基于MIKE耦合模型的典型平原感潮河网地区排污口水环境影响研究

Environmental Impact of Sewage Outfall in Typical Plain Tidal River Network Area Based on MIKE Coupling Model

为探究长江三角洲平原感潮河网地区入河排污口设置对水环境的影响,以泰兴市某工业园区排污口为例,基于MIKE11及MIKE21建立水动力水质耦合模型,模拟COD,NH3-N,TP等目标污染物的迁移转化,分析不同污染物浓度扩散规律。结果表明,经率定验证后的耦合模型水动力模拟精度较高,水质模拟误差PBIAS小于25%,可较好的适用于计算区域多元污染物的迁移转化模拟;排污口尾水正常排放后两条入江河流五、六圩港水质均达到地表水Ⅲ类标准,事故排放时污染物入江通量显著增加;入江污染负荷的增加使长江污染物高浓度区域占比增大,涨潮时污染带有明显上溯趋势,落潮时最远可扩散至六圩港入江口下游1.05 km。

In order to explore the influence of the drainage outlet in the tidal river network area in the Yangtze River Delta plain on the water environment,taking the drainage outlet in an industrial park in Taixing City as an example,a hydrodynamic and water quality coupling model was established based on MIKE11 and MIKE21 to simulate the migration and transformation of target pollutants such as COD,NH_3-N and TP,and analyze the concentration diffusion law of different pollutants.The results show that the coupling model after calibration verification has high hydrodynamic simulation accuracy,and the water quality simulation error PBIAS is less than 25%,which can be well applied to the simulation of migration and transformation of multiple pollutants in the calculation area.After the discharge of the tailwater from the sewage outlet,the water quality of the two rivers reached the level of Class Ⅲ of surface water,and the pollutant flux into the river increased significantly during the accident discharge.With the increase of pollution load into the Yangtze River,the proportion of high-concentration pollutants in the area of the Yangtze River increases.At high tide,the pollution had an obvious upward trend while it could spread as far as 1.05 km downstream of Liuwei Port at low tide.