Vulnerability Mapping and Social Inequality

Hazards geographers distinguish sharply between "hazard," the physical phenomenon such as a flood or heat wave, and "vulnerability," the social, economic, and demographic factors that determine how severely a given population is harmed by that hazard — two households facing an identical flood can experience wildly different outcomes depending on income, housing quality, insurance access, health status, and social networks. Geographer Susan Cutter and colleagues at the University of South Carolina's Hazards and Vulnerability Research Institute formalized this into the Social Vulnerability Index (SoVI) in a influential 2003 paper in Social Science Quarterly, combining census variables such as poverty, age, disability, race and ethnicity, and housing type into a composite county-level score used widely in U.S. hazard planning and later adapted internationally.