A Three Component Hazards of Place Model
Identifying vulnerable areas within a community is a critical requirement for emergency planners to develop plans and strategies to protect the community they serve. This requirement can only be met if all components of vulnerability are considered due to the multi-faceted nature of the concept of vulnerability. To date, researchers integrate geophysical risk and social factors for assessing place vulnerability. While integration of geophysical vulnerability and social factors based on the Hazards of Place model provides a general framework for vulnerability analysis, a critical component of vulnerability - evacuation difficulty - has been ignored. In response to hazards, the affected communities have the option to evacuate. The faster the communities can evacuate the lesser the vulnerability. Therefore, researchers need a model that can combine evacuation processes with geophysical risk and social vulnerability to assess community vulnerability. This study introduces and implements a new vulnerability model called the Three Component Hazards of Place that combines evacuation processes with geophysical risk and social factors in assessing overall vulnerability of a place using Hillsborough County, Florida, as a case study area. Using a geographic information systems (GIS) framework, the model combines geophysical risk, social vulnerability, evacuation difficulty indices, to determine the overall vulnerability of Hillsborough County. It was observed that the general distributions of geophysical vulnerability, social vulnerability, evacuation difficulty, as well as overall vulnerability within the county, are dynamic and vary spatially. The study further investigated (both statistically and visually) whether the output of the Three Component Hazards of Place model was different from that of the Hazards of Place model. The results indicated significant differences between the outputs of the two models. It was also observed that while the two models effectively identify areas that receive a greater portion of their vulnerability from geophysical and social factors, the Hazards of Place model underestimated the vulnerabilities of locations that receive a greater portion of their vulnerability from evacuation processes. Underestimation of locations' vulnerability puts pressure on the resources of the hazard mitigation agencies and can have serious unintended consequences including hazard induced fatalities. Theoretically, introduction of the Three Component Hazards of Place model fills the gap in hazard and vulnerability research that has been left by other vulnerability models such as the Risk - Hazard model, the Pressure and Release model, and the Hazards of Place model. This research, therefore, improves our ability to understand the dynamic and multi-faceted construct of the concept of vulnerability. In a practical sense, the Three Component Hazards of Place model presents emergency planners with a better method of selecting vulnerable areas for disaster mitigation measures. By considering evacuation difficulty together with geophysical and social vulnerabilities, emergency planners can reduce underestimation of a location's vulnerability which can help in saving lives and resources.
hazard mitigation, risk assessment, geophysical prediction, population geography, disasters, geophysics, Florida
Yorke, C. (2010). A three component hazards of place model (Unpublished dissertation). Texas State University-San Marcos, San Marcos, Texas.