COASTAL FLOOD RESILIENCE ANALYSIS FOR COMMUNITIES AND MEGACITIES

Abstract

Coastal regions are subject to threats, especially storm surge flooding, extreme winds, and heavy rainfall. These impacts will likely become more severe with the coupled effects of climate change and coastal development. Enhancing coastal resilience is a critical concern, requiring an understanding of both the physical risks and human behavior.

This dissertation aims to integrate science and engineering to develop advanced coastal risk mitigation strategies, accounting for potential effects of climate change and considering economical feasibility, social equality, and human behavior in decision making. It proposes a suite of methodologies to evaluate the impact of extreme weather events and model decision making processes. These include scientific studies to characterize flood risk, engineering designs to mitigate the risk, and decision-making analysis to understand risk perception. To evaluate the impact of hurricanes to the built environment, damage assessment from previous events (Hurricanes Sandy in 2012 and Irma in 2017) is conducted, providing a basis for analyzing damage features and developing vulnerability models. Applying risk assessment considering both vulnerability and hazards, an economically optimal risk mitigation strategy, which combines risk transfer and engineering risk reduction measures, is proposed. The influences of the past protection, future optimal strategies and potential regret in risk mitigation decisions are then investigated. These analyses provide a solid methodological framework that can assist policy makers in decision making.

However, neither policy makers nor the general public may be perfectly rational as the classical economic models predict. The interactions between human factors and risk management strategies are complex. Understanding human factors therefore is a critical step for any risk management plan to be implemented. Risk perception and behavioral decision-making are therefore analyzed for coastal residents using empirical analysis and advanced statistical models. Using a Gulf Coast survey dataset, people’s risk perception towards hurricane strength, their voluntary flood insurance purchase behavior, and their support for flood adaptation policies are investigated. The analyses provide insights in understanding key human drivers in decision processes. The analyses also lay out a foundation for combining objective risk assessment with subjective human judgement in a rigorous way in the future.