Tropical Cyclone Compound Hazard Assessment Under Changing Climate and Development Conditions

Abstract

Quantifying the risk from tropical cyclone hazards requires understanding their climatology at the basin-scale, their wind, surge, and rainfall hazards at the coast, and how the joint hazards interact with each other and the localized features of coastal environments (both natural and human-made). To add to this complexity, the climate and coastal landscape are continuously changing, whether through natural variability, anthropogenic climate change, or human activities such as urbanization. Due to limited observations of TCs in the historical record and the coarse resolution of general circulation models, characterizing TC climatology and risk is challenging, and future projection of TCs is largely uncertain. Moreover, modeling the interactions between TC rainfall and storm surge in coastal catchments, a phenomenon known as compound flooding, is also challenging due to limitations of existing flood models. To improve understanding of historical TC climatology and joint hazards, project joint risk in the future, and improve the characterization of compound flood hazard under evolving conditions, this dissertation develops approaches for quantifying the multi-hazard risk posed by TCs at both the regional and local scales. The methods advanced here center on coupling and/or linking physical and statistical models to efficiently simulate TC compound hazards under changing climate and landscape conditions. At the regional scale we utilize synthetic TC track modeling and physical rainfall, wind, and storm surge models to characterize historical and future joint TC rainfall-surge hazard and risk. We then develop a coupled flood modeling approach at the local scale and implement a joint probability optimal sampling approach to efficiently simulate compound flood hazard under a variety of climate conditions. The work in this dissertation provides a possible roadmap for linking regional-scale projections of TC climatology change to local-scale impacts (such as TC compound flooding).