Climate change exacerbates compound flooding from recent tropical cyclones

Abstract Tropical cyclones (TCs) generate substantial damage raising concerns about how climate change may amplify their impacts. However, linking changes in TC characteristics (wind, precipitation) to shifts in flood hazards and exposure, particularly due to the interaction of multiple drivers, is challenging. In this study, we use highly resolved physics-based models to investigate how flooding from three recent TCs in North and South Carolina would change under 4 degrees Celsius of warming. Runoff processes are the largest contributor to the total flood extent in both the present and future. However, the relative contribution of compound processes increases in the future, expanding upriver and beyond the floodplain where runoff processes previously occurred in isolation. The total area exposed to compound flooding increases by 119% and flood depths in these areas increase by 0.8 m highlighting the importance of simulating compound processes in TC flood exposure assessment.