中文摘要：

钱塘江涌潮前后水位、流速和含沙量等物理量存在突变,给数值模拟带来了很大的困难,常规的数值模型往往不能准确模拟涌潮作用下的泥沙输移。在已建立的二维涌潮数值模型的基础上,应用基于准确Riemann解的Godunov格式建立了二维泥沙数值模型,模型首先检验了纯对流问题,然后模拟了钱塘江涌潮作用下的泥沙输移,计算结果反映了涌潮到达时刻含沙量的突变过程以及涌潮对泥沙输移的影响,揭示了钱塘江河口高含沙区的成因,以及涌潮是钱塘江河口大冲大淤的机理之一。

英文摘要：

As sudden changes of water level,velocity,sediment concentration and other physical variables before and after the tidal bore in the Qiantang River lead to great difficulty in numerical simulation,the traditional models cannot accurately simulate effect of tidal bore on sediment transport.Based on the existing 2D numerical model for tidal bores,a new 2D sediment numerical model was established by using the Godunov scheme based on exact Riemann solver.The validity of this model was verified by a pure convection problem,and then applied to simulate the sediment transport affected by the tidal bore in the Qiantang River.The results reveal the sudden changing processes of the sediment concentration at the tidal bore＇s arrival and the effects of the tidal bore on sediment transport.The findings also find out the cause of the formation of high sediment concentration region in the Qiantang stuary.The tidal bore is one of the mechanisms causing the occurrence of serious erosion and deposition of riverbed in the Qiantang estuary.