In the framework of the co-operation project on marine science between Hai Phong city and Brest city (French) in period 2008-2010, the simulation of tramportation of pollutants in coastal estuary area of Hai Phong had been studied. This paper uses the model Delft-3D (Delft Hydraulics, The Netherlands) to simulate the transportation of pollutants in the water body such as total suspended solid (TSS), organic matters (BOD, COD), nutrients (NH4, NO3, PO4). The result from model shown that the dispersed of total suspended solid from inland occur mainly in rainy season and the transported trend is more dominant in the southwest-south than in the northeast-east
the influence of total suspended solid to surface water layer is stronger than that in the bollom layer, The flow of organic matters and nutrients from Hai Phong rivers is less influnce to outside of coastal area (the south of Cat Ba and Cat Hai islands) in both rainy and dry seasons, While, in the rainy season, the water mass contains high value of organic matters ana nutrients from inlands to sea is much influence to the south of coastal zone and rivers mouth, including Do Son beach and the southwest of Van Uc river mouth.