| 数值法与解析法在地下水环境影响评价中的应用研究 |
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| 作者单位： | ;1.四川大学水力学与山区河流开发保护国家重点实验室/水利水电学院 |
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| 摘 要： | 【目的】探究数值法与解析法在进行地下水环境影响评价时的差异,以及在进行地下水环境评价时,选择更为合适的计算方法。【方法】以四川省宜宾市某氯化法钛白粉项目为例,利用瞬时点源一维对流扩散模型、瞬时点源二维扩散模型和GMS数值模型研究非正常工况下苯储罐泄漏时污染物对地下水的影响,预测了污染物在潜水含水层中的中心运移距离、最大浓度和污染范围,并对3种方法的计算结果进行比较分析。【结果】一维对流模型只考虑地下水流向方向上的运移情况,计算结果最大,方法简单方便,参数要求较少,但精度较低,无法预测污染面积;二维扩散模型考虑了平面上的污染物分布情况,可以预测污染物范围及浓度变化,但预测运移距离较大,与实际的边界条件矛盾;GMS数值模型是三维模拟,计算精度高,更符合实际情况,但建模过程复杂,水文地质条件限制较多,所需水文地质参数较多,耗时较长。【结论】综上考虑,水文地质条件简单、地下水环境评价等级不高的工程项目使用解析法预测较为方便;在水文地质资料充足、评价等级高的区域使用数值法预测精度更高。
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| 关 键 词： | 地下水 模型 环境影响评价 解析法 数值法 |
Application of Numerical Method and Analytical Method in Groundwater Environmental Impact Assessment |
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| Institution: | ,State Key Laboratory of Hydraulics and Mountain River Development and Protection,Sichuan University/Institute of Water Conservancy and Hydro-electric Power |
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| Abstract: | 【Objective】The aim is to explore the differences between numerical method and analytical method in environmental impact assessment of groundwater, and find a more appropriate calculation method.【Method】Taking a Chlorinated Titanium Dioxide Project in Yibin, Sichuan Province as an example, three computing methods:one-dimensional convection-diffusion model of instantaneous point source, two-dimensional diffusion model of instantaneous point source and GMS numerical model were used to study the influence of pollutants on groundwater when benzene tank leaks under abnormal conditions. The central migration distance, maximum concentration and pollution range of pollutants in unconfined aquifer were predicted, and the results of the three methods were analyzed and compared.【Result】The first method only considers the movement of groundwater flow direction,while its calculation accuracy is not good enough. But this method is simple and convenient, and the parameters are less required. The second method takes into account the distribution of pollutants in the plane,and can predict the range and concentration of pollutants. But the prediction of migration distance is too large,which is inconsistent with the actual boundary conditions. GMS numerical model is a three-dimensional simulation, which is with high accuracy and can accords with the actual situation. But the modeling process is complex and the hydrogeological conditions are more limited.【Conclusion】In summary, it is convenient to use analytic method to predict projects with the simple hydrogeological conditions and low level of groundwater environmental assessment. In areas with abundant hydrogeological data and high level of evaluation, numerical method is more suitable. |
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| Keywords: | groundwater model environmental impact assessment analytical method numerical method |
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