2013年-世界发展银行全球_Economic_and_Spatial_Study_of_the_Vulnerability_and_Adaptation_to_Climate_Change_of_Coastal_Areas_in_Senegal_123页_7mb

Summary of the Economic and Spatial Study of the Vulnerability and Adaptation to Climate Change of Coastal Areas in Senegal

Core Content

This study examines the vulnerability and adaptation strategies for coastal areas in Senegal, focusing on the impacts of climate change and natural risks. It is part of a broader effort to enhance the resilience of coastal zones and integrate climate considerations into development planning. The research was conducted in collaboration with the World Bank and supported by the governments of Norway and Finland, as well as the European Union. It provides a spatial and economic analysis of the risks and outlines potential adaptation measures for three pilot sites: Saint-Louis, Rufisque-Bargny, and Saly.

The study was initiated in 2011 and completed in 2012, with a detailed methodology and four key time horizons: 1990, 2010, 2030, and 2080. The findings highlight the increasing risks to coastal areas due to both natural processes and human activities, such as urbanization, sand extraction, and inadequate infrastructure.

Main Objectives and Approach

• Objective 1: Conduct a spatial and economic analysis of coastal vulnerability to climate change and natural risks.
• Objective 2: Evaluate the costs and benefits of various adaptation options in three pilot sites.
• Approach: A structured and progressive methodology was used, combining spatial analysis with economic modeling and cost-benefit analysis (CBA). The study also emphasized the need for a long-term strategic vision and decision support for coastal planning.

Key Findings

Natural Risks and Climate Change

• Coastal Segmentation: The Senegalese coastline is divided into segments based on land use and occupation, revealing areas of high vulnerability.
• Urban Vulnerabilities: Urban areas are particularly vulnerable due to unplanned growth, inadequate infrastructure, and land use changes.
• Climate Trends:
  • Mean annual temperature is expected to rise by 1.1–1.2°C by 2030 and 2.6–4°C by 2080.
  • Precipitation patterns show a North-South gradient, with a potential increase in rainfall by 2030 and decrease by 2080.
  • Sea level rise is projected to be 20 cm by 2030 and 80 cm by 2080, significantly increasing the risk of coastal erosion and marine submersion.
• Erosion and Submersion Risks:
  • By 2080, 75% of the shoreline is expected to be at high risk of erosion.
  • Two-thirds of the shoreline could face a high risk of marine submersion.
  • In Saint-Louis, 80% of the city could be submerged during a 100-year storm by 2080, affecting 150,000 inhabitants.
  • In Rufisque-Bargny, 300 buildings (2,250 people) could be at risk of disappearance due to erosion.
  • In Saly, 60% of the current beaches may vanish by 2080, threatening tourism and local communities.

Economic Analysis

• Cost-Benefit Analysis (CBA): The study evaluates the economic implications of natural risks and climate change, providing a net present cost (NPC) analysis for each site.
• Adaptation Costs:
  • Saint-Louis faces significant costs due to potential submersion and flooding.
  • Rufisque-Bargny requires costly strategic retreat measures to mitigate erosion.
  • Saly benefits from a mix of protection and recharging measures to preserve its coastal resources.
• Macroeconomic Impact: The study extrapolates the risks and costs to the entire Senegalese coastline, showing the potential for widespread economic and social impacts.

Proposed Intervention Programme

The study recommends a comprehensive intervention programme that includes:

• Investments and Technical Measures:
  • Construction of heavy-weight maritime structures (groins, T-shaped groins) and longitudinal beach-top structures.
  • Strategic retreat of urban areas to reduce exposure to natural risks.
  • Massive recharging of groundwater and artificial beach creation.
• Regulatory and Territorial Planning:
  • Implementation of territorial planning policies to manage land use and prevent further encroachment.
  • Integration of climate resilience into development plans.
• Institutional Aspects:
  • Strengthening institutional coordination between national and local stakeholders.
  • Enhancing data collection and mapping using GIS and other tools.
• Training and Awareness-Raising:
  • Civic education to reduce risk exposure.
  • Awareness-raising programs focused on self-protection.
  • Information dissemination on natural risks and climate change.

Limitations and Added Value

• Limitations:
  • Uncertainties in topographic data and climate forecasts.
  • Hazard evaluation is limited by the lack of detailed models for extreme weather events.
  • Economic analysis is constrained by the absence of long-term data and the complexity of integrating climate change into existing economic models.
• Added Value:
  • The study provides a flexible and updatable economic model for decision-making.
  • It highlights the need for coordinated and integrated coastal management.
  • It supports the national coastal erosion prevention program and the Coastal Law.

Recommendations for Replication

• Evaluation of Hazards:
  • Topographic knowledge is essential for accurate risk assessment.
  • Climate knowledge must be updated regularly using regional climate models.
  • Oceanographic and sedimentological data are critical for understanding coastal dynamics.
  • Hydrological and hydraulic analysis helps in assessing flood risks and managing water systems.
• Evaluation of Vulnerabilities:
  • Land use knowledge is necessary to identify vulnerable zones.
  • Territorial prospective should guide future land use planning.
  • Economic evaluation is key to prioritizing adaptation actions.
  • Fishing industry must be considered in vulnerability assessments due to its dependence on coastal ecosystems.

Conclusion

The study underscores the urgent need for climate-proofing coastal investments in Senegal. It provides a detailed spatial and economic analysis of the risks and outlines strategic adaptation measures for three key areas. The findings are crucial for informing Integrated Coastal Zone Management and for developing resilient infrastructure and policy frameworks that can withstand future climate challenges.