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重非水相流体(DNAPL)在地下介质中的运移分布受多种因素影响,包括DNAPL的物化性质、泄漏速率、地下水流速和介质非均质性等。本文采用地质统计方法生成渗透率随机场刻画非均质性,运用T2VOC模拟不同流速情形下DNAPL在均质/非均质介质中的运移分布,以评估地下水流速和非均质性对DNAPL运移的影响。研究结果表明,地下水流速的增大显著促进了DNAPL的水平和垂向运移。相同流速情形下,非均质性的增强使得DNAPL污染羽分布形态及运移路径的空间变异性增强,出现明显的蓄积和绕流。当DNAPL运移的优势通道方向与流速方向相反时,水流对DNAPL水平运移的促进作用将减弱,反之,其促进作用增强。随着流速与非均质性的同时增强,水平方向上污染羽的扩散范围增大,另外水平和垂直方向上质心位置(一阶矩)及展布范围(二阶矩),污染池起始位置及其长度的空间变异离散程度增大。
The distribution of heavy non-aqueous fluid (DNAPL) in underground media is affected by many factors, including the physical and chemical properties of DNAPL, leakage rate, groundwater flow rate and medium heterogeneity. In this paper, we use geostatistical method to generate permeability random field to characterize heterogeneity, and use T2VOC to simulate DNAPL distribution in homogeneous / heterogeneous media with different flow velocities to evaluate the effect of groundwater flow rate and heterogeneity on DNAPL transport Effect of migration. The results show that the increase of groundwater velocity significantly promoted horizontal and vertical DNAPL migration. Under the same flow rate, the enhancement of heterogeneity enhanced the spatial variability of DNAPL pollution plume distribution and transport path, and obvious accumulation and flow around. When the direction of the dominant channel of DNAPL migration is opposite to the direction of the flow velocity, the promotion effect of water flow on DNAPL horizontal migration will be weakened, on the contrary, its promotion effect is enhanced. With the simultaneous enhancement of velocity and heterogeneity, the spreading range of pollution plumes in the horizontal direction increases. In addition, the horizontal and vertical centroid positions (first moment) and the distribution range (second moment) Spatial variability of location and length increases.