Graduation Year


Document Type




Degree Name

Master of Arts (M.A.)



Degree Granting Department


Major Professor

Graham A. Tobin, Ph.D.

Committee Member

Robert Brinkmann, Ph.D.

Committee Member

Steven Reader, Ph.D.


Multiple hazard risk and vulnerability are two topics that are at the forefront of hazards research that looks at the hazardousness ofplace. However, no definitive framework that encapsulates measures o f both risk and vulnerability into hazards theory has been developed. Indeed, risk and vulnerability have been used interchangeably. Consequently, populations often encounter high risk environments with little understandingofwaystolimitvulnerability. Thesituationisaggravatedbyincreasing populations and concomitant development ofhigh risk areas. Hillsborough County, Florida, is perhaps the archetype ofthis problem, having experienced rapid urban growth while giving scant attention to the hazardousness ofthe environment.

This research, therefore, looks at the hazardousness of place, focusing specifically on risk and dynamic social conditions of vulnerability. Three goals were identified: the first was to understand spatial patterns of risk from multiple natural hazards by examining parameters ofthe physical environment; the second was to develop a quantitative index of vulnerability within the context of natural hazards differentiated over space; and the third sought to model the combined effects of risk and vulnerability.

Hillsborough County, Florida, was used as the research area. Data on risk from extreme hazardous events, including, wind damage, storm surge, flooding, sinkholes, and hurricanes, were collected from the Arbitrator of Storms (TAOS) files available for the stateofFlorida. Socioeconomicdataforevaluatingvulnerabilitywereobtainedfrom Geographic Information Systems (GIS) coverages ofthe 1990 census. These data included statistics on population density, gender, age, house value, housing density, house structure, and renter occupancy, which were aggregated to develop an index of vulnerability. These various parameters were then used to determine the spatial pattern of hazardousness in Hillsborough County based on census block groups.

Results showed that high hazard risk extended far beyond coastal areas and that virtually all census blocks in the county had some element of risk. The social vulnerability analysis exhibited different spatial patterns with several blocks revealing very high levels of community vulnerability. These areas did not conform exclusively to those categorized as low income. In combination, five census blocks in different parts of the county were identified and shown to have both high risk and high vulnerability.

Thus, combining risk and vulnerability provided a different picture of the hazard problem and should be the focus of further research. From an academic perspective it is now important to test these findings under more rigorous conditions to see if the model stands in other hazard environments. In addition, the findings from the model can also be useful to planners and managers as they consider how to respond to hazards. Identifying vulnerable areas prior to disaster events would greatly facilitate efficient responses.

Included in

Geography Commons