An Application Study On Common Water Quality Model In EIA

With the development of water environment deteriorating and protection of water resource, on the base of developing water quality model research in a big way, how to seem more important to improve the application study of water quality simulation forecasting technology. This paper studied according to certainty model in EIA. At aspect of integrate theory with practice, this paper has some deeply research and innovation. The study field of this paper is involved in the cross-applied sciences, domain of geology, hydrology, environment, modern applied mathematics and computer technology. The content includes five aspects:Fist, carries on the summary to the certainty water quality model, including the equations of model, the analytic solution in various conditions and the method to confirm primary parameters in model.Second, aim at S-P model (surface water quality model) and three-dimensional instantaneous point source discharge model (groundwater quality model), to test the sensitivity on parameters. The main conclusions: In S-P model, the order ofparameters sensitivity for BOD is L₀>u>K₁>E;for DO is O_s>O₀>(u,L₀,K₁,K₂)> E. In three-dimensional instantaneous point source discharge model, the order of parameters sensitivity is (n_e,u) >(K_d,ρ_b,λ) > (m,σ_x,σ_y,σ_z).Third, in condition of S-P model invalidation, use two methods to resolve this problem, which one is section the solving progress, and another use numerical method to get solution (four-point implicit difference method).Forth, use one-dimensional numerical method and two-dimensional analytic solution to simulate COD_cr for the area of 25km at Yellow River trunk's Lanzhou, in March 2003. The main conclusions: (1)The best E in research area is 48 km²/h.(2) Both of two methods have a good simulation solution, but each have merits and faults. One-dimensional numerical solution process is dynamic, which can simulate contamination's transference more vivid, but neglect the details of concentration variation on the section. Two-dimensional cumulated flow method has a more exact stimulant precision, but the progress of solving is static, and this method need more data than one-dimensional model.Fifth, use three-dimensional sequence point source discharge model and two-dimensional instantaneous surface discharge model to forecasting simulate oil transference and diffusion in groundwater environment, on which a pipeline seepage or broken. The main conclusions: At lay of Z=0, which the pollutant is the most serious, after 100 days later, in the stream direction, concentration of pollutant will out of standard in 70m, and will extend to 555m after 10 years. In the condition of pipeline broken, one year later, will out of standard in 210m, and the whole region will agree with standard after 10 years. It's proved that seepage do more harm than broken to groundwater environment.