NUMERICAL SIMULATION OF TIDAL CURRENT AND POLLUTANT DISTRIBUTION OF BOHAI BAY

Bohai Bay is a typical semi-closed bay in the western Part of Bohai Sea The main characters of the bay are very shallow water depth, wide mild slope mud beach, and heavy pollution loads. In this paper, 2-D depth-averaged hydrodynamic model and advection-diffusion model with moving boundary are used to simulate the velocity field and pollutant distribution of Bohai Bay. In order to beat the moving boundary following the hdal rise and fall, hydrodynamic equahtions and advection-diffusion equation using the slot method are used.) Hydrodynamic model Mass equationwhere are the unit discharge in x and y directions respectively; Z is water elevation and α are paramters, Z is seabed elevation.Momentum equalions are of the same form as that without slot.2) Advection-diffusion model Where. C is Pollutant concenimtion parameter; H is water depth Z0 is slope bottom elevati on; Sm is source term; Ex Ey are diffusion cocefficient in x and y directions respectively. The very small difference between the observed data and the numerical results for velocity and pollutant concentration distribution showed that the models presented in this paper are reliable, especially for the boatment of moving boundary conditions. The above models were used to investigate the environmental capacity, division of function area and oceenic disposal of wastewater of Bohai Bay.