【作者】 王莉；

【导师】 田良；

【作者基本信息】 兰州大学 ， 环境科学， 2006， 硕士

【摘要】 随着水环境问题的日益突出和水资源保护工作的深入进行,在大力开展水质模型理论研究的基础上,如何提高水质模拟技术的应用研究显得更加重要。本文针对环境影响评价中的确定性水质模型展开研究,在水质模拟预测技术理论联系实际方面有所深入和创新,研究领域涉及环境科学、地质科学、水文科学、现代应用数学和计算机技术的交叉应用学科范畴。论文主要包括五方面内容: 第一,对确定性水质模型进行概括梳理,包括模型方程、各种情况下的解析解和模型主要参数的确定方法。 第二,分别针对地表水水质模型（S—P模型）和地下水水质模型（三维瞬时点源排放模型）进行参数灵敏度测试。主要结论为:在S—P模型中,对BOD而言,参数灵敏度排序为L₀>u>K₁>E;对DO而言,参数灵敏度排序为O_s>O₀>（u,L₀,K₁,K₂）>E。在地下水三维瞬时点源排放模型中,参数灵敏度排序为（n_e,u）>（K_d,ρ_b,λ）>（m,σ_x,σ_y,σ_z）。 第三,在S—P模型失效的情况下,采用分段求解和非稳态四点隐式差分体系求解两种方法,所得结果较好,能够解决S—P模型失效时的模型求解问题。 第四,采用—维数值解（四点隐式差分离散）和二维解析解（累积流量法）两种方法对2003年3月黄河兰州段25km长区域的COD_cr浓度进行现状模拟。主要结论为:①研究区纵向离散系数E为48km²/h。②两种方法对中山桥断面的水质模拟效果都不错,但两种方法又各有优缺点。一维数值解法求解过程是动态的,能更形象的模拟污染物浓度的迁移转化,但却损失了断面上的浓度变化细节。二维累积流量法对污染物浓度迁移转化的模拟精度大大高于一维模型,但求解过程是静态的,且需要的数据也多于一维模型。 第五,采用三维连续点源排放模型和二维瞬时面源模型,对事故状态下某输油管线石油类污染物在地下水环境中的迁移扩散情况进行预测模拟。主要结论是:在污染最严重的Z=0层面,管线穿孔泄露100天,沿水流方向上70m处污染物达标,10年后污染带延伸到555m;管线爆裂1年后纵向超标范围可达210m,10年后整个区域均达标。证明穿孔泄露对地下水环境的影响比管线爆裂更严重。更多还原

【Abstract】 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.更多还原