基于Visual Modflow的某油库地下水污染模拟

Numerical Simulation of Groundwater Pollution of an Oil Depot Based on Visual Modflow

[目的]对陕西省黄陵县某油库地下水污染状况进行模拟,为油库区地下水污染的辅助预测和防治提供科学指导。[方法]通过野外调查试验获得初始参数,应用Visual Modflow软件建立了地下水水流模型,进行模型识别验证,获得最终水文地质参数。耦合水流方程与污染物迁移方程,得到地下水溶质运移模型。[结果]模拟了两种假设情形下运移情况:正常工况和油罐漏油。数值模拟预测了污染的范围和程度。到预测时间20a,污染物影响范围最大。[结论]污染物主要沿水流方向运移,对水环境的影响随时间逐渐增大,污染浓度随距离增大而减小;两种情况下,油罐漏油时对水环境造成的影响更加恶劣,污染范围远超出油库区。

[Objective] The groundwater pollution status of a depot in Huangling County of Shaanxi Province were simulated to provide scientific guidance for auxiliary prediction and prevention of groundwater pollution in oil depot area. [Methods] Based on the initial parameters obtained through field investigation, we established a groundwater flow model using Visual Modflow software. Then through model identification and verification, we obtained the final hydrogeological parameters. And we derived a groundwater solute trans- port model in reference to water flow equation and contaminant transport equation. [Results] We simulated two hypothetical scenarios： one is under normal working condition and another one is when oil leakage happened for the oil tank. The range and degree of pollution were predicted by numerical simulation. The impact of pollutants was predicted that it would become the greatest in the following 20th year of leakage. [Conclusion] The results obviously showed that the contaminant transport mainly via flow direction, the impact on water environment tends to gradually increase with time going on. And there was a negative correlation between the concentration of pollution and the distance from oil tank. Oil tank leakage will cause more severe pollution to the water environment than normal operation can do, under that case, pollution is far beyond the scope of the depot area.