【作者】 唐莲；

【导师】 白丹；

【作者基本信息】 西安理工大学 ， 环境工程， 2004， 硕士

【摘要】 针对石嘴山市利用中水灌溉绿化带问题，采用室内实验与数值模拟分析相结合的方法，研究了污染物NH₄—N，P在灌溉入渗条件下在土壤非饱和带中的迁移和累积规律并利用数学模型对长期灌溉条件下的溶质运移规律进行模拟及预测。研究成果对缓解城市用水紧缺矛盾，保护生态环境具有重要的意义。主要研究成果有： 1．考虑对污染物运移最不利的灌溉及降雨情况，研究污染物的分布规律结果表明：对于污染物氨氮磷素而言，其在土壤中的影响范围随灌水定额的增大灌水次数的增加而扩大污染物的分布范围与水分的分布范围基本一致，但在土壤的吸附作用下，这两种污染物主要集中在土壤上层的一定范围内，水量与灌水次数对它的影响小于暴雨的淋洗作用；在采用节水灌溉方式时，长期的灌溉将使土壤中污染物的累积量增加，但对于迁移而言，影响不大，在地下水埋藏很深的地区，不会成为地下水污染的潜在威胁。 2．根据试验测得的参数值，建立了灌溉入渗条件下的一维土壤水分运动污染物运移的数学模型，并利用有限差分法，借助Matlab数学软件包编程求出其数值解结果表明：模拟值和实测值总体较为一致，可对不同初边界条件下的水分、污染物迁移进行模拟和预测。更多还原

【Abstract】 Aimed at the problems resulting from the middle water irrigation, The soil water movement and solute transport(NH4-N, P) in the soil column under different irrigation frequencies quantities and so on are investigated in this study. Meantime, the mathematical model of water transport and the transformation of NH4-N, P in unsaturated soil are established and solved by the characteristic finite difference method. The research results will form a basis for long term prediction.1. The contamination distribution under the worst irrigation condition was discussed. Such as the effect of different irrigation ratio and rainstorm. From the experiment data we can get: Spread area of solute was the same as water movement. But, four kinds of irrigation frequency have various influence. Another phenomena should be considered, most of NH4-N, P can not moved deeply in soil but cumulate at upper layer of soil. That is to say, the adsorption of soil for NH4-N, P leads to the result that transportation of solute lags behind water movement. At the same time, the infiltration and leaching under rainfall play a more important role on contamination transformation than on water quantity. According to the analysis of laboratory experiments, except the cumulate of contamination in soil for a long time, the middle water irrigation willnot endanger deep embedding underground water if we take account of water saving irrigation methods.2. On the basis of key parameters that drawn from the test results, the mathematic modeling of water movement and NH4-N, P transportation was established. Programs were made to get the numerical solution by Matlab software. In general, The calculated results agree with the observed data. This model can simulate and forecast the solute transportation in a long run.更多还原