基于GIS技术与DRASTIC模型的民勤盆地地下水脆弱性评价

摘要

Based on the evaluation of groundwater resources in the study area,its geological and hydrogeological conditions were systematically analyzed,the 7 factors affecting the groundwater vulnerability mostly were selected,and the vulnerability assessment model of groundwater vulnerability in DRASTIC was established.On the basis of the analysis of the factors carried out by using the GIS technology,the results on the groundwater vulnerability assessment were obtained,which showed that the groundwater vulnerability there was generally high,because of the shallow groundwater level,the medium of the aquifer being good and no thick layer of cohesive soil being distributed in the aeration zone,thus easy to suffer from the pollution from agricultural planting,domestic sewage and industrial sewage leakage.%在研究区地下水资源评价的基础上,系统分析了其地质与水文地质条件,选取了对研究区地下水脆弱性影响最主要的7个因子,建立了DRASTIC地下水脆弱性评价模型.在利用GIS技术对各因子进行分级分析的基础上,对各因子分析结果进行加权叠加分析,得到了地下水脆弱性评价结果.结果表明:受地下水位埋深较浅、含水层介质较好、包气带中无厚层黏性土分布等的影响,地下水脆弱性总体较高,易遭受农业种植、生活污水及工业生产污水渗漏的污染.