THREE DIMENSIONAL MATHEMATICAL MODEL OF SEDIMENT TRANSPORT IN ESTUARINE REGIONS-A CASE STUDY OF THE HAIHE RIVER MOUTH

A 3-D numerical model for simulating tidal flow and sediment transport in the estuarine regions is presented in this paper. The model adopts -coordinate system and carries out -coordinate transformation to the basic equations, which ensure that all horizontal area has equal numbers of calculation points in vertical direction, this method provides higher distinguishable rate to the flow and sediment transport. Under the -coordinate system, the Galerkin finite-element method is applied for horizontal domain by using a new specially interpolating shape functions, while a finite difference approximation is employed over depth. The model can be used even in the situations with a considerable variety in the water depth in the computational domain. The model is verified by a test for which analytical solutions are available and then applied to simulate the tidal current and sediment transport of the Haihe River Mouth. A modeling system of sediment transport is established for applying to muddy estuary of North China. The comparison with the field data shows that the model can well simulate the evolution process in the estuary.