Sughosh Madhav, PhD, is Postdoctoral Fellow in the Department of Civil Engineering, Jamia Millia Islamia, New Delhi, India. Virendra Bahadur Singh, PhD, is Assistant Professor in the Department of Environmental Studies, Ram Lal Anand College, University of Delhi, New Delhi, India. Sushil Kumar Shukla, PhD, is Assistant Professor in the Department of Environmental Sciences, Central University of Jharkhand, Ranchi, Jharkhand, India. Ravi Shekhar, PhD, is Professor in the Centre for the Study of Regional Development (CSRD), School of Social Sciences, Jawaharlal Nehru University, New Delhi, India.

• List of Contributors xviiAbout the Editors xxiiiPreface xxv1 Desalination Technologies: Harnessing the Ocean for Freshwater Solutions 1Ambika Kumar, Deepika Dimri, Anshu Kumar, Abhijeet Ghosh, and Rajneesh Kumar1.1 Introduction 11.2 Desalination Technologies Overview 31.3 Conventional Desalination Technologies 51.3.1 Reverse Osmosis 51.3.1.1 Description and Working Principle 61.3.1.2 Technological Challenges and the Future of RO 71.3.2 MSF Distillation 81.3.2.1 Key Operational Parameters and Energy Requirements 81.3.3 Multi-effect Distillation 91.3.4 Electro Dialysis 101.3.4.1 Applications in Brackish Water Desalination 111.4 Emerging Desalination Technologies 111.4.1 Nanotechnology-based Membranes 111.4.2 Geothermal Desalination 111.4.3 Capacitive Deionization 121.4.4 Membrane Distillation 121.4.5 Advanced Reverse Osmosis 121.4.6 Forward Osmosis 131.4.7 Potential Advantages Over Traditional Methods 131.5 Energy Sources for Desalination 141.5.1 Conventional Energy Sources 141.5.2 RE Integration 141.6 Economic and Environmental Considerations 151.6.1 Cost Analysis of Desalination Technologies 151.6.2 Environmental Impact Assessments 161.7 Future Directions in Desalination Research 161.8 Conclusion 17Acknowledgements 18References 182 Restoration of Aquatic Ecosystems for Water Resource Management: Challenges and Sustainable Solutions 23S. Ganjingla, Imokokla Imsong, Ranika Roy, Susmita Reang, Ashutosh Tripathi-II, and Ashutosh Tripathi-I2.1 Introduction 232.2 Factors Affecting Water Resources 252.2.1 Rainfall (Indian Summer Monsoon) 252.2.2 Surface Water 252.2.3 Groundwater 262.2.4 Water Demand and Availability 262.3 Ecological Renewal in Water Resource Management: The Need 272.4 Importance of the Aquatic Ecosystem 282.5 Restoration of Aquatic Ecosystems 292.5.1 Principles of Restoration: Sustainable Solutions 312.5.1.1 Addressing the Root Cause of Degradation 322.5.1.2 Restoring Ecological Integrity 322.5.1.3 Nature-based Solutions: Climate Resilience and Adaptation 332.5.2 Restoring Native and Keystone Species 352.5.2.1 Restoring Hydrological Flow and Natural Regimes 362.5.2.2 Incorporating Technological Yet Cost-effective and Measurable Methods of Restoration Aligning with Adaptive Management 362.5.2.3 Integrating Stronger Legal and Financial Support for Sustainable Restoration 382.5.2.4 Community-led Aquatic Ecosystem Restoration: Integrating Indigenous Traditional Knowledge (ITKs) 392.6 Conclusion 40References 413 Groundwater Nitrate as a Key Concern of Water Scarcity in Arid Environment: A Special Focus on MENA Region 49Bedour Alsabti, Chidambaram Sabarathinam, Dhanu Radha Samayamanthula, Amjad Al-Rashidi, and Sara Al-Haddad3.1 Introduction 493.1.1 Study Area 513.1.2 Literature and Data Collection Strategy 533.2 Nitrate Levels in the MENA Region 533.3 Nitrate Natural (Geogenic) Sources in Groundwater 563.3.1 Other Geogenic Contaminants in Groundwater in the MENA Region 573.4 Anthropogenic Sources of Nitrate in Groundwater 583.4.1 Agriculture 583.4.2 Wastewater 583.5 Isotopic Evidence for Nitrate Contamination 