courses; the former occur with moving water, while the latter result from the accumulation of water in places and for a certain time due to deficient drainage systems. There are two important differences between these phenomena and urban flooding: they do not necessarily occur in cities, nor are they necessarily connected to water courses. Although we assume that urban floods result from the interaction between nature and society, to better understand their occurrence, it is necessary to conceive them as a complex phenomenon that, due to its condition and dynamics in the city, indicates a singular condition to its approach (Fig. 1.3). The elements that constitute urban floods are rainfall (climate), relief (flat terrain), and human settlement (society) that, in close interaction, generate a strongly hybrid environment in which the separation between the natural and the social is tenuously evidenced. Urban floods are highly heterogeneous phenomena in space and time, presenting a very rich and detailed geography around the globe. This spatial and temporal differentiation is strongly influenced by the climate; the topography of the relief; the cultural, economic, and political characteristics of the different societies; the public policies; the technical-technological advances of the different human groups; etc. In other words, the elements at the genesis of urban floods (rainfall, relief, urbanization) are strongly marked by the factors that shape their distinctive occurrence on the planet. Fig. 1.3  Urban flooding: nature, society, and city intersection

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In the same way that there is a polysemy involved in the conception of urban flooding, its study employs a myriad of methods and techniques. The methods for the analysis of flooding in cities are generally the same ones from the scientific fields that conduct the studies and diagnoses; for instance, the proposals coming from the engineering field notably use quantitative methods and mathematical modeling; other fields, such as the geosciences, employ analytical models and modeling, while qualitative methods prevail in the humanities, economics, and health sciences. From the perspective of multi- and interdisciplinarity, there is always a variation or conjunction of perspectives to approach the problem of urban flooding, as the idea of complexity takes prominence under this prism. In general, studies use geoprocessing resources to represent the phenomenon by means of maps, graphs, images, schemes, tables, etc., a tool that is widely used regardless of the scientific field from which the study is conducted. The case studies in this work rely on the use of different methods and techniques, illustrating the wealth of possibilities of methodological and technical approaches to the central problem of this work. However, for the most part, each chapter analyzes one predominant characteristic of urban flood diagnoses in different realities in Brazil—aside, of course, from conceptual discussions in the first part of the work. Although they do not go into detail about structural or non-structural urban flood control measures, they provide a set of prevention and control measures for both public authorities and autonomous or mixed initiatives.

1.3 Present and Future Scenarios: What Does Global Climate Change Tell Us? Urban flooding has become an increasingly frequent problem in societies, especially in places where there has been a rapid process of urban expansion, soil sealing, and disorganized occupation, often without proper planning or structure. Regardless of the global climate changes recorded in modern times, most Brazilian cities have always registered the occurrence of floods; however, data shows that the phenomenon has intensified in the last century and tends to get much worse in future decades, in view of the intensification of extreme hydroclimatic events associated with the unbridled and frightening urbanization process in countries and continents in contexts of complex development. Although urban flooding is related to several causes and effects in the geographic space, as previously mentioned, and has the potential to affect the population in distinct ways, the importance of analyzing it from the context of global climate change and its regional and local repercussions is undeniable. It is of fundamental importance to understand this phenomenon in the context of atmosphere dynamics and its exceptionalities—especially when extreme positive rainfall events occur in cities and result in excess water on the surfaces of cities, constituting a potential risk for urban societies. Extreme positive hydroclimatic events can unfold as of slow

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duration, after several consecutive days with mild rainfall and saturation of water infiltration into the soil, or in an accelerated manner with considerable rainfall totals within minutes or hours. Given that extreme hydrometeorological events have the potential to trigger floods and inundations, investigating such processes is critical to identifying potential impacts on society and human health (Bell et al., 2018). Evidently, it is difficult to distinguish the origin and distribution of extreme weather events, a question that led Trenberth et al. (2015) to discuss, for example, the natural origin of these episodes and how representative and inherent they are to the natural variability of the climate; it was in this sense that Mendonça (2020) defined them as hybrid risks, since they do not result solely from slow or concentrated rainfall but from the interaction of these with urban contexts. For Hammond et al. (2015), it is factual that episodes of flooding and inundation can cause major disruptions in cities and have significant impacts on people, the economy, and the environment; moreover, “these impacts may be exacerbated by climate and socio-economic changes.” It is worth emphasizing that exceptional weather episodes and impacts on the urban environment can occur through complex interactions, an interaction shaped by physical drivers and societal forces (Raymond et al., 2020). In cities, these problems extrapolate their impacts to various sectors, revealing risks, vulnerabilities, and the need to approach the urban space from a socio-environmental point of view (Mendonça, 2011). In view of this, O'donnell and Thorne (2020) argue that “urban flooding is one of the key global challenges of the twenty-first century, with future flood risk being exacerbated by climate change, urbanization and aging infrastructure,” stating that “rainfall, as impacted by climate change, is the leading source driver of future urban flood risk.” Thus, to consider climate change and its possible scenarios in the analysis of the phenomenon of urban flooding is of fundamental importance for future planning and risk and vulnerability management of urban populations, in a context of adaptation and socio-environmental resilience. These considerations are found in the partial reports (and the synthesis) of the sixth generation of the Coupled Model Intercomparison Project (CMIP6), embodied in the Sixth Assessment Report (AR6) of the Intergovernmental Panel on Climate Change (IPCC, 2022), published earlier this year. Projected scenarios and possible applications in the field of climate change impacts, adaptation, vulnerability, and mitigation presented in AR6 draw attention to the much sharper and more detailed resolution than the previous version, published in 2014 (AR5 – IPCC, 2014). One of the most important statements of this report is that “a warmer climate will intensify very wet and very dry weather and climate events and seasons, with implications for flooding or drought (high confidence), but the location and frequency of these events depend on projected changes in regional atmospheric circulation” (IPCC, 2021, p. 26). Although this is a preliminary finding of the Working Group I entitled “The Physical Science Basis” (IPCC, 2021), it is a worrying projection in the context of urban flooding. The report reveals in the technical summary that: The projected increase in heavy precipitation extremes translates to an increase in the frequency and magnitude of pluvial floods (high confidence) (…) The probability of

