Numerical Simulation of the Tidal Currents and the Contamination Diffusion near Xiaoyangkou in Radial Sand Ridges Area of the Yellow Sea

摘要

The main researches of radial sand ridges in north Jiangsu are focused in the forms of morphogenesis and the characteristic of conformation of sand ridges. There are few studies on the material transport in radial sand ridges. A finite element method for the numerical simulation of the dilution and diffusion of the sewage outlet near Yangkougang was considered in this paper. Chemical oxygen demand (COD) was selected as the reference computation factor of contamination transport. Based on the computed tidal current field, the distributions of COD concentration near south coast of north Jiangsu were simulated. Comparison between computation results and the observed data indicates that this model could reasonably simulate the tidal current, tidal currents in part of waterways which are in sandbank ridges obviously have to-and-fro movement, and strong tidal current and great tidal range occur; the range of contamination diffusion derived from sewage outlet is very limited, and the influence range of sewage comes to the maximum when ebb slacks in neap tide period.