This layer summarizes the social vulnerability index for populations within each county in the United States at scales 1:3m and below. It answers the question “Where are the areas of relatively higher risk within this county?” from the perspective of social vulnerability. For emergency response planning and hazard mitigation, populations can be assessed from a perspective of their vulnerability to various hazards (fire, flood, etc). Physical vulnerability refers to a population’s exposure to specific potential hazards, such as living in a designated flood plain. Social vulnerability refers to potential exposure due to population and housing characteristics: age, low income, disability, home value or other factors. For example, low-income seniors may not have access to a car to simply drive away from an ongoing hazard such as a flood. ESRI applied a model from Susan Cutter, University of South Carolina, Hazards Research Lab, Department of Geography (http://webra.cas.sc.edu/hvri/), to generate this data using current year demographics at the block group level. The map is designed to be displayed with semi-transparency of about 50% for overlay on other base-maps, which is reflected in the legend for the map.
