2022-11-17-联合国教科文组织-2022年世界水发展报告_246页_14mb

United Nations World Water Development Report 2022: Groundwater - Making the Invisible Visible

Core Content

The United Nations World Water Development Report 2022 focuses on groundwater, emphasizing its critical role in global water security, socio-economic development, and climate resilience. It aims to raise awareness of this often-overlooked resource and promote sustainable management practices.

Groundwater accounts for 99% of all liquid freshwater on Earth and is essential for domestic, agricultural, and industrial uses. It provides half of the water used for domestic purposes globally, 25% of irrigation water, and is a vital source for rural populations who lack access to public or private water supply systems. Despite its importance, groundwater is often mismanaged, polluted, or overexploited, leading to long-term environmental and social consequences.

Main Points

Importance of Groundwater

• Critical for human and ecological well-being: Groundwater supports food and energy security, urban and rural settlements, and industrial activities.
• Climate resilience: Groundwater can buffer against climate change impacts by providing a stable water source during droughts.
• Sustainability challenges: Overuse, pollution, and lack of understanding threaten groundwater availability and quality.

Global Overview

• Freshwater distribution: Groundwater is a major component of the global water cycle, with significant variations in its availability and use across regions.
• Water stress and scarcity: Groundwater withdrawal and use patterns are closely linked to water stress and scarcity, especially in regions with limited surface water resources.
• Economic and social value: Groundwater is a low-cost, reliable source of water, crucial for poverty alleviation and job creation.

Key Sectors and Uses

• Agriculture: Groundwater is heavily used for irrigation, but its depletion and pollution are significant concerns.
• Human settlements: Both urban and rural communities rely on groundwater for drinking water, especially in areas with unreliable surface water supplies.
• Industry: Groundwater is used in various industrial processes, including energy production and mining, and its quality is often compromised by these activities.
• Ecosystems: Groundwater-dependent ecosystems (GDEs) are widespread and provide essential services, such as maintaining wetlands and supporting biodiversity.

Key Information

Challenges

• Pollution and overexploitation: Many aquifers are being polluted due to industrial and agricultural activities, and overuse is leading to depletion.
• Lack of data and governance: There is a need for better data collection, monitoring, and legal frameworks to ensure sustainable use.
• Climate change impacts: Changes in precipitation and sea level rise threaten groundwater systems, especially in coastal areas.

Opportunities

• Sustainable management: Integrated approaches, such as managed aquifer recharge (MAR), can help restore and protect groundwater.
• Innovation and collaboration: New technologies, legal reforms, and international cooperation are essential for effective groundwater governance.
• Policy development: Clear policies and management plans are needed to address the growing demand for water and ensure equitable access.

Chapters Overview

Chapter 1: Introduction

• Defines the purpose and scope of the report.
• Explains the unique properties of groundwater and its role in the water cycle.
• Highlights the need for better understanding and sustainable use.

Chapter 2: Legal and Institutional Aspects

• Discusses the legal frameworks governing groundwater.
• Covers institutional structures and the shift from volume-based to share-based water rights.

Chapter 3: Groundwater and Agriculture

• Examines the role of groundwater in irrigation and its impact on water quantity and quality.
• Notes the vulnerability of shallow groundwater systems to agricultural practices.

Chapter 4: Groundwater for Human Settlements

• Focuses on urban and rural water supply systems.
• Highlights the importance of groundwater in emergency situations and for marginalized communities.

Chapter 5: Groundwater and Industry

• Reviews the use of groundwater in industrial settings and its link to energy and mining.
• Emphasizes the need for accountability and pollution prevention.

Chapter 6: Groundwater and Ecosystems

• Explores the relationship between groundwater and ecosystems.
• Discusses the role of nature-based solutions in protecting GDEs.

Chapter 7: Groundwater and Climate Change

• Analyzes how climate change affects groundwater systems.
• Suggests adaptation and mitigation strategies, including geothermal energy use.

Chapter 8: Regional Perspectives

• Provides insights into groundwater challenges and management in different regions:
  • Sub-Saharan Africa: Focus on water scarcity and the role of groundwater in urban and rural settings.
  • Europe and North America: Advanced management practices and data collection.
  • Latin America and the Caribbean: Recharge rates and sustainable use.
  • Asia and the Pacific: High reliance on groundwater for irrigation and domestic use.
  • Arab Region: Groundwater depletion and transboundary cooperation.

Chapter 9: Building the Knowledge Base

• Discusses methods for characterizing, assessing, and monitoring groundwater.
• Highlights the importance of sharing knowledge and building capacity.

Chapter 10: Groundwater Policy and Planning

• Outlines the development of groundwater policies and management plans.
• Provides examples of successful policy implementation.

Chapter 11: Groundwater Management

• Details the technical and institutional aspects of managing groundwater.
• Includes strategies for controlling withdrawals and protecting water quality.

Chapter 12: Transboundary Aquifers

• Examines the challenges and benefits of managing shared aquifers.
• Discusses international cooperation mechanisms and legal frameworks.

Chapter 13: Financing for Sustainability

• Reviews current and required funding for groundwater management.
• Suggests innovative financing models, including blended finance and ecosystem service payments.

Chapter 14: Conclusions

• Summarizes the report's key findings and recommendations.
• Calls for a global shift in groundwater management and policy.

Key Figures and Boxes

• Figure 1: Estimated volumes of liquid freshwater on continents.
• Figure 3: Global groundwater withdrawal by sector and region.
• Figure 7: Distribution of fresh and brackish offshore groundwater.
• Figure 9: Groundwater-induced land subsidence hotspots.
• Box 1.1: Groundwater systems and their structure.
• Box 4.1: Successful urban groundwater management in Hamburg.
• Box 5.1: Groundwater quality monitoring benefits for AngloGold Ashanti.
• Box 6.1: Groundwater-dependent ecosystems in the Okavango Delta.
• Box 7.1: Managed aquifer recharge (MAR) strategies.
• Box 8.1: Cape Town water crisis and its implications.
• Box 13.1: Groundwater financing in Peru.
• Box 13.2: Blended finance and technology in Tanzania.
• Box 13.3: Payment for Ecosystem Services in Kumamoto.

Summary

The report underscores the urgent need for sustainable groundwater management, calling for a shift in perception and action. It highlights the interconnectedness of groundwater with human health, poverty reduction, and climate resilience, and emphasizes the importance of data, policy, and international cooperation in addressing these challenges. The 2022 edition is the first to focus specifically on groundwater, reflecting its growing significance in a world of increasing water demand and climate uncertainty.