Numerical Simulations of Coastal Flood and Morphological Change Due to Hazardous Hydrological Conditions at Coast and Estuary

By applying an integrated coastal processes model, this paper presents a numerical simulation example to present coastal flooding and morphodynamic responses to an extreme river flood driven by a hazardous typhoon event (with a 100-year return period) at an estuary and its adjacent coast. Numerical results revealed complex flood flow patterns and morphological changes in the estuary, e.g., bank overflow, coastal inundation, erosion/deposition, as well as breaching of a rivermouth sand bar. The differences of the predicted results between the cases with and without morphodynamic modeling are also discussed. It indicates that the coastal flood simulation results without the consideration of morphological changes (a hard bottom) may underestimate coastal flood and inundation. These results are important to the understanding of coastal flood, sediment transport, and morphodynamic processes during hazardous weather conditions, and furthermore, can be used for planning for flood protection, sediment management, and shoreline stabilization in the region.