Numerical Simulation Of Sediment Transport In Estuary And Coastal Areas

Sediment transport is an important component of estuarine and coastal engineering research. In china, many estuarine and coastal areas are covered by fine silts and mud, and there are a lot of sediments to be suspended and transported under the action of tidal current and wind waves. Sediment transport problem have an influence on location selection of port, layout of port, waterway dredging , seashore erosion, design of reclamation project, safety of ocean engineering construction and so on. As the development of economic, emission of pollutant and environmental protection become more and more important, these are also closely related to sediment transport problem.Physical model experiment and numerical modeling are two methods to study sediment transport. Compared to physical model experiment, numerical modeling has the advantage of free similarity scale, low cost, high computation efficiency, especially suitable for multi-factor, large areas, multi-option engineering problem.In this thesis, a two-dimensional sediment transport model in estuary and coastal areas is developed. The model is composed of three modules: a hydrodynamics module based on the nonlinear shallow water equations, a suspended sediment transport module and a seabed deformation module. The hydrodynamics module is solved with the alternating directional implicit (ADI) algorithm to obtain the water level and the current velocity. In the suspended sediment transport module, a splitting technique is used to solve the sediment transport equation.The numerical model is tested by simulating tidal flows and suspended sediment transport in Huangmaohai estuary which located in southeast China. The tidal currents, the suspended sediment concentration and the change of the seabed predicted by the numerical model are compared with field data measured in five field sites. And the results show good agreement between the numerical predictions and the field measured data.Finally, the model is applied to Dayaowan bay to study sediment transport process induced by tidal current.