603.6 Role of Ionic Ratios to Identify the Sources of Nitrate 603.7 Processes and Evolution Governing Nitrate in Groundwater 603.8 Mitigation and Strategies 613.9 Recommendation 62Acknowledgements 62References 634 Global Perspectives on the Impact of Climate Change on Water Scarcity, Including Regional Vulnerabilities, and Adaptation Strategies 73Deepika Dimri, Mayank Singh Bhakuni, Kamal Kant Joshi, Aparna Sarin, and Ambika Kumar4.1 Introduction 734.2 Regional Vulnerabilities of Water Scarcity as a Consequence of Climate Change Across the World 754.2.1 Water Scarcity in Africa 754.2.2 Water Scarcity in Asia 774.2.3 Water Scarcity in the Mediterranean and Middle East Regions 804.2.4 Water Scarcity in America 814.2.5 Water Scarcity in Australia 824.2.6 Water Scarcity Issue in the Transboundary River Basin 824.3 Planned Adaptation to Water Scarcity 834.4 Conclusion 84References 845 An Overview of Seawater Desalination Techniques, Challenges, and Opportunities 89Majid Peyravi and Zahra Goli Sangchi5.1 Introduction 895.2 Thermal Desalination 905.2.1 Multistage Flash 915.2.2 Multi-effect Distillation 925.2.3 Vapor Compression Distillation 935.3 Membrane-based Desalination 935.3.1 Electrodialysis 945.3.2 Reverse Osmosis 945.4 Hybrid Desalination Technologies 955.4.1 ED–RO Hybrid Process 965.4.1.1 Pretreatment of Entry Water 965.4.1.2 ED as Pretreatment 965.4.1.3 RO for Final Purification 975.4.1.4 Brine Management 975.4.1.5 Categories of ED–RO Hybrid Configurations 975.4.2 FO–MD Hybrid Systems 985.4.2.1 Preparation of FS and DS 985.4.2.2 FO: Primary Water Separation 995.4.2.3 Transfer of DS to the MD Process 995.4.2.4 Recovery and Regeneration of DS 995.4.2.5 Collection and Disposal of Residual Wastewater 995.4.3 RO–MD Hybrid Systems 1005.4.3.1 The Benefits and Drawbacks of RO–MD Systems 1005.4.4 RO–FO Hybrid Systems 1005.4.4.1 Marine Water Pretreatment Stage 1015.4.4.2 Process (FO): Transfer of Water to the Absorbent DS 1015.4.4.3 Separation of DS 1015.4.4.4 Water Passing the RO Membrane for Ultimate Desalination 1015.4.4.5 Wastewater Management and Energy Recovery 1015.4.4.6 Generation of Potable Water as the Final Product 1025.4.4.7 Configurations of RO–FO Hybrid Systems in Marine Desalination 1025.5 Solar-powered Desalination 1055.5.1 Direct Solar Desalination 1055.5.2 Indirect Solar Desalination 1055.5.2.1 Solar Photovoltaic 1055.5.2.2 Solar Thermal 1055.6 Conclusion 106References 1066 Examining the Causes of Water Scarcity in the World and the Impact of Water Economy 113Majid Peyravi and Samaneh Karimi6.1 Introduction 1136.2 Water Crisis and Its Main Causes 1136.3 The Importance of Studying Water Economics to Solve Crises 1176.4 Dimensions of the Water Crisis 1186.4.1 Reduction of Renewable Water Resources 1186.4.2 Increase in Water Demand 1196.4.3 Lack of Access to Clean Water 1206.5 Water Economics 1216.5.1 The Economic Value of Water 1216.5.2 Water Resource Management 1226.5.3 Problems in Water Resource Allocation 1246.6 Economic Effects of the Water Crisis 1256.6.1 Agriculture and Food Security 1256.6.2 Industry and Production 1286.6.3 Social and Health Impacts 1296.7 Solutions and Strategies 129References 1307 Innovative Approaches to Marine Water Desalination and Sustainable Utilization 133Nageswara Rao Lakkimsetty, Nourhan Hilal El Mohamad, Yahya Ali Hamadi, and Rahma Juma7.1 Introduction 1337.2 Importance of Marine Water Desalination 1347.3 Global Water Scarcity Concerns 1357.4 Environmental Impacts and Energy Challenges 1357.5 Need for Innovative and Sustainable Desalination Methods 1367.6 Conventional Desalination Techniques 1377.7 Recent Advancements in Desalination Technologies 1397.8 