Abstract:

Planning for controlling the sewage discharge of the point pollution sources around the river is complicated with both macro and micro factors.According to this characteristic,a multiobjective planning model based on simulating the course of pollutants diffusion and linear programming is presented to plan the sewage of several main pollutants from the point pollution sources and to define the corresponding requirement of controlling each pollution sources,which can be used as the basis for decision making of water environment management.In the case study,this coupled modeling approach is applied to plan the sewage of COD and NH4N from 6 point pollution sources around the Yibin section of the Minjiang River and the sewage planⅠ can be defined. Considering the results of the sewage plan Ⅰ and the characteristics of the waste water,the outlets of the pollution sources can be rearranged,and then the sewage plan Ⅱ can be obtained through the modeling approach.After comparing the pollution contribution of COD and NH4N to Minjiang River and the Yangtze River in the condition of implementation of no planning, the sewage planⅠ and the sewage planⅡ,the results show:the pollution contribution of COD and NH4N to the Minjiang River and the Yangtze River can be reduced considerably and the water environmental quality of the study area meet the standard in accordance with both two sewage plans.The sewage planⅠ can take fuller advantage of the water environment capacity of the study area and need lower investment for pollution controlling;while the sewage plan Ⅱ need to invest more to raise the intensity of pollution controlling of 4 new outlets,but it can offer more water environment capacity for regional development.〖