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compound extreme events has likely increased due to human-induced climate change. Concurrent heat waves and droughts have become more frequent over the last century, and this trend will continue with higher global warming (high confidence). The probability of compound flooding (storm surge, extreme rainfall and/or river flow) has increased in some locations, and will continue to increase due to both sea level rise and increases in heavy precipitation, including changes in precipitation intensity associated with tropical cyclones (high confidence). (IPCC, 2021, p. 58)

The increased frequency and intensity of rainfall, especially heavy and concentrated rainfall, have varied considerably in the last two centuries (Fig. 1.4). Their

Fig. 1.4  Projected changes in the intensity and frequency of extreme precipitation over land. (Source IPCC, 2021)

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Type of observed change in heavy precipitation

b) Synthesis of assessment of observed change in heavy precipitation and confidence in human contribution to the observed changes in the world’s regions

Increase (19) Decrease (0)

North America

WNA

GIC

NEN

CNA

Central America

SCA

High Medium Low due to limited agreement Low due to limited evidence

CAR

SWS

SAH

NSA

WAF

NES

SES

RAR WSB

MED WCA

Small Islands

SAM South America

NEU WCE EEU

NWS

Confidence in human contribution to the observed change

Europe

ENA

NCA

Low agreement in the type of change (8) Limited data and/or literature (18)

NWN

ECA

ARP

Asia

RFE

TIB

EAS

SAS

CAF NEAF

WSAF SEAF Africa

ESB

SEA

PAC NAU

MDG

CAU

ESAF Australasia

EAU

SAU

Small Islands

NZ

SSA Type of observed change since the 1950s

Fig. 1.5  Summary of the assessment of the change in the patterns of heavy rainfall (SES southeastern South America). (Source IPCC, 2021, Figure SPM.3)

frequency has increased by about 1.3 times from the mid-nineteenth century to the present and is likely to increase by up to 2.7 times under a 4 °C global warming scenario. Their intensity, in turn, has increased by about 7% in the last century and will be more substantial in the context of global climate change, possibly reaching an intensity up to 30% higher than in the past. Both the frequency and intensity of heavy rainfall have recorded an increase in the last century; in future global warming scenarios, the trend is toward a worsening of this situation in both the optimistic and the pessimistic scenarios, although in the latter they are indeed frightening. The trends of increasing global temperatures and precipitation are part of AR6. The report concludes, as already mentioned, that climate change is affecting all inhabited regions of the planet; human influence is contributing to most of the changes observed in the atmosphere, with extreme events standing out because of their recurrence and intensification, which have increasingly been harming populations and the economy. Figure 1.5 summarizes the changes in the pattern of intense rainfall on the planet, with emphasis on a significant increase in the SES region— corresponding to the Center-South of Brazil. This area has limited data and literature regarding floods in the context of global climate change; however, the data allow us to infer that floods tend to increase and, more seriously, that the establishment of protocols to control the problem is still quite scarce. With an increasing incidence of heavy and concentrated rainfall over shorter periods of time, both on a global scale (in various parts of the world, regardless of the optimistic or pessimistic scenario of global climate change) and on a regional and local scale, it is expected that floods and inundations will be more and more frequent in Brazil. Given the complexity of the global climate change phenomenon, it appears that while heavy and concentrated precipitation tends to become more intense, its occurrence tends to decrease in some regions of the globe, as shown in Fig.  1.6; this figure also points to the causes of heavy rainfall, including those related to the cryosphere and coastal zones. In Brazil’s context, we can see that the

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Fig. 1.6  Infographic depicting important factors in determining changes in heavy precipitation and flooding. (Source IPCC, 2021 – FAQ 8.2, Fig. 1)

shortcomings of urbanization and urban planning associated with the fact that a significant portion of the population is poor and miserable—and are thus at a high stage of vulnerability to risks—suggest an intensely grave scenario of the impacts of flooding in practically the entire country, with significant economic losses and intensified morbidity and mortality among the population. As may be noted, CMIP6 projects an increase in future rainfall over southeastern South America and the northern Andes—a result that is generally consistent and in line with previous projections by CMIP3 and CMIP5 (Debortoli et  al., 2020; Almazroui et al., 2021). In view of this, extreme events such as floods, droughts, and heat waves can be expected to further escalate in the coming years as the scenarios projected in the models get closer to reality, raising the alarm for adaptation, resilience, and mitigation measures in major urban centers in Brazil, as well as in other areas of the planet.

