Social Vulnerability in United States Metropolitan Areas: Improvements in Hazard Vulnerability Assessment
Christopher T. Emrich
Advisor: Dr. Susan L. Cutter
Metropolitan areas of the United States are becoming more and more hazardous places to live, subject to a myriad of threats from natural hazards, technological failures, and willful terrorist acts. Along with this increasing potential for catastrophe is a similar rise in the vulnerability of the residents who live there. This vulnerability manifests itself as the potential for harm, but it also describes the inability of people and places to adequately respond to and rebound from hazard events. Theoretically based in the Vulnerability of Place Model, the spatial distribution of social vulnerability within two United States cities---Tampa-St. Petersburg, FL and Charleston, SC – was analyzed. The following research questions were posed:
- What socioeconomic factors influence social vulnerability within urban areas?
- What characteristics of the built environment cause differential vulnerability within the urban realm?
- What variations in lifelines and accessibility cause cities to exhibit higher or lower vulnerability to hazard events?
Variables representing three facets of social vulnerability-socio-economic, built environment, and accessibility—were standardized and placed in an un-weighted model. Experts in the natural hazards and disaster field were surveyed to determine the relative importance of variables in determining social vulnerability and these opinions were used as weights in a weighted model. The resulting models were compared to each other to formulate an understanding of how differential weighting of factors influenced each facet of social vulnerability.
Results indicate that although weighting does change overall vulnerability to some degree, the metropolitan pattern of vulnerability remains relatively constant across space, while local changes in all of the subcomponent facets as well as overall social vulnerability are more highly differentiated. These results provide an in depth look into those characteristics of a place or population that are most important in a spatial equation of social vulnerability. Such an understanding can aid policy makers, planners and individual families in planning for and reducing hazard impacts in the future through improvements in mitigation programs, zoning practices, and development policies.Dissertation