Large-scale modeling of hurricane flooding and disrupted infrastructure impacts on accessibility to critical facilities

Post-hurricane accessibility to critical facilities is crucial for accelerating the recovery process, which can often be disrupted by hurricane-induced flooding. The State of Florida is especially vulnerable to flooding accompanied by hurricanes, which leads to significant roadway closures and accessibility challenges that require special attention. As such, this research aims to analyze changes in accessibility to critical facilities due to Hurricane Irma-induced flooding. Accordingly, this research aims to compare the average accessibility changes to critical facilities for vulnerable populations, including older people, disabled people, and older people with a disability with the general population. To accomplish these goals, flood mapping was done by analyzing Sentinel-1 images before and after Hurricane Irma (2017) using Google Earth Engine. The accessibility change from block groups to critical facilities was analyzed using a cumulative opportunities approach in GIS, considering flooded areas as the barriers, which were later aggregated to the county level. Finally, employing the population-weighted average accessibility method, a comparison of accessibility change of vulnerable and general populations was conducted. The result shows that 1193.80 square km of areas in 43 counties of Florida, mostly in the southern portions, were affected by flooding after Hurricane Irma. Later, the accessibility changes to critical facilities considering 15-min and 30-min travel time thresholds are presented and visualized. The county-wise change in accessibility of vulnerable and general populations was also computed. The knowledge acquired from this research can improve the development of efficient and equitable post-disaster recovery plans.