Background: Socially vulnerable residents of US Gulf Coast counties have higher exposure to physical hazards and disaster-associated risks. Evacuation is one way to mitigate the consequences of disaster exposure among socially vulnerable populations. However, it is unknown whether existing evacuation shelter capacity and locations in designated hurricane evacuation zones of Texas are adequate to accommodate persons with housing and transportation needs. This study estimated the evacuation shelter deficit arising from demand from socially vulnerable residents of the Houston-Galveston area.
Methods: Spatial statistical methods including Global Moran's I and Getis-Ord (Gi*) were used to measure spatial autocorrelation and identify census tracts in the study area with high (hot spots) and low (cold spots) social vulnerability in both housing and transportation domains. The shelter deficit in each county within the study area was estimated as well as for the entire Houston-Galveston Metropolitan Statistical Area.
Results: Designated evacuation zones in the Houston-Galveston area have an overall shelter deficit of 163 317 persons. Shelters in the area can only accommodate 36% of evacuees with significant housing and transportation needs, while 3 of 4 counties had county-specific evacuation shelter deficits. The highest deficits were in Harris County, where Houston is located, and the lowest were in Matagorda County, a rural county southwest of Harris County.
Conclusion: Emergency managers and other authorities should consider data related to demand from socially vulnerable residents for public shelters during disasters and increase shelter capacity in certain locations to address evacuation shelter shortage for vulnerable persons in designated evacuation zones of Texas.
Keywords: evacuation; hurricane; shelter capacity; social vulnerability; spatial statistics.