Coupling simulation of non-point source pollution and 2-D water quality in Nanhe River

With the rapid growth of urban population and stable growth of GDP in China, non-point source pollution has become an important reason for the deterioration of urban water pollution, which seriously threatens the security of urban ecological environment. In this paper, the coupling model of non-point source pollution and two-dimensional water quality of SWMM in Nanhe region is constructed, and the coupling model is verified, and the verification results are in good agreement with the measured data. The results show that the improvement of water quality of Nanhe River by ecological treatment is limited; the load of pollutants into the river and the maximum concentration of pollutants in Nanhe River can be effectively reduced by source control and sewage interception; under the design conditions, the water quality index will be difficult to reach and recover to the original level after short-term rainfall, so it is necessary to maintain the water quality When the diversion flow is 3m3/s and 5m3/s, the Nanhe River can basically return to the level before rainfall in one day.