Environmental Impact and Mitigation Measures 1407.9 Economic Considerations and Cost-effectiveness Analysis 1417.10 Case Studies and Real-world Applications 1437.11 Future Directions and Research Opportunities 1437.12 Conclusion and Recommendations 145Acknowledgements 146References 1468 Advances in Water Resources Management by Protection and Restoration of Aquatic Ecosystems 149Punyavee Mohan, Ujjwalkant Singh, Kumar Ankush, Kartikey Bhatt, Nitya Rastogi, and Nidhi Verma8.1 Introduction 1498.2 Advancements in Water Management Strategies 1508.2.1 Monitoring 1508.2.2 Restoration of Aquatic Ecosystem 1518.2.2.1 Habitat Restoration 1518.2.2.2 Methods of Restoration 1548.2.3 Protection of Aquatic Ecosystems 1618.2.3.1 International Laws and Regulations 1628.3 Prospects and Recommendation 1648.3.1 Strengthening Global Cooperation and Knowledge-sharing 1648.3.2 Enhancing Public Awareness and Education 1648.3.3 Leveraging Emerging Technologies for Adaptive Management 1648.4 Conclusion 165References 1659 Groundwater Scarcity and Socioeconomic Impact Due to Coal Mining – Case Study on Shahdol District, Madhya Pradesh, India 175Ramesh Kumar, Piyali Sabui, Aaradhana Bora, and Pallavi Das9.1 Introduction 1759.2 Study Area 1779.3 Materials and Methods 1789.4 Results and Discussion 1799.4.1 Groundwater Scarcity 1799.4.2 Socioeconomic Impacts 1809.5 Conclusion 187Acknowledgements 187References 18810 Groundwater Scarcity: Assessment, Monitoring, and Management in India Using Geospatial Techniques 191Pankaj Kumar and Ravi Prakash Singh10.1 Introduction 19110.2 Status of Groundwater in India 19310.3 Regional Groundwater Status 19510.3.1 Groundwater Status in Northern India 19710.3.2 Groundwater Status in Central and Western India 19710.3.3 Groundwater Status in Southern India 19710.3.4 Groundwater Status in Eastern India 19710.3.5 Groundwater Status in Himalayan and Northeastern India 19810.4 Geospatial Technologies Application in Groundwater Monitoring 19810.4.1 RS for Groundwater Assessment 19810.4.1.1 GRACE Satellite Mission and Groundwater Storage Trends 19810.4.1.2 Optical and Microwave RS for Groundwater Monitoring 19910.4.2 GIS-based Groundwater Potential Mapping 19910.4.2.1 MCDA in Groundwater Studies 20010.4.3 Hydro-climatic Models and Machine Learning Applications 20010.4.3.1 ML and AI in Groundwater Studies 20110.5 Geospatial Techniques in Groundwater Recharge Management 20110.5.1 Geospatial Innovations for Real-time Groundwater Monitoring and Management 20110.6 Summary and Conclusions 202References 20311 Revival and Rejuvenation of Aquatic Ecosystems for Water Resource Management 207Priyanka Varma and Paulami Sahu11.1 Introduction 20711.2 Aquatic Ecosystem 20711.2.1 Freshwater Ecosystem 20811.2.1.1 Types of Freshwater Ecosystem 20811.2.1.2 Causes and Threats to Water Resources 20911.2.1.3 The Concepts of Revival and Rejuvenation 20911.2.1.4 The Aim and Purpose of Conducting the Study 21011.2.1.5 Treatment Processes 21011.3 Conclusion 223References 22412 Understanding the Role of Water Scarcity in Natural Disaster Vulnerability: An Overview 229Chitrangada Debsarma and Paulami Sahu12.1 Introduction 22912.2 Understanding Water Scarcity 23112.2.1 Water Scarcity and Climate Change 23212.3 Natural Disasters Linked to Water Scarcity 23312.3.1 Droughts 23312.3.2 Wildfires 23512.3.3 Floods 23612.4 Social and Economic Impacts of Natural Disasters 23812.5 Case Studies 23812.6 Strategies to Address Water Scarcity and Disaster Resilience 23912.6.1 Technological Innovations in Water Scarcity and Disaster Management 24112.7 Concluding Remarks 242References 24213 Role of Geogenic Contaminants in Water Scarcity and Remediation