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1.4 Notes on Flooding in the City of São Paulo, Brazil According to AR6 (IPCC, 2022), global climate change impacts populations and places around the planet in different ways, and by February 2022, “the people and ecosystems least able to cope are being hit the hardest.” The absence or insufficiency of more effective public policies aimed at climate risk management, as well as the lack of strong actions to reduce gas emissions, has reduced the resilience threshold of Earth’s biodiversity. The impacts of extreme events on urban areas have greater repercussions in terms of material damage and more significant morbidity and mortality rates among its population when compared to rural areas. As far as humans are concerned, it is already known that the impacts will be greater the more vulnerable they are to the different risks associated with climate extremes, for instance, poor and miserable populations, especially those living in floodplains and coastal areas, who are already exposed to water insecurity at critical levels. In more urbanized areas, the impacts of extreme weather events and natural hazards will not only be more severe but will also be unavoidable in the coming decades. Among the phenomena triggered by the climate, floods take prominence because, according to Amaral (2020), they “represent the natural disaster that occurs most frequently in the world.” Thus, the risk posed by flooding stands out given its magnitude in the urban space and also due to the frequency with which it has been occurring over time, especially in modernity. Floods have caused inexorable damage to human life all over the world, affecting multiple dimensions of sustainability. When looking at the financial aspects, flooding has caused $82 billion in damages worldwide in 2021 (Swiss Re Institute, 2022). In Brazil, the Federation of Commerce of Goods, Services and Tourism of the state of São Paulo estimated a loss of R$ 110 million in a single day in the city of São Paulo after a rain event in 2020, taking into account the closing of stores, displacement of employees, and the lower circulation of customers. In the global context, the hybrid risk of flooding and its consequences in the urban space is linked to three systems: hydroclimatic (excess rainfall, inefficient drainage), lithospheric (flat relief, low slope), and political-social (deforestation, solid waste, soil sealing, alteration of streams, floodplain occupation, low population awareness, ineffective public policies and management, inadequate or inefficient engineering works, among others). Each of these systems contributes, in an interrelated way, to the understanding of the genesis of risk and associated disasters. We stress that, in many cases, there are overlaps between the so-called natural risks (hazards and susceptibilities that affect populations) and social risks (differentiated access to resources and living conditions, which potentiate the impacts of floods), which confer a set of difficulties to risk analysis when they are conceived as being strictly either natural, social, or technological (Goudard & Mendonça, 2022). The combination of them, especially because the threat or danger of risk is always related to society, is what leads to conceiving them as a social condition, hence forging the concept of hybrid risk, which is fully applicable to urban flooding (Mendonça, 2020).

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In the Brazilian scenario, the city of São Paulo deserves to be highlighted, as it is the largest city in South America (more than 12 million people live in the city, and more than 30 million live in the conurbated urban area) and one of the largest urban agglomerations in the world. Its urban area extends over a dense fluvial network surface, whose main water courses are the Tietê River, the Pinheiros River, the Aricanduva River, and the Tamanduateí River. The predominant climate is high altitude tropical with rainfall throughout the year, although with greater concentration in the austral summer months. The city has recorded episodes of urban flooding throughout its history of over 400 years, which have intensified in the last century especially due to the rise of urbanization since the mid-twentieth century. For Santos (2011), in the “São Paulo capital, the problem of flooding was already a topic of discussion even before the mid-19th century, and the case of the Tamanduateí River illustrates this process.” For the author, this problem is the result of the occupation of floodplains, or várzeas, which served as natural reservoirs for the regulation of river courses during times of heavy rainfall. As occupation expanded and the technification of space intensified, floods took on larger and more impactful proportions. The urbanization process of the city of São Paulo was historically marked by legal transgressions, inefficient territorial planning, and appropriation of inadequate geomorphologic compartments for human settlements, whose original characteristics, mainly those of dissected plateaus and broad meandering plains of the humid tropical environment (Fig. 1.7), created unique and permanent risk scenarios, among them those of floods and inundations (Simas et al., 2021). In this historical context, according to Amaral and Ross (2020), with each rectified or channeled water course, new land was cleared for occupation, which occurred quickly. From the occupation of the floodplains, areas at risk of flooding were created (Fig. 1.8). Floods in the city of São Paulo have been and continue to be the subject of several scientific papers, in the most diverse areas of knowledge; however, it is worth pointing out that most researches are still limited to the river courses, not adopting the watershed as a planning unit, which could facilitate an integrated analysis. In the context of the Upper Tietê River Basin, Rodrigues (2015) discusses that the historical sequence of anthropic interventions in the plains starts mainly with mining, followed by hydraulic works (rectifications, reversals, impoundments, etc.) and other uses and interventions. If, at first, the waters were essential to the occupation of the area that would become the city of São Paulo—mainly as of the third quarter of the nineteenth century due to the wealth derived from the coffee economic complex in São Paulo and the consequent population densification—they gradually became an obstacle to the physical expansion of São Paulo and were taken as a disseminating agent of insalubrity (Santos, 2006). Luz and Rodrigues (2020) state that in the 1990s, 95.2% of the Pinheiros River fluvial plain was already taken by urbanization (including parks and urban equipment), leaving only small unoccupied spots, predominantly on low terraces. Still according to these authors, the lack of land suitable to collect flood waters during rainy periods, so frequent in São Paulo summers, has resulted in a great social and economic impact of floods in the city.

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Fig. 1.7  Pinheiros River in São Paulo: Meanders, projected rectification, and current situa­ tion. (Source: https://m.facebook.com/Geopizza/photos/a-­transforma%C3%A7%C3%A3o-­dorio-pinheiros-em-­s%C3%A3o-­paulo-­antes-­de-­sercanalizadoem-­sua-­nasc/2554897544806449/)

Rodrigues (2015), when analyzing environmental attributes in urban land planning in the metropolis of São Paulo, states that this process of urban space production has left minimal unoccupied spaces in these areas, making the region even more dependent on costly interventions and an admittedly unreal climatic regularity. Thus, the replacement of river plains that offered an environmental service of water storage by the various constructions to contain excess rainfall in extreme events—and their ineffectiveness for such purpose—has been analyzed over time, such as in Simas (2017); Rodrigues (2015); and Luz and Rodrigues (2020). Regarding climate regularity, in addition to being no longer feasible in the current scenario, future forecasts point to a greater frequency of extreme events (Zilli et al., 2017; Marengo et al., 2020; PanClima, 2021) and a reduction of mild events, i.e., to a greater variability of climate and, consequently, of rainfall (excess and scarcity) concomitant with the rising temperatures. Data from the International Disaster Database (EM-DAT, 2022) reveals that in the last 30 years (1992–2022) in Brazil, about 10 million (9,320,588) people have been affected by floods, with 3390 recorded deaths, 18% of which occurred in the last 5 years.

