Numerical simulation of topography change in reclaimed land along coast of South China Sea

A formula for total sediment transport rate was worked out based on field surveys and experiments, which could be used to predict the topography change under wave climate. The sediment transport and wave induced hydrodynamics were solved separately, which is more convenient to predict long-term beach evolution than solving a coupled equation. In applying the sediment transport equation to wave model, the topography change was considered to give a new bathymetry as input for the wave equations, which in return will give a time-dependent hydrodynamic environment. The wave transformation including wave breaking was simulated by solving Boussinesq-type wave equations, together with some verification and comparisons. The longshore currents due to eddy viscosity was simulated by the model under unidirectional waves, which have been applied in erosion control of reclaimed land by headland breakwaters. The topography is found in equilibrium by headland breakwaters and the equilibrium process is simulated with comparison to the engineering practice in the South China Sea.