Spatial and Temporal Analysis of Social Vulnerability to Environmental Hazards in the United States
Advisor: Dr. Susan L. Cutter
Social vulnerability characterizes how well communities are able to respond to, cope with, recover from and adapt to environmental hazards due to their socioeconomic composition. The Social Vulnerability Index (SoVI) quantifies social vulnerability at a county level for the United States for each of the following decades: 1960, 1970, 1980, 1990, and 2000. To fill a void in the current understanding of the spatial and temporal aspects of social vulnerability, this thesis focuses on analyzing the historical geography of social vulnerability (1960-2000), the spatial pattern of vulnerability, and the temporal trends. The analysis of the most socially vulnerable counties through time highlighted three main themes: development (urban); race/ethnicity (Native American); and race/socioeconomic status (lack of education, poverty, diversity). Conversely, the characteristics associated with low social vulnerability were socioeconomic status (wealth and education), homogeneous populations, and younger age structures. A global indicator of spatial autocorrelation, Moran’s I, was used to determine the overall spatial pattern of social vulnerability. All decades had significant positive spatial autocorrelation. However, the general linear trend of the Moran’s I through time suggested that the spatial pattern of social vulnerability was becoming more random and less concentrated in specific geographic regions over time. The Local Moran’s I was used to capture local variability and identify specific cluster areas of social vulnerability. Finally, a simple linear regression for each county was used to identify counties that experienced significant changes in social vulnerability.