Evolution of Social Vulnerability and Risks of Chemical Spills during Storm Surge along the Houston Ship Channel

Abstract

Industrial infrastructures such as aboveground storage tanks (ASTs) have suffered major damage in past hurricanes, affecting not only the environment but also the well-being of communities. This study presents a framework to assess the risks associated with hazard exposure to such infrastructures and to uncover the interactions between them and nearby communities over time. The Houston Ship Channel (HSC) is used as a case study. First, an inventory of all ASTs located in the HSC is assembled, and fragility models are used to assess the structural vulnerability of the inventory and estimate the spills for three surge cases. Indicators of social vulnerability are then computed in areas subject to spills. The coevolution of social vulnerability and infrastructure risk is finally assessed by looking at the correlation between these indicators and the spill potential. Results show that for severe storm events, the risk of spills has increased substantially since 1970, owing to the shifts in inventory characteristics and siting. In parallel, communities along the HSC have also become more socially vulnerable. This increase in social vulnerability has become a distinguishing characteristic of these communities compared to others in the surrounding metropolitan area. Lastly, this study finds that the most disadvantaged communities within the HSC are now distinguishable from the less disadvantaged ones by their higher exposure to potential storm-induced spills.