Historic and Future Probabilistic Tropical Cyclone Flood Hazards for the Carolinas

In this project, we simulated water levels across eastern North and South Carolina, USA from thousands of synthetic tropical cyclones (TCs) in a historic and projected future climate. We leveraged multiple physics-based models to generate the boundary conditions (i.e., rainfall, wind, storm surge) to a hydrodynamic model (SFINCS) where we simulated 3 scenarios: runoff-only, coastal-only, and total. We used the maximum water level outputs from these 3 simulations to attribute peak water levels to runoff, coastal, or compound flood processes. We generated historic and projected TC probabilistic flood hazard maps to investigate how changes in TC climatology might shift flood drivers and hazards in our study area. We find that considering compound flood processes is important and that sea level rise could move these area inland and upriver. The modeled water levels here can be used to do local level analysis on probable flood events. We use a Monte Carlo approach and our probabilistic maps consider a large number of possible storms and can be used to provide context to traditional design-storm or event-based approaches to estimating flood hazard probabilities. The data can also be used with other environmental or socioeconomic data to assess different exposures and risks to TC flooding.