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Fig. 1.8  Pinheiros River in São Paulo: “Berrini” stretch with meanders, straightening, and aspects of urban occupation. (Source: https://inovaberrini.com.br/2020/11/rio-­pinheiros-cortava-­a-berrini/)

For São Paulo, the average rainfall potential to cause flooding was set at 60 mm in 72 h as the critical threshold. In the study conducted by Amaral (2020), it was found that “in the average of all recorded events, rainfall of about 48 mm causes flooding in the Córrego Ipiranga”; however, different thresholds were established along the basin. Still on the aspect of impermeabilization, Simas (2017), when analyzing the Aricanduva River/SP watershed, concludes that the areas in the highest infiltration-­ prone class were reduced by more than 99%, while the ones with runoff-prone areas increased by more than 18,000%, meaning that a considerable part of the water that causes chaos in certain risk spaces comes from other places and arrives through surface runoff, due to deforestation and high soil impermeabilization. Several studies highlight the occurrence of floods, especially in the impermeable areas of the floodplains, whose impacts are potentiated by urbanization, the intensification of construction, and the lower potential of artificial drainage systems. Simas et  al. (2017) state, in broader terms, that floods in the São Paulo metropolis are examples of events that disrupt the daily flows of the urban space and that highlight the historical problems of the city’s urbanization model. Still regarding urban land use, Jacintho et al. (2009) analyzed the waterproofing estimate for the city of São Paulo, combining demographic and remote sensing data. Despite the limitations of their methodology, the study indicated greater sealing in the central and eastern districts, following the watersheds of the Tietê River and its tributaries on the left bank, such as the Tamanduateí and Aricanduva.

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The problem of flooding in São Paulo is an old one, as previously stated, and has increased in different time and space scales. The main reasons for this serious problem are related to slow and persistent or rapid rains; to relief characteristics (flat and with low declivity) associated with the historical occupation of flood plains; to intense soil sealing, deforestation, real estate speculation, the presence of palliative measures, such as containment reservoirs (piscinões), and other inefficient engineering works; and to the weaknesses in environmental legislation and its enforcement, the absence of effective public policies, and the poverty-misery in which lives much of the population. When analyzing the environmental legislation and management for the reduction of flood-related risks in the city of São Paulo/SP, Amaral and Ross (2020 p. 501) state that “over time, the legislation surrounding the phenomenon of flooding presents a paradigm shift, where the focus, initially turned to the environmental protection of permanent preservation areas, shifts to the management of disaster risks.” Given the complexity of the problem, it is imperative that there be interdisciplinary studies that associate all these factors. On this issue, Simas et al. (2021), when performing a meta-analysis on urban flooding, noticed gaps regarding the development of interdisciplinary research aimed at understanding the occurrences of floods in urbanized areas in general and, particularly, in the humid tropical environment. Also according to these authors, one of the reasons for these gaps is that the causal factors identified tend to leave out the management of the physical environment, historical processes, and socioeconomic agents, focusing only on the production of disciplinary knowledge. Of the many solutions suggested for the control of urban flooding, the urban requalification for the city of São Paulo stands out, including urgent actions related to the occupation and use of the soil in areas at risk of flooding in the city. Within a huge set of public policies directly engaging the population and public and private institutions, the Climate Action Plan—PanClima SP (2020–2050)—deserves to be highlighted: developed by the city hall of São Paulo, it has over 43 actions designed to reduce greenhouse gas emissions by 2030 and zero emissions by 2050. The plan was approved by the Cities Climate Leadership Group (C40) which brings together 95 large cities that are leading the fight against climate change, with science-­ backed goals. Regarding the impacts and trends of climate risk, PanClima SP indicated a rise in the number of flood victims due to increased intense rainfall, in addition to higher death tolls from heat waves and droughts. The study sees these phenomena as one of the direct results of the urbanization process, and, even though it points to a regularity in the distribution of floods among the main rivers, it must be emphasized that the vulnerabilities will continue to reveal different scenarios and situations, given the expressive social inequalities. This context brings us back to Beck’s (2016) considerations, with which we agree and use to conclude this text: Beyond these issues of global inequality and competition, and the extent to which they can be moderated by new forms of transnational urban solidarity, it can also be said that climate-­ induced risks have their own “strategic” prerogatives. This is seen whenever a new storm or flood hits the world’s urban centers, making the risks of climate change tangible and urgent.

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These tangible urban realities may carry more weight than the abstract norms and future-­ oriented “duties” generated by global climate policy. When these realities hit the cities, they hit them hard, as witnessed by more and more of them. In addition to reducing carbon emissions, adaptation and urban resilience are becoming priorities on urban agendas around the world. Again, framing adaptation as a matter of urban rights and justice is central to realizing its transformative potential. Acknowledgments  I would like to thank Pedro Breda Fontão and Jailton Costa, who assisted in the elaboration of this text by collecting data and other valuable information.

