The Application Of Curvilinear SHORECIRC In The Numerical Simulation Of Storm Surge In Bohai Sea

The storm surge from the sea is a kind of fearful disaster in nature. It is caused by strong air disturbing, for example tropic cyclone ,temperate cyclone. If it happens to meet with high tide, they cooperate with each other and will cause a big storm surge making a calamity.In this paper, we adopted the Qusi-3D Nearshore Circulation model. This model considers the effect of the vertical distribution of the current velocity. And it is also coupled with the wave model REF/DIF1. But the SHORECIRC model was developed in rectangular Cartesian coordinates and was only used in rectangular domains, thus limiting the applicability of the model to less complicated coastal environments.Based on the Qusi-3D Nearshore Circulation equations, we use a generalized coordinate transformation transforming these equations into a model in curvilinear coodinates.In the numerical simulation, we apply the adaptive grid generation technique developed by Brackbill(1982) and the method of nesting between two different models as well.For different grid points, we also define different point types so as to distinguish different boundary conditions. Then we develop a system of tide prediction in Bohai. We also add in the actual wind field, the surface stress of wind and the open boundary conditions considering the nonlinear effect of tide to storm surge.In this paper we perform two numerical simulation of the storm surge of Bohai in 2003 and 2004.The simulated water level processes are compared with the measured data of Huanghua station. And the result indicates that their trends agree and the model is thus proved to be applicable in the tide and storm tide prediction.Furthermore, we analyse the current field when flood tide or ebb-tide happens, the vertical structure of current, the nonlinear effect of tide to storm surge, and the effect of the friction coefficient to current velocity. By analyzing the result simulated by the numerical model, we point out the correlative factors that effect the simulation precision, for instanse the boundary conditions and the precision of given wind field. Besises, we also point out the limitation of the wave model in simulating the storm surge under strong wind.