College of Water Sciences, Beijing Normal University, Beijing 100875, China.
State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
Sci Rep. 2017 Apr 7;7:45955. doi: 10.1038/srep45955.
The characteristics of vadose zone vulnerability dominating factors (VDFs) are closely related to the migration and transformation mechanisms of contaminants in the vadose zone, which directly affect the state of the contaminants percolating to the groundwater. This study analyzes the hydrogeological profile of the pore water regions in the vadose zone, and conceptualizes the vadose zone as single lithologic, double lithologic, or multi lithologic. To accurately determine how the location of the pollution source influences the groundwater, we classify the permeabilities (thicknesses) of different media into clay-layer and non-clay-layer permeabilities (thicknesses), and introduce the maximum pollution thickness. Meanwhile, the physicochemical reactions of the contaminants in the vadose zone are represented by the soil adsorption and soil degradability. The VDFs are determined from the factors and parameters in groundwater vulnerability assessment. The VDFs are identified and sequenced in simulations and a sensitivity analysis. When applied to three polluted sites in China, the method improved the weighting of factors in groundwater vulnerability assessment, and increased the reliability of predicting groundwater vulnerability to contaminants.
包气带脆弱性主控因子（VDFs）的特征与包气带中污染物的迁移转化机制密切相关，直接影响污染物向下渗滤到地下水的状态。本研究分析了包气带孔隙水区域的水文地质剖面，并将包气带概念化为单一岩性、双重岩性或多重岩性。为了准确确定污染源的位置如何影响地下水，我们将不同介质的渗透率（厚度）划分为粘土层和非粘土层渗透率（厚度），并引入最大污染厚度。同时，包气带中污染物的物理化学反应由土壤吸附和土壤降解性来表示。VDFs 是从地下水脆弱性评估中的因素和参数中确定的。在模拟和敏感性分析中识别和排序 VDFs。当应用于中国的三个污染场地时，该方法改进了地下水脆弱性评估中因素的权重，提高了预测污染物对地下水脆弱性的可靠性。