References Almazroui, M., et al. (2021). Assessment of CMIP6 performance and projected temperature and precipitation changes over South America. Earth Systems and Environment, 5(2), 155–183. https://doi.org/10.1007/s41748-­021-­00233-­6 Amaral, R. (2020). Análise Integrada do Ambiente Urbano e as Inundações Recorrentes: caso da Bacia do Córrego Ipiranga (São Paulo/SP). Tese (Doutorado em Geografia Física) – Faculdade de Filosofia, Letras e Ciências Humanas, Universidade de São Paulo, . Amaral, R., & Ross, J. L. S. (2020). Legislation and management for risks reduction related to floods in São Paulo/SP, Brazil. Sociedade & Natureza [online], 32(1), 501–514. BECK, Ulrick. (2016). A metamorfose do mundo. Lisboa, Edições 70. Bell, J. E., et al. (2018). Changes in extreme events and the potential impacts on human health. Journal of the Air & Waste Management Association, 68(4), 265–287. https://doi.org/10.108 0/10962247.2017.1401017 Debortoli, N. S., Sung, C. L., & Hirota, M. (2020). Assessing farmers’ vulnerability to extreme weather events in the Araranguá river watershed - southern Brazil. Vulnerability Studies in the Americas: Extrem Wea Clim Chang, 125. EM-DAT. (2022). The International Disaster Database. Base de Dados sobre Inundações no Brasil (1992–2022). Goudard, G., & Mendonça, F. (2022). Riscos Hidrometeorológicos Híbridos na Bacia do Alto Iguaçu - Paraná (Brasil). Confins [online], 54(1). Hammond, M.  J., et  al. (2015). Urban flood impact assessment: A state-of-the-art review. Urban Water Journal, 12(1), 14–29. https://www.tandfonline.com/doi/abs/10.108 0/1573062X.2013.857421 IPCC  – Intergovernmental Panel on Climate Change. (2014). Fifth Assessment Report  - AR5. Retrieved from https://www.ipcc.ch/assessment-­report/ar5/ IPCC. Summary for Policymakers. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson Delmotte, V., P. Zhai, A. Pirani, S. L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J. B. R. Matthews, T. K. Maycock, T. Waterfield, O. Yelekçi, R. Yu and B. Zhou (eds.)]. Cambridge University Press. In Press, 2021. https://www.ipcc.ch/report/ar6/wg1/downloads/ report/IPCC_AR6_WGI_SPM.pdf IPCC  – Intergovernmental Panel on Climate Change. (2022). Sixth Assessment Report  – AR6. Retrieved from https://www.ipcc.ch/assessment-­report/ar6/ Jacintho, L. R. C., Almeida, T. I. R., & Gouveia, S. S. (2009). Estimativa da impermeabilização do solo urbano da cidade de São Paulo combinando dados demográficos e de sensoriamento remoto. Anais XIV Simpósio Brasileiro de Sensoriamento Remoto, Natal, Brasil, 25–30 INPE, 707–714.

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Luz, R. A., & Rodrigues, C. (2020). O processo histórico de ocupação e de ocorrência de enchentes na planície fluvial do rio Pinheiros de 1930 até os dias atuais. Geousp – Espaço e Tempo [online], 24(2), 340–360. Marengo, J. A., Lincoln, M. A., Ambrizzi, T., Young, A., Barreto, N. J. C., & Ramos, A. M. (2020). Trends in extreme rainfall and hydrogeometeorological disasters in the Metropolitan Area of São Paulo: A review. Annals of the New  York Academy of Sciences [online], 1472(Special Issue: The Year in Climate Science Research), 5–20. Mendonça, F. (2011). Riscos, vulnerabilidades e resiliência socioambientais urbanas: inovações na análise geográfica. Revista da ANPEGE, 7(1), 111–118. Mendonça, F. (2020). Riscos híbridos. Oficina de Textos. Mendonça, F., & Danni-Oliveira, I. M. (2007). Climatologia – Noções básicas e climas do Brasil. Oficina de Textos. O'donnell, E.  C., & Thorne, C.  R. (2020). Drivers of future urban flood risk. Philosophical Transactions of the Royal Society A, 378(2168), 20190216. https://doi.org/10.1098/ rsta.2019.0216 PanClima SP. (2021). Plano de Ação Climática do Município de São Paulo 2020–2050. Prefeitura do Município de São Paulo, 2021. Raymond, C., et  al. (2020). Understanding and managing connected extreme events. Nature Climate Change, 10(7), 611–621. https://doi.org/10.1038/s41558-­020-­0790-­4 Rodrigues, C. (2015). Atributos ambientais no ordenamento territorial urbano: o exemplo das planícies fluviais na metrópole de São Paulo. GEOUSP  – Espaço e Tempo [online], 19(2), 325–348. Santos, M. (1993). A urbanização brasileira. São Paulo, Editora Hucitec. Santos, F. A. (2006). Domando as Águas: salubridade e ocupação do espaço na cidade de São Paulo, 1875–1930. Tese de Doutoramento, IE, Unicamp. Santos, F.  A. A. (2011). Invasão das Águas ou as Águas Invadidas? A Construção Social e Econômica das Enchentes na Cidade de São Paulo (1875–1963). Anais do XXVI Simpósio Nacional de História – ANPUH, . Simas, I. T. H. (2017). Análise retrospectiva de episódios de inundações na Bacia Hidrográfica do Rio Aricanduva – São Paulo. Dissertação (Mestrado em Geografia Física), Faculdade de Filosofia, Letras e Ciências Humanas, Universidade de São Paulo, . Simas, I. T. H., Rodrigues, C., & Sant’anna Neto, J. L. (2017). Análise retrospectiva de inundação na bacia do Rio Aricanduva, São Paulo. Boletim Paulista de Geografia [online], 97, 1–19. Simas, I. T. H., Rodrigues, C., Cazaroto, B. S. R., & Rodrigues, B. S. (2021). Metanálise de pesquisas sobre inundações urbanas: identificação de fatores causais e métodos empregados em estudos recentes. Revista do Departamento de Geografia [online], 41(1). Swiss Re Institute. (2022). Natural catastrophes in 2021: the floodgates are open. Retrieved from https://www.swissre.com/institute/research/sigma-­research/sigma-­2022-­01.html. Trenberth, K. E., Fasullo, J. T., & Shepherd, T. G. (2015). Attribution of climate extreme events. Nature Climate Change, 5(8), 725–730. https://doi.org/10.1038/nclimate2657 Zilli, M. T., Carvalho, L. M. V., Liebmann, B., & Dias, M. A. S. (2017). Uma análise abrangente das tendências de precipitação extrema na costa sudeste do Brasil. International Journal of Climatology [online], 37(5).

