Revealing disaster dynamics and disparities in urban facility accessibility using an improved utilization-based metric

Quantifying socio-spatial disparities in accessibility to urban facilities is a crucial step toward achieving the Sustainable Development Goals (SDGs) of universal access to these facilities. Drawing on mobility big data in Wilmington metropolitan area in the United States, we proposed a novel dynamic utilization-based accessibility metric based on the traditional gravity model, and assessed the residents' grocery store accessibility and restaurant accessibility before, during and after Hurricane Florence in 2018, revealing disparities in residents' access patterns. Then, we investigated the roles of potential accessibility and neighborhoods' demographics and socioeconomic status in explaining the residents' accessibility both in the normal state and during the hurricane. Notably, our findings show that, despite a general decline in accessibility during hurricanes, our metric adeptly captures varying extents of disruption across different facilities. A surge in spatial inequity of restaurant accessibility was observed alongside reduced spatial inequity levels in grocery store accessibility. Interestingly, while normal-state grocery accessibility hinges on aspatial factors like median income and race, “potential accessibility” as a spatial factor emerges as the most significant determinant during the hurricane. The findings provide new insights for city planners and policymakers to promote sustainable mobility and resource allocations for social justice in emergency response.