Numerical Simulation Analysis Of Water Quality Of Huai River In Huainan

Huaihe is one important river of water pollution management on Three Lakes and Three Rivers in China.With the development of economy, the living sewage and industrial waste water into Huaihe River is increasing day by day,the water-pollution problem in Huaihe becomes more and more severe. So hydrodynamics and water quality modeling technique, which is an important means for understanding the statusquo and problem of water environment, has been extensively applied in the trend analysis of Numerical simulation of Pollutant Diffusion-Transportation and programming and management of water environment.Numerical computation in this paper bases on the theory of shallow water hydrodynamics. Considering the width is much more than the depth in natural river, the assumption that the horizontal flow velocity in the calculated domain is depth-average ignoring the vertical velocity and acceleration, is taken in this paper. The 2D shallow water equation, which is depth-integrated of the 3-dimensional incompressible fluid movement equations, is applied to describe the river's flow.Finite element model is applied to the numerical computation, using the Galerkin method of weighted residuals to discrete the hydrodynamics and water quality governing equations. The two kinds of governing equations are solved by combination.In this paper, RMA2 model and RMA4 model are introduced to the reseach of Huaihe water environment. This paper takes the downstream of Huaihe River from gongtie bridge to tianjiaan as study object,NH3-N,CODcr as pollutant index.the result shows that:It is feasible to analyse the chang of NH3-N and CODcr in tianjiaan using the 2-dimensional RMA4 model .Take sewage discharging at riverside for example,We'd better control the discharge capacity.In the early stage of sewage discharging, it forms a pollutant band at the boundary near the discharging point. Then it will diffuse entirely in the whole river way in the downstream. So it is suggested that the sewage should be cleaned before discharged, so as to make the water quality of the downstream up to standard.