Chapter 2

Intra-urban Spatial Configuration and Hydrological Responses Spatially Distributed in Basins: Contributions to a Sustainable Development Juliana Wilse Landolfi Teixeira de Carvalho and Irani dos Santos

Abstract  Urban floods result from the synergistic effect of elements of both natural and anthropic origin. Among them, the impacts of increasing impervious areas in surface runoff and peak flow during rainfall events are discussed in the scientific literature. In this chapter, we discuss, from the urban hydrology perspective, the hydrological responses that result from the urban spatial configuration and its influence on flood susceptibility. We approach the theoretical principles of urban space compartmentalization into Hydrological Similarity Areas (HSA) and its application in urban planning. We display an example of HSA delimitation and simulate their urban water balance in Belém catchment, Southern Brazil. The results reveal how the heterogeneity of urban spatial configuration influences the behavior of water balance parameters, where the increase in impervious areas increases runoff and decreases infiltration and evapotranspiration rates. In this chapter, we also discuss how nature-based solutions (SbN) applied in strategic areas (HSA) can reduce flood susceptibility and support sustainable urban development.

2.1 Floods and Urban Water Dynamics According to the United Nations’ World Water Development Report, published in 2021, flooding is one of the most frequent and representative water-related disasters on a global scale. Between 2009 and 2019, floods affected approximately 103 million people worldwide and caused $76.8 billion in economic losses. The UN-Habitat (2016) estimates that 1.2 billion people live in flood-prone areas, with the majority of those living in urban spaces; this number is expected to increase to 1.6 billion by 2050. In Brazil, the urban population has more than doubled in the last 30 years, reaching 84% of the total population in 2010 (IBGE, 2010). This increase, however, J. W. L. T. de Carvalho (*) · I. dos Santos Federal University of Paraná, Curitiba, Paraná, Brazil © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 F. Mendonça et al. (eds.), Urban Flooding in Brazil, https://doi.org/10.1007/978-3-031-20898-0_2

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mainly occurred in a disorganized way and out of sync with infrastructure planning and investments, thus pressuring natural resources and increasing disaster risks. Urban flooding is an increasingly common reality in Brazilian cities, especially those located in headwater catchments. In addition to heavy rainfall, flooding is commonplace in more than half of the Brazilian municipalities and almost all the country’s capital cities (IBGE, 2008). Both its occurrence and increased intensity and frequency result from the synergistic effect of elements and practices that currently shape Brazilian urban environments, as well as environmental factors such as climate change, which intensify the incidence of extreme events (PBMC, 2014; IPCC, 2018). In order to clarify the relationship between these factors and the origin of urban flooding, it is necessary to comprehend the complexity of urban water dynamics and their related impacts. Understanding the urban water cycle requires recognizing that cities are built on water basins. Hence, the spatial configuration of the urban environment dynamically changes the water cycle and the rates of the water balance components. In the water cycle—traditionally defined as the phenomenon in which water moves between the earth’s surface and the atmosphere—precipitation is the system input, and streamflow and evapotranspiration are the outputs. In non-urbanized basins, the water can take different pathways, such as interception, infiltration, percolation, groundwater recharge, aquifer supply, and surface runoff. The insertion of anthropic elements in drainage basins increases the complexity of water systems due to the increase in this diversity and the changes in the water balance. In urban environments, water from the public water supply is also an input, whereas wastewater constitutes a new output. The built rainwater drainage system, in turn, adds to the natural drainage network, composing a new runoff dynamic. Figure 2.1 shows how the three built systems (public water supply, sewerage, and

Fig. 2.1  Urban water cycle

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rainwater drainage system) interact with each other and the natural drainage system, diversifying the pathways on urban water dynamics. The understanding of such diversity reveals a range of water resource management particularities in urban environments, given the following main changes in the urban water cycle: • Wastewater into the Drainage System: Despite the regulations proposed by the NBR 9649 norm (ABNT, 1986) in Brazil defining separate sanitary sewers as the default system, which is characterized by the total separation between wastewater and rainwater drainage, there is a large volume of effluents illegally discharged into the rainwater network or directly into rivers. • Rainwater into the Wastewater System: Just as there are many sewer connections in the drainage network, the opposite situation (illegal rainwater drainage connections in the wastewater network) is also recurrent. It can overload wastewater treatment stations (WWTPs) during rainfall, leading them to open their floodgates to discharge untreated effluents directly into the rivers. • Water Supply System Leakage: In Brazil, the average leakage in the public water supply is 39.2% (MDR, 2020). Among the country’s states, these percentages range from 29.2% (Goiás, central-western Brazil) to 73.6% (Amapá, northern Brazil) (MDR, 2020). The volume lost through leaking pipes in urban areas flows to the groundwater level, increasing the urban rivers´ baseflow. • Streamflow Surpassing Precipitation: Due to the increased volume lost in the public water supply and the wastewater presence in drainage networks, the streamflow volume surpasses the precipitation in many urban headwater catchments. • Diffuse Pollution: In urban spaces, a significant portion of water pollution comes from diffuse sources and is carried through the built drainage system to water bodies. It is estimated that, during rainfall events, the first 25 mm of surface runoff carries most of the pollutant load from the urban environment (Tucci, 2008). The quality of the water carried by the network depends on the type of land use in the basin, urban cleanliness, as well as precipitation intensity and temporal and spatial distribution. The main effects of this type of water pollution are the increase in heavy metals and solid waste concentration; the increase in the potential of hydrogen (pH) and water temperature; the decrease in oxygen saturation (SO2); and biodiversity loss (Tucci, 2005). Although not all of these changes directly contribute to the urban flooding magnitude, they are essential for understanding the distribution and volume transfer between systems and the demands on water resources management in urban environments. Examples of this indirect relationship are the presence of wastewater in the drainage network and diffuse pollution, which influence the spread of waterborne diseases among flood-affected populations. The accurate determination of water balance components is necessary to understand the urban flooding dynamics and subsidize its management. Studies by Cleugh et  al. (2005), Sharma et  al. (2008), Mitchell et  al. (2008), Lee et  al. (2010), and Mejía et  al. (2014) show through hydrological modeling that the increase in

