2011年-世界发展银行全球_North_Africa_Coastal_Cities_Address_Natural_Disasters_and_Climate_Change_28页_4mb

Summary of "Climate Change Adaptation and Natural Disasters Preparedness in the Coastal Cities of North Africa"

Core Content

This document presents a regional study conducted by the World Bank, focusing on the coastal cities of Alexandria, Casablanca, and Tunis, as well as the Bouregreg Valley in Morocco. The study aims to assess the risks posed by natural disasters and climate change and to propose adaptive strategies to enhance the resilience of these urban areas.

Main Cities and Areas Studied

• Alexandria, Egypt: Home to 4.1 million people, expected to grow to 6.8 million by 2030.
• Casablanca, Morocco: With a population of 3.3 million, projected to reach 5.1 million by 2030.
• Tunis, Tunisia: A key urban center, with a population of about 10 million in 2010, expected to grow to 15 million by 2030.
• Bouregreg Valley, Morocco: An area with potential for large-scale urban development, expected to accommodate up to 140,000 new residents by 2030.

Key Risks Identified

Natural Disasters

• Floods: Alexandria's low-lying areas and informal settlements are particularly vulnerable. Flooding risk is expected to rise from low in 2010 to medium in 2030.
• Coastal Erosion: Increasing sea levels and storm surges threaten the coastline. Coastal erosion is rated as medium in 2010 and high in 2030.
• Tsunamis and Marine Submersion: Coastal structures and low-lying areas are at risk. Marine submersion risk increases from medium to high.
• Seismicity and Ground Instability: Northern Egypt faces moderate seismic risks, which could increase with subsidence and urban growth.
• Tsunami/Marine Submersion: The historical Mohammed Ali sea wall in Alexandria could fail, increasing the risk of inundation in low-lying areas.

Climate Change Impacts

• Sea Level Rise: Expected to be 20 cm by 2030, which will compound existing risks.
• Extreme Weather Events: Increased frequency and intensity of heat waves, heavy rainfall, and storm surges.
• Water Scarcity: Due to population growth and industrial demand, water resources are becoming increasingly scarce, especially in Alexandria.

Trends and Projections

• The frequency of natural disasters in the region has increased from 3 per year in 1980 to over 15 in 2006.
• By 2030, the population of the three cities is expected to grow significantly, increasing the potential for losses from natural disasters and climate change.
• The study highlights that by 2030, about 20% of potential losses will be attributed to climate change, with this percentage likely to increase in future decades.

Adaptive Actions and Resilience Strategies

The study recommends a multi-pronged approach to enhance resilience and adapt to climate change:

Urban Planning

• Reorient future expansion away from high-risk areas.
• Incorporate climate projections into the 2030 Greater Alexandria Master Plan.
• Define city limits and establish land-use policies that account for future climate scenarios.

Institutional Preparedness

• Improve early warning systems for all types of disasters.
• Enhance communication and coordination among agencies involved in disaster response.
• Strengthen institutional capacity and emergency management systems.

Infrastructure Investments

• Upgrade coastal defenses and drainage systems.
• Implement routine maintenance of sewage systems to reduce flood-related risks.
• Invest in mobile water pumps and other adaptive infrastructure to manage drainage during extreme weather events.
• Consider "smart buoys" and satellite-linked systems for real-time monitoring of coastal hazards.

Economic Valuations

• The potential cumulative losses from natural disasters and climate change impacts in the three cities are estimated to exceed $1 billion for the 2010-2030 period.
• For Alexandria alone, the estimated cumulative damage is $1.72 billion in Net Present Value.
• Climate change impacts account for about 18% of the total potential losses in Alexandria.

Cost-Benefit Analysis

• The study provides "adaptation cost curves" to evaluate the cost-effectiveness of various remedial measures.
• "Soft" measures, such as urban planning and institutional reforms, are found to offer high returns on investment.
• Some infrastructure measures, although costly, may be justified for their intangible benefits, such as protecting heritage sites.

Conclusion

The study emphasizes the need for proactive adaptation and resilience planning in North African coastal cities. By integrating climate change projections into urban development and disaster preparedness strategies, these cities can reduce future risks and ensure sustainable growth. The findings provide a foundation for policy responses and investments, and highlight the importance of continuous updates to adaptation plans as new data and scenarios emerge.