The Xiamen Symposium on Marine Environmental Sciences (XMAS 2025)

68 / 2024-09-04 20:51:11

Impact of tropical cyclones on the hydrodynamics and sediment dynamics of the radial sand ridge system in the southern Yellow Sea

Numerical modeling,Radial sand ridge system,Tropical cyclone,Lekima,Sedimentary dynamic processes,Morphology change

Estuarine circulation and wave effects play important roles in the hydrodynamics and sediment dynamics in the coastal areas, by influencing the suspended sediment concentration and sediment transport. This study took the Yalu River Estuary in China and Batemans Bay in Australia as typical examples, and introduced the baroclinic and wave effects on coastal hydrodynamics and sediment dynamics based on the method of numerical modelling. The model results show that  (1) the two-layer estuarine circulation can influence the sediment transport and contribute to the formation of turbidity maximum zone, mainly caused by the combined effects of density driven flow, asymmetric tidal mixing driven flow, non-linear advection driven flow and river induced flow; and (2) the strong gradient of wave radiation stress can generate wave-driven flow and control the sediment dynamics and morphological evolution in coastal areas with shallow water and small tidal range. Although site-specific, these findings have wider implications for sediment dynamics in other estuaries.