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impervious areas in urban environments due to the presence of buildings, streets, and sidewalks results in significantly increased surface runoff and decreased water infiltration and evapotranspiration rates. The increased runoff volume reduces the water residence time in the catchments, increasing the peak flow rates and, consequently, the flood susceptibility during rainfall events. Although undertaken as part of the solution to the problem, channelization projects in rivers and brooks can also contribute to increasing peak flows and decreasing water residence time. According to Assumpção and Marçal (2012), Cunha (2012), and Sartório (2018), employing traditional river engineering works can render environments more susceptible to flooding, both downstream and at the intervention site, in addition to causing changes in the sedimentological, water, hydraulic, and biotic dynamics of rivers. Channelization includes river channel widening, deepening, and straightening, construction of artificial channels and levees, and works aiming at protecting riverbanks and dredging riverbeds. Overall, straightening and shortening the river course increase the flow speed, also contributing to higher peak flows. On the one hand, if soil sealing results in increased surface runoff, on the other, it reduces water infiltration. Such decrease in infiltration can substantially reduce groundwater recharge and, depending on the region, also compromise public water supply. This condition makes the paradoxical coexistence of scarcity and flood risk in the same space-time dimension a constant in large Brazilian cities. Reports of severe flooding during droughts and water crises in Brazilian capital cities are not uncommon, such as the cases in São Paulo (state of São Paulo, southeastern Brazil) in 2013 and 2014 and Curitiba (state of Paraná, southern Brazil) in 2020. The decrease in evapotranspiration rates, in turn, results from the decrease in the water volume intercepted by the vegetation or stored in the soil due to the reduction of pervious and vegetated areas. These changes can alter the urban microclimate, leading to heat islands and thermal inversion. Therefore, removing natural cover reduces the potential of ecosystem services provided by the vegetation, such as temperature and humidity regulation, carbon sequestration, and pollutant absorption. In this sense, changes in the microclimate can directly influence human health and well-being. Urbanization is one of the most transformative trends of the twenty-first century. It has major implications regarding its impacts on water resources due to the denaturalization of the processes related to the water dynamics of drainage basins (Carvalho et al., 2020). In addition, the lack of a perspective that integrates river and basin, combined with the lack of urban planning, hinders the development of resilient cities, especially given the climate change challenges. Along with the estimated urban growth and increasing impervious areas, climate change is challenging regarding potential impacts on the urban environment (UNESCO, 2020). Changes in the climate dynamics may lead to temperature and rainfall variations and, especially, to increases in both the frequency and intensity of extreme events, thus enhancing drought and flood risks (Asadieh & Krakauer, 2017; IPCC, 2018). According to UNESCO (2021), floods associated with extreme events have increased by approximately 50% in the last decade, and they are expected to

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become more intense in the coming decades. In the case of southern Brazil, it is estimated that the annual precipitation will increase as much as 30% by 2100; the wet days will decrease; and the extreme events will become more intense (PBMC, 2014). In view of the complexity of urban built spaces, we emphasize that the discussion on the range of elements associated with the urban flooding dynamics in headwater basins is virtually never-ending. Other elements, such as the distribution of informal settlements, drainage network design, and structural flooding, among others, may also be considered. In this study, however, we will focus on the observed water balance responses resulting from urban spatial configuration, soil sealing, and the denaturalization of hydrological processes from the perspective of urban hydrology. Since cities are built in basins, it is necessary to recognize that urban environments are spatially diverse and do not respond to water balance equally. Therefore, it is imperative to pay attention to the heterogeneity of intra-urban spaces in order to identify them, as well as to understand how this knowledge can foster planning, risk management, and the development of resilient and sustainable cities.

2.2 The Heterogeneity of Intra-urban Spaces Understanding urbanized areas as homogeneous spaces and identifying their standard behavior by various geographic analysis fields are widespread practices in the literature. Furthermore, they are influenced by the analysis scale and the research objectives. In urban hydrology, however, studying intra-urban spaces’ heterogeneity may be essential to understanding urban water dynamics and supporting territory planning and management. Given this heterogeneity, different configurations are expected to generate different hydrological responses. Despite the over-fragmentation of surface characteristics, it is possible to define different spatial configuration patterns, compartmentalizing the urban space into Hydrologic Similarity Areas (HSA). Classifying the urban space into HSA aims to identify areas presenting the same spatial configuration patterns and, therefore, similar water dynamics. These patterns indicate the highly dependent relationship between the percentage of impervious surfaces and the denaturalization of hydrological processes (Carvalho et al., 2020), which are reflected in the water balance (Mejía et al., 2014). An example of urban spatial configuration is that the downtown areas usually present a higher building concentration, high population density, less vegetation cover, and a higher percentage of soil sealing. Compared to downtown, residential neighborhoods may have higher vegetation cover due to the increased presence of gardens and parks and lower population density. Peripheral residential neighborhoods, however, tend to present higher rooftop and population density and little urban forestry. Different patterns can be found in areas intended for service, industry, and single and multi-family dwellings, among others.

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We highlight that the diversity of the intra-urban spaces can result from spontaneous urbanization or planning actions and often from both these processes together. In Brazilian cities, the most common urbanization process is spontaneous, which occurred mainly in the 1970s and 1980s. These decades were characterized by an intense rural exodus that caused the rapid growth of urban centers. Some cities that have been planned since the beginning, such as Goiânia (state of Goiás), Brasília (Federal District, central-western Brazil), and Palmas (state of Tocantins, northern Brazil), or that have undergone urban restructuring processes, such as Curitiba (state of Paraná, southern Brazil), have a history of zoning laws regulating land use and land cover. Nevertheless, even planned cities have characteristics resulting from both processes. The particularities of the historical processes of each city’s expansion provide a plethora of elements for analyzing the diversity of intra-urban spaces. Therefore, regardless of the city’s historical process, the urban environment has a heterogeneous spatial configuration, another factor that allows its compartmentalization into HSA.