Approaches 249Ayushi Priya, Deepansha Raina, Gaurav, Mohit Marwah, Sunila Hooda, and Shalini Swami13.1 Introduction 24913.2 Geogenic Contaminants: Origin, Types, and Their Impacts 25013.2.1 Definition and Origin of Geogenic Contaminants 25013.2.2 Geogenic Contaminants: Types and Their Ecological and Health Impacts 25113.2.3 Effects of Contaminants on Flora and Fauna 25213.3 Bioremediation as a Sustainable Removal Strategy 25313.3.1 Fundamentals of Bioremediation and Its Significance in Water Management 25313.3.2 Strategies in Bioremediation for the Removal of Geogenic Contaminants 25413.3.2.1 Bioaugmentation 25513.3.2.2 Bio-stimulation 25513.3.2.3 Biosorption 25513.3.2.4 Bioaccumulation 25513.3.2.5 Bioleaching 25513.3.2.6 Biotransformation 25513.3.2.7 Bioprecipitation 25513.3.3 Role of Microbial Communities in Bioremediation 25613.3.4 Challenges in Bioremediation 25713.4 Case Study: Bioremediation as an Approach to Reduce Geogenic Contamination 25813.5 Strategies for Sustainable Water Management 25913.5.1 Significance of Advanced Detection and Bioremediation in Mitigating Water Scarcity 25913.5.2 Integration with Other Water Management Approaches for Generating Freshwater 26013.5.3 Guidelines and Frameworks to Address Geogenic Contamination 26113.6 Conclusion 261References 26214 Harnessing the Rain: A Path to Water Sustainability 269Pushpendra Singh, Pooja Yadav, and Shruti Dutta14.1 Introduction 26914.1.1 The Concept of RWH 27014.2 Historical Perspective 27114.2.1 Traditional RWH Practices Across Civilizations 27114.2.2 Stepwells in India 27114.2.3 Cisterns in the Mediterranean 27114.2.4 Other Notable RWH Practices 27214.3 Evolution of Modern RWH Techniques 27214.3.1 Early 20th-century Developments 27214.3.2 Lessons from Indigenous and Traditional Knowledge 27214.3.3 Technological Advancements in the Late 20th Century 27314.3.4 The 21st-century Innovations 27314.3.5 Global Policy and Advocacy 27314.4 Components of RWH Systems 27314.4.1 Catchment Area 27414.4.2 Conveyance System 27414.4.3 Filtration System 27414.4.4 Storage Facility 27514.4.5 Distribution System 27514.5 RWH Techniques 27514.5.1 Rooftop RWH 27514.5.2 Surface Runoff Harvesting 27614.5.3 Groundwater Recharge Systems 27614.5.4 Rain Gardens and Bioswales 27714.5.5 Storage Reservoirs and Ponds 27714.5.6 Permeable Pavements 27714.5.7 Check Dams and Contour Bunding 27714.6 Benefits of RWH 27814.6.1 Alleviating Water Scarcity 27814.6.2 Reducing Groundwater Depletion 27814.6.3 Mitigating Urban Flooding 27814.6.4 Cost Savings 27814.6.5 Environmental Benefits 27814.6.6 Enhanced Water Quality 27914.6.7 Supporting Agriculture 27914.6.8 Climate Resilience 27914.6.8.1 Regions with Increasing Rainfall 27914.6.8.2 Regions with Declining Rainfall 27914.6.8.3 Adaptability Across Extremes 28014.6.9 Community Empowerment 28014.6.10 Biodiversity and Ecosystem Preservation 28014.7 Challenges in Implementing RWH 28014.7.1 High Initial Costs 28114.7.2 Maintenance and Operational Challenges 28114.7.3 Water Quality Concerns 28114.7.4 Limited Awareness and Education 28114.7.5 Space Constraints in Urban Areas 28214.7.6 Dependence on Rainfall Patterns 28214.8 Global Success Stories of RWH 28214.8.1 Singapore: The NEWater Initiative 28214.8.2 Australia: The City of Toowoomba 28214.8.3 Germany: The Town of Emsdetten 28314.8.4 South Africa: The Cape Town Initiative 28314.8.5 United States: The City of Berkeley, California 28314.9 Indian Success Stories of RWH 28414.9.1 State-wide Implementation (Tamil Nadu) 28414.9.2 The Village of Alwar (Rajasthan) 28414.9.3 The City of Bangalore (Karnataka) 28514.9.4 Success of Traditional Methods (Kerala) 28514.9.5 RWH in Pune (Maharashtra) 28514.10 Conclusion and Future Directions 28514.10.1 Integration with Technology and Circular Water Use 28614.10.2 Policy, Public–Private Partnerships, and Community Models 28614.10.3 A Climate-resilient Future 286References 28615 Global Water Availability and Its Consumption in a Changing Climate: Management Strategies 291Madhupriya, Sushil Kumar, Gavendra Pandey, Rakesh Kumar, and Sudesh Yadav15.1 Introduction 29115.2 Global Water Availability and Consumption 29215.3 Interrelationship Between Water Scarcity and Climate Change 29415.3.1 Rising Temperature 29415.3.2 Changing Precipitation Pattern 29515.3.3 Inland Surface Water 29515.3.4 Groundwater Depletion 29615.3.5 Management Strategies for Water Scarcity in Changing Climatic Conditions 29615.3.6 Integrated Water Resources Management 29615.3.7 Desalination and Water Recycling 29815.3.8 Policies and Governance Initiatives 29915.4 Case Studies 30015.4.1 India: Water Scarcity and Management Strategies 30015.4.2 African Countries: The Challenge of Water Insecurity 30015.4.3 European Countries: Issue of Water Stress 30115.5 Conclusion 302References 30216 Rainwater Harvesting: Strategies for Combating Water Scarcity 311V.S. Yadav, R.V. Galkate, V.K. Chandola, V.K. Tripathi, Samikshya Panda, Chinmaya Panda, and Harshita Rani Ahirwar16.1 Introduction 31116.1.1 RWH Technologies 31516.1.2 Potential of RWH Technology 31716.1.3 Benefits, Limitations, and Challenges of RWH Technology 31816.1.4 Necessity of RWH in India in Recent Times 31916.2 Hypothetical Case Study on Rooftop Rainwater Harvesting in Bengaluru City 31916.2.1 Problem Statement 32016.2.2 Study Area 32016.2.3 Case Study Description 32116.2.3.1 Annual Water Requirement 32116.2.3.2 Rainwater Collection Potential 32216.2.3.3 Potential of RWH on an Annual Basis 32216.3 Summary and Conclusion 324References 32417 Restoration Strategies for Rivers and Wetlands Affected by Overextraction of Water 331Vamsi Krishna Kudapa17.1 Introduction 33117.2 Rivers and Wetlands Affected by Overextraction 33217.2.1 Hydrological Alterations 33317.2.1.1 Reduced Streamflow 33317.2.1.2 Drop in Groundwater Level 33417.2.1.3 Increasing Frequency of Drought 33517.2.1.4 Changes in Sediment Transport 33517.2.1.5 Decreased Water Quality: As Flows Decline, the Pollutant Concentrations Increase, Impacting Drinking Water Sources and Aquatic Habitats 33717.2.2 Ecological Consequences 33817.2.2.1 Plan to Reduce Damage to Wildlife Habitats by Reducing Water Overextraction 33817.2.2.2 Decreased Water Purification and Flood Control 33817.2.2.3 Alteration of Migration Patterns 33917.2.3 Socioeconomic Impacts 33917.2.3.1 Decrease in Fisheries and Agricultural Productivity 34017.2.3.2 More Water Conflicts in Related Disciplines 34117.2.3.3 Ecosystem Services Loss 34117.3 Restoration Strategies 34117.3.1 Hydrological Restoration 34217.3.1.1 Environmental Flow Release 34217.3.2 Ecological Engineering Strategies 34417.3.2.1 Wetland Restoration and Creation 34417.3.2.2 Riparian Buffer Zones 34417.3.2.3 Bioengineering Techniques 34517.3.3 Policy and Regulatory Actions 34517.3.3.1 Restoration Strategies for Water Resources from Overextraction 34517.3.3.2 Water Allocation Policies 34517.3.4 Integrated Water Resources Management 34717.3.4.1 Watershed Management Plans 34717.3.4.2 Stakeholder Engagement 34717.3.5 Legislative Frameworks 34817.4 Case Studies of Successful Restoration Efforts 34817.4.1 Case Study 1: The Murray–Darling Basin, Australia 34817.4.2 Case Study 2: Aral Sea Restoration, Kazakhstan 34817.4.3 Medina del Campo Groundwater Body, Spain 34917.5 Challenges and Future Perspectives 34917.6 Conclusion 350References 350Index 353