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It’s not a plot of “safe” or “crimefree”, it’s a plot of several things mashed together (food, water, energy, transportation, others) that relate to the ability of that area to weather a crisis.

“This web map provides a simple summary of the social vulnerability of populations in each state or county in the United States in 2009. It answers the question “Where are the areas of relatively greater potential impact from disaster events within this state or county?” from the perspective of social vulnerability to hazards.

For emergency response planning and hazard mitigation, populations can be assessed by 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. There are various methods for calculating the potential or real geographic extents for various types of hazards.

Social vulnerability refers to sensitivity to this exposure due to population and housing characteristics: age, low income, disability, home value or other factors. The social vulnerability score presented in this web service is based upon a 2000 article from the Annals of the Association of American Geographers which sums the values of 8 variables as a surrogate for “social vulnerability”. For example, low-income seniors may not have access to a car to simply drive away from an ongoing hazard such as a flood. A map of the flood’s extent can be overlaid on the social vulnerability layer to allow planners and responders to better understand the demographics of the people affected by the hazard.

This map depicts social vulnerability at the block group level. At scales greater than 1:3 million, the social vulnerability score is calculated within each state, allowing regional views. At scales less than 1:3 million, the score is calculated within each county, more suitable for local views. A high score indicates an area is more vulnerable.

This web service provides a simplistic view of social vulnerability. There are more recent methods and metrics for determining and displaying social vulnerability, including the Social Vulnerability Index (SoVI) which capture the multi-dimensional nature of social vulnerability across space. See www.sovius.org for more information on SoVI.

The refereed journal article used to guide the creation of the model in ModelBuilder was: Cutter, S. L., J. T. Mitchell, and M. S. Scott, 2000. “Revealing the Vulnerability of People and Places: A Case Study of Georgetown County, South Carolina.” Annals of the Association of American Geographers 90(4): 713-737. Additionally, a white paper used to guide creation of the model in ModelBuilder was “Handbook for Conducting a GIS-Based Hazards Assessment at the County Level” by Susan L. Cutter, Jerry T. Mitchell, and Michael S. Scott.

Off-the-shelf software and data were used to generate this index. ModelBuilder in ArcGIS 9.3 was used to connect the data sources and run the calculations required by the model.”