The Spatial Distribution of Biophysical Vulnerability from Natural Hazards in the United States
Mathew C. Schmidtlein
Advisor: Dr. Susan L. Cutter
Our understanding of the distribution of biophysical vulnerability in the United States has been limited in the past by a lack of data. The purpose for this thesis is to address this limitation by determining the spatial distribution of biophysical vulnerability from natural hazards within the United States using newly available data sources. Two main working hypotheses are considered. First, it is hypothesized that the distribution of biophysical vulnerability will likely have positive spatial association; that is, it will cluster in groups of high and low. Second, it is hypothesized that clusters of high biophysical vulnerability in the U.S. will likely occur in areas of high hazard diversity; these will likely be in either coastal areas or in the Great Plains. A cumulative hazard environment vulnerability index (CHEVI) is constructed from economic impact, human cost, occurrence interval and diversity variables derived from the Spatial Hazard Events and Losses Database for the United States (SHELDUS) at the county level for all 50 states and D.C. The CHEVI is used to assess the relative levels of biophysical vulnerability for each county. The local Moran’s I statistic, a measure of local spatial association, is used to identify significant clusters of high and low biophysical vulnerability. Biophysical vulnerability at the county level is found to cluster in the U.S., confirming the first hypothesis. The second working hypothesis is only partially confirmed. Large clusters of high biophysical vulnerability are present along all but the Pacific coast. Large clusters of low biophysical vulnerability are found in the intermountain West and Midwest.