Simulation and assessment of compound flooding in coastal cities under climate change

Abstract

Low-lying coastal areas are highly vulnerable to flood hazards, especially under the influence of global warming, and the possibility of compound floods is often much greater than that of individual floods. Understanding the probability of these compound events and the processes that drive them is essential for mitigating the impacts of coastal high-risk areas. Here we use a new simplified physical solver SFINCS model (Super-Fast INundation of CoastS), to computationally efficiently calculate compound floods in coastal areas due to fluvial, pluvial and storm surge driven processes. At the same time, a variety of climate scenarios are considered for the prediction of potential future compound flood patterns. We demonstrated in our application case in Shanghai, China, that the model can simulate a combination of fluvial, pluvial, and storm surge driven floods well. Our results show that the combined effects of future climate change on coastal compound flood hazards will significantly increase the extent of flood hazards, obviously increasing the level of risk at low-risk areas and requiring an integrated response to the consequences of future compound floods. This research has important implications for the assessment of compound flood risk in coastal areas and for climate-resilient flood management.