2.2.1 Urban Configuration and Hydrologic Similarity Areas in the Belém Catchment, Curitiba, State of Paraná An example of compartmentalization of the urban space into HSA for later water balance modeling was performed in the Belém catchment. Located in Curitiba, the capital city of Paraná State, the catchment has approximately 87.5 km2. It represents 20% of the city’s territory, and reaches 47 neighborhoods, showing very diverse spatial configuration patterns. Furthermore, it encompasses several parks, housing, institutional, and service areas, as well as the city’s downtown. Flood episodes are registered annually, especially in the downtown and downstream areas close to the main river and its tributaries. According to Goudard and Mendonça (2020), high-­ intensity short-duration rainfall episodes are the primary flood triggers in Curitiba, combined with convective rainfall events in the warm months and the advance of cold fronts throughout the year. As it comprises highly urbanized areas, a significant portion of the catchment’s rivers were channelized, and several segments straightened. Historically, many interventions were conducted in these rivers in an attempt to solve flood-related problems. Due to the combination of climatic characteristics, low natural soil permeability (Guabirotuba geological formation) (Bigarella & Salamuni, 1962), increased percentage of impervious areas, and the presence of traditional river engineering works, Curitiba has suffered more than 200 flooding episodes in the last 30 years (Goudard, 2019). Among the most significant and recent events regarding impacts, the February 21, 2019 episode (Fig. 2.2) stands out, with precipitation of 119.6 mm/24 h. Many streets, houses, institutions, and commercial establishments were affected. Paraná’s Civil Defense registered floods in 18 neighborhoods, including the city’s downtown.

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Fig. 2.2  February 19, 2019, flood registered in the Boqueirão neighborhood, Curitiba/state of Paraná

Despite not having been planned since its creation, Curitiba underwent an urban restructuring between the 1970s and 1990s. Currently, the law that provides zoning and land use in the city determines some spatial pattern characteristics related to this planning. Other characteristics, however, result from past or ongoing processes of spontaneous urbanization, especially in peripheral neighborhoods. In order to evaluate the urban spatial configuration of the Belém catchment and define the HSA, we considered variables related to zoning and spontaneous urbanization. The zoning law divides Curitiba’s territory, establishing criteria for land use and land cover in each zone, such as the type of activity allowed, the maximum number of floors per building, and the occupancy rate per lot. The building pattern in each zone can directly influence the water dynamics of both current and future urban environments, such as imported water demand, wastewater production, rate of water infiltration, evapotranspiration, and surface runoff. Figure 2.3 shows Curitiba’s zoning within the Belém catchment. In total, the study area has 28 zones. The zoning law variables used to define the HSA were as follows: occupancy rate per lot in multi-family dwellings or non-residential buildings (basement, ground floor, 1st and 2nd floors); the maximum number of floors allowed in multi-family dwellings; maximum number of floors allowed in non-residential buildings; and expected occupancy density. The occupancy rate per lot can directly influence the percentage of impervious areas in each zone, and the maximum number of floors allowed per building indicates urban densification. Occupancy density, in turn, directly influences the volume of imported water and effluents produced and may indicate verticalization or soil sealing. Figure 2.4 shows the variables used to define the HSA.

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Fig. 2.3  Curitiba zoning law within the Belém catchment

Fig. 2.4  Cluster analysis and delimitation of Hydrologic Similarity Areas in the Belém catchment

The percentage of impervious areas was obtained by mapping the land use. It was employed as a complementary variable in HSA delimitation since it also provides data on spontaneous urbanization in addition to representing the planning effectiveness. The mapping was performed based on remote sensing techniques using CBERS4A satellite images (fusion of red, green, blue, and multispectral

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bands) with a 2-m spatial resolution and Curitiba’s street vectors (IPPUC, 2013). A sequence of rules was created to perform an object-oriented classification to vectorize the following classes: roofs, streets, sidewalks, and vegetation. The HSA were defined based on a hierarchical cluster analysis of the used set of variables. The Ward method was used for clustering similar zones. Hierarchical cluster analyses aim to divide sample elements into groups so that, based on measured variables, the ones within the same group are similar. According to the dendrogram resulting from this analysis, which was cut to a Euclidean distance of three, the zones were clustered into eight HSA (Fig. 2.4). The delimited Hydrologic Similarity Areas present the following characteristics: • AHS I  – Zones close to downtown or areas connecting to it: occupancy rate >75%; number of floors in multi-family dwellings between 3 and 6; number of floors in non-residential buildings between 3 and 6; high occupancy density; impervious areas >80%. • AHS II – Downtown or density zones: occupancy rate >75%; number of floors in multi-family dwellings >8; number of floors in non-residential buildings: unrestricted; medium/high and high occupancy density; impervious areas >80%. • AHS III – Mixed-use or residential areas: occupancy rate, 50%; number of floors in multi-family dwellings between 4 and 6; number of floors in non-residential buildings between 2 and 4; medium occupancy density; impervious areas >70%. • AHS IV – Zones close to downtown or highly populated: occupancy rate, 50%; number of floors in multi-family dwellings, 6; number of floors in non-­residential buildings, 6; medium to high occupancy density; impervious areas >70%. • AHS V – Residential or service areas: occupancy rate, 50%; number of floors in multi-family dwellings between 2 and 6; number of floors in non-residential buildings, 2; medium/low and medium density; impervious areas >70%. • AHS VI – Single-family residential zone: occupancy rate, 50%; number of floors in multi-family dwellings, 0; number of floors in non-residential buildings, 2; low occupancy density; impervious areas