鄂尔多斯白垩系盆地浅层地下水易污性评价

Evaluation of Vulnerability to Pollution of Groundwater in Ordos Basin of Cretaceous System

[目的]评价鄂尔多斯白垩系盆地浅层地下水的易污性。[方法]针对传统的DRASTIC地下水易污性评价模型中专家打分及赋权重主观性强等局限性,利用过程数学模拟、GIS空间分析和主成分分析对其进行改进,并将改进模型应用于鄂尔多斯白垩系盆地北区浅层地下水易污性评价。同时,分析了研究区浅层地下水易污性强度及其形成原因,并对该地区地下水保护提出了建议。[结果]采用改进的DRASTIC方法评价鄂尔多斯白垩系盆地北区浅层地下水的易污性,评价结果客观、可信;农药化肥的使用是鄂尔多斯白垩系盆地北区浅层地下水易污性强的最主要的影响因子,建议居民尽量较少农药、化肥的使用;包气带厚度、岩性、蒸发作用等水文地质因素导致低洼的湖泊地区地下水易污性较强,建议居民在开采饮用水时尽量远离湖泊,或开采较深层的地下水。[结论]该研究为区域浅层地下水易污性的评价提供了新方法。

[ Objective ] The aim was to evaluate the vulnerability to pollution of groundwater in Ordos Basin of cretaceous system. [Method] Mathematical modeling, GIS spatial analysis and multivariate statistical analysis technologies were introduced to improve the traditional groundwater vulnerability assessment model of DRASTIC in view of its strong subjective for expert estimation and weight assigning. In the meantime,the intensity and reasons of vulnerability to pollution of groundwater in the area were studied, and measures to protect local groundwater were proposed. [ Result] Using improved DRASTIC method to assess the vulnerability to pollution of groundwater in Ordos Basin of cretaceous sys- tem was objectively and reliable. The application of fertilizer was the main influential factors to the vulnerability to pollution of groundwater in Ordos Basin of cretaceous system. It was advised to lessen the usage of fertilizer and not to drink water from lake or deep ground water. Density, rock, and evaporation were factors that led to intensive vulnerability to pollution of groundwater in shallow areas. [ Conclusion] The study provided a new method for the evaluation of vulnerability to pollution of groundwater in Ordos Basin.