Mitigation Strategies to Protect Petrochemical Infrastructure and Nearby Communities during Storm Surge

Abstract

This paper explores engineering- and social science-based strategies to mitigate risks posed by aboveground storage tanks (ASTs) during storm events. The Houston Ship Channel (HSC) is used as a case study to illustrate the application of an integrated model of built-human-natural systems and evaluate the viability of alternative risk mitigation strategies for protecting petrochemical infrastructure and nearby communities subjected to storm surge events. First, a model that couples storm surge exposure, fragility modeling, and social vulnerability of communities is used to quantify the effectiveness and economic viability of engineering-based measures to reduce spill risks, such as filling ASTs with liquid, anchoring them to the ground, changing their stiffness, or protecting them with dikes. The results indicate that no single measure is optimal and that combinations of measures could be more suitable. Thus, an optimization approach and a heuristic approach are proposed to select and combine measures considering structural and social vulnerability. Both approaches prove to be effective in reducing storm-induced spills to a given target while minimizing costs; however, they do not improve the resilience of residents in the HSC. Thus, through social science assessment of communities at risk, additional measures are identified, including improved risk communication and evacuation planning, simplified governance structures, moving from equal treatment approaches to equitable treatment approaches, and creating institutions that will empower and benefit local residents. Successful mitigation plans should cut across both engineering and social science approaches.