2016年-世界发展银行全球_Lesotho_Water_Security_and_Climate_Change_Assessment_93页_9mb

Lesotho Water Security and Climate Change Assessment Summary

Core Content

This report provides a comprehensive analysis of Lesotho's water security in the context of climate change, focusing on the country's water management system, key vulnerabilities, and adaptation strategies. It is a product of the World Bank's Water Global Practice and is supported by the ACP-EU Natural Disaster Risk Reduction Program. The assessment uses a robust decision-making (RDM) framework and the Water Evaluation and Planning (WEAP) model to evaluate the impact of climate change on water resources and to identify resilient strategies for future water management.

Main Objectives

• Assess the impact of climate change on Lesotho's water security.
• Evaluate the effectiveness of current and potential adaptation strategies.
• Support the government in making informed decisions for sustainable development and climate resilience.

Key Institutions and Frameworks

• Lesotho Highlands Development Authority (LHDA): Key player in managing the Lesotho Highlands Water Project (LHWP).
• Ministry of Energy, Meteorology and Water Affairs: Coordinated the program.
• Ministry of Agriculture and Food Security (MAFS): Participated in the stakeholder process.
• WEAP Model: Used to simulate and evaluate the performance of water supply systems under various climate scenarios.
• Robust Decision-Making (RDM): Framework used to guide the analysis and interpret results across uncertain future conditions.

Climate Change Analysis

• Lesotho is projected to experience warmer temperatures (0.8°C to 2.9°C increase above historical average) from 2030 to 2050.
• Precipitation trends are uncertain, with some models predicting drier conditions and others wetter.
• 244 climate scenarios were analyzed, including 122 climate projections and two water demand scenarios.
• Figure ES.1 summarizes temperature and precipitation trends across these scenarios.

Water Security and Vulnerability

• Domestic and Industrial Water Demand: Current water supply is vulnerable to climate variability, with over half of the scenarios predicting unmet demand exceeding 20% for 2041-50.
• Rainfed Agriculture: Highly dependent on rainfall, making it susceptible to climate change impacts.
• Hydropower: A critical sector, but future climate projections suggest challenges in maintaining production.
• Lesotho Highlands Water Project (LHWP): A major infrastructure project that has provided significant economic benefits, but future climate change may threaten its reliability.
• Lesotho Highlands Botswana Water Transfer: An ongoing initiative to explore additional water transfer opportunities.

Adaptation Strategies

• Securing Water for Domestic and Industrial Growth: Enhancing water supply infrastructure to meet rising demand.
• Enhancing Agricultural Productivity through Irrigation: Developing irrigation schemes to reduce dependency on rainfall and increase food security.
• Sustaining Economic Options through the LHWP: Expanding the LHWP and its future phases to ensure continued economic benefits.
• Lowlands Bulk Water Supply Scheme (LLWSS): A recommended adaptation strategy to increase water security in lowland areas and reduce vulnerability to climate change.
• Capacity Building: Training resource managers in WEAP, R programming, and Tableau to support future climate analyses and decision-making.

Key Findings

• Lesotho's water resources are crucial for its socioeconomic development and economic growth.
• Climate change poses significant risks to water supply reliability, agricultural productivity, and hydropower generation.
• The Lesotho Highlands Water Project has been a major source of revenue, but future climate uncertainty may challenge its long-term sustainability.
• The LLWSS is a key adaptive measure that can improve water security and support economic development.
• A robust decision-making approach is essential for managing uncertainty and ensuring that water management strategies are resilient to a wide range of future conditions.

Recommendations

• Implement further phases of the Lowlands Bulk Water Supply Scheme (LLWSS) to enhance water security and reduce vulnerability to climate change.
• Expand irrigation infrastructure to support agricultural resilience and productivity.
• Strengthen capacity building for water resource modeling and climate analysis using tools like WEAP, R, and Tableau.
• Continue to integrate climate change considerations into water management planning and policy development.
• Ensure long-term sustainability of the LHWP and related water transfer initiatives to meet national and regional obligations.

Conclusion

This assessment underscores the importance of water for Lesotho's development and highlights the need for adaptive strategies to ensure resilience against climate change. The use of the WEAP model and RDM framework provides a structured approach to evaluating future risks and opportunities, supporting informed and sustainable water management decisions.