Integrating social vulnerability into high-resolution global flood risk mapping.

Area of Science:

• Environmental science
• Disaster risk reduction
• Geographic information systems (GIS)

Background:

• High-resolution global flood risk maps are vital for disaster planning, especially in data-limited, lower-income countries.
• Existing flood risk assessments often overlook spatial variations in social vulnerability, a critical factor influencing population outcomes.
• Understanding the interplay between flood exposure and social factors is essential for effective risk management.

Purpose of the Study:

• To develop a global vulnerability-adjusted risk index for flooding (VARI Flood) that integrates social vulnerability data.
• To create high-resolution (90-meter) flood risk maps accounting for population density and poverty.
• To identify global 'hotspots' of flood risk characterized by high population density and social vulnerability.

Main Methods:

• Integration of annual average exceedance probability estimates from a high-resolution fluvial flood model.
• Incorporation of gridded global population and poverty data.
• Development of a novel vulnerability-adjusted risk index (VARI Flood) at 90-meter resolution.

Main Results:

• A new global flood risk index (VARI Flood) has been created, incorporating social vulnerability at 90-meter resolution.
• The index identifies geographical 'hotspots' where high population density intersects with high social vulnerability.
• Results demonstrate significant spatial variation in flood risk when social vulnerability is considered.

Conclusions:

• The VARI Flood index offers a more comprehensive understanding of flood risk, emphasizing human well-being.
• This approach can complement traditional population and asset-centered risk assessments.
• The findings are particularly relevant for disaster risk planning and response in vulnerable regions worldwide.