中文摘要：

采用沿深平均二维数值模型对南黄海辐射沙脊群西洋海域的潮流场和物质扩散场进行了模拟,计算和分析了大潮情况下海域5 m、7 m和10 m 3种水深（理论基准面下）排放位置处达标污水输移扩散的范围及分布规律。结果表明,污水排入海后,会很快被稀释,各排放位置200和500稀释度等值线包络面积均较小,且包络面积随水深增加有明显变小的规律。拟合了不同污水排放量对应的200和500稀释倍数包络面积,发现两者呈良好的幂级数关系。

英文摘要：

By using the 2-D numerical model averaged in the vertical direction which was performed for the tidal currents and pollutant diffusion in the Xiyang channel along the southwestern coast of the Yellow Sea, the influence of permitted sewage diffusion at the effluent discharge points which are located at the water depths of 5m, 7m and 10m（under the theory of datum） respectively during the spring tide were calculated and analyzed. The results showed that the standard of sewage would soon be diluted when it＇s drained into the sea. The envelope areas for both 500 and 200 times of dilutability contour isoline were small. And obviously, the envelope increment was inversely proportional to the water depth. Based on the model, the envelope areas under different discharges for both 500 and 200 times of dilutablity contour isoline were calculated, finding the two variables have a positive relationship in series of power.