Numeric Simulations of the Pollutant Diffusions of Sewage Outfalls in the Yangtze River Estuary
There is complex topography in the Yangtze River Estuary (YRE),where hydrodynamic process is also extremely complex.It is difficult to simulate three-dimensional pollutants diffusion in the YRE.In this paper,based on three-dimensional ocean model (FVCOM)and the tracer-tracking technology,simulated the pollutant diffusions of sewage outfalls (Shi Dongkou,Zhu Yuan,Bai Long-gang,and Xin He)in the Shanghai,analyzed of pollutants diffusion characteristics and influence scopes in the surfaces,middle,bottom layers in the YRE.The results showed that there is not obvious differ-ence in vertical distribution of pollutants diffusion in the YRE.Due to greater effect of Yangtze River runoff on pollutants diffusion in the YRE,although horizontal diffusion distribution oscillated move-ment by tide,the overall diffusion trend is to the YRE.After pollutants diffused out of the YRE,pol-lutants are greatly influenced by the tide.Pollutants gradually were diffused to out to sea.Finally some pollutants can be diffused into the Hangzhou Bay.Pollutants can effect on coast nearby sewage out-falls,Chinese sturgeon nature reserve,Jiuduansha shoals wetland national nature reserve,little effect on source of drinking water in Shanghai.
sewage outfallspollutant diffusionFVCOMsimulationYangtze River Estuary