Numerical Study of Nonlinear Tide-Surge Interaction in the Coastal Waters of Shanghai

Using conventional two-dimensional nonlinear shallow water equations and the associated semi-momentum finite difference schemes, the nonlinear interaction between storm surges and tides, caused by eight tropical cyclones of different tracks over the coastal waters of Shanghai is numerically studied in this paper. The contributions of various nonlinear terms in the dynamic equations to the water level heights is diagnostically analyzed in detail. It is shown that the nonlinear bottom friction term is of prime importance in controlling the water level and nonlinear tide-surge interaction. The correction to the water level and storm surge due to tide-surge interaction is significant.