2017年-世界发展银行全球_Urban_Flood_Risk_Management_in_the_Pacific___Tracking_Progress_and_Setting_Priorities_54页_3mb

Summary of Urban Floods Community of Practice Knowledge Notes

Core Content

This document provides an overview of flood risk management (FRM) in Pacific Island Countries (PICs), highlighting the current state of practice, key challenges, and eight priorities for improvement. It emphasizes the need for a structured, integrated, and community-informed approach to managing flood risks in the region.

Main Points

Flood Impacts in PICs

• Loss of life: Severe floods have caused fatalities, with high-impact events often involving the destruction of houses. For example, a 1-in-100 flood in the Nadi catchment could result in 12–15 deaths.
• Health and education: Floods damage health facilities and schools, leading to waterborne diseases and educational disruptions. Children are particularly affected due to limited access to healthcare and increased involvement in household activities.
• Infrastructure damage: Roads, bridges, and water supply systems are frequently impacted. The 2014 Honiara flood destroyed a major bridge and closed the international airport for two days.
• Financial and economic costs: Floods impose significant economic burdens. In 2014, the Solomon Islands' Honiara flood cost 9.2% of GDP, with the mining and agriculture sectors bearing the largest losses.

Drivers of Flood Risk

• Climate variability and change: Floods are influenced by climate patterns such as El Niño and La Niña. Climate change is expected to increase flood frequency and intensity, particularly in low-lying areas.
• Environmental change: Deforestation and land use changes have contributed to increased runoff and flood severity. However, the effect of these changes on flood frequency is not universally significant.
• Floodplain development and urbanization: Rapid urban expansion on floodplains has increased exposure to flood risks. This is often driven by migration, economic opportunities, and limited land availability.

Key Information

Flood Risk Management Process

• The document outlines a benchmarking method to evaluate FRM practices in PICs, focusing on riverine flood hazards.
• It identifies 12 benchmarks to assess progress, including:
  1. Hydrological data collection/storage/reliability
  2. Hazard assessment (mapping)
  3. Exposure and vulnerability assessment (mapping)
  4. Risk assessment
  5. Flood risk management measures
  6. Flood modification measures
  7. Risk-informed land use planning and development controls
  8. Flash flood warning systems
  9. Emergency management planning and capability
  10. Community preparedness
  11. Flood risk management governance
  12. Flood risk management process rollout

Priorities for Improving FRM

1. Develop integrated and sustainable governance arrangements to coordinate flood risk management efforts.
2. Involve communities and stakeholders from the outset of the FRM process.
3. Apply a comprehensive flood risk management process that includes data collection, flood studies, and community studies.
4. Reframe the problem to consider flood risk as a combination of hazard, exposure, and vulnerability.
5. Broaden solutions to include both structural and nonstructural interventions.
6. Preserve and enhance river and floodplain capacity to convey floodwaters.
7. Reduce exposure and vulnerability through land use planning, resilient infrastructure, and voluntary relocation.
8. Enhance flood awareness and preparedness via early warning systems, emergency management plans, and community readiness.

Conclusion

The current flood risk management practices in PICs are fragmented and often lack a holistic, integrated approach. While some progress has been made, especially in early warning systems and local studies, significant gaps remain in governance, community engagement, and the application of a full FRM process. Improving flood resilience requires a combination of better data, inclusive planning, and sustainable interventions that address both the natural and human dimensions of flood risk.

Key Messages for Policy Makers

• A structured flood risk management process is essential to reduce impacts and enhance resilience.
• Community involvement and stakeholder engagement are critical for effective and sustainable solutions.
• There is a need for more comprehensive flood risk assessments and localized plans.
• Investment in hydrological monitoring, land use planning, and early warning systems should be prioritized.
• Strengthening governance and institutional capacity is necessary to support integrated flood risk management across the region.