基于DRASTIC的丽水市地下水防污性能评价

地下水防污性能反映地下水系统遭受污染的可能性,可以为土地利用规划、地下水资源保护规划、地下水水质监测等提供科学依据。此论文结合丽水市的水文地质条件,对DRASTIC评价模型进行了改善,建立了符合丽水市的DRAMTIC评价模型。该模型由大气降雨入渗补给量、地下水埋深、包气带介质、水力传导系数、含水层厚度、地下水开采强度、地形坡度等7个因子组成,以乡镇单元等为界线划分不规则评价单元,评分体系由单因子区域分布规律确定,采用主成分—因子分析法分析各因子的权重体系;利用差分法对各因子加权叠加的综合指数进行等级划分,应用GIS技术得到丽水市地下水防污性能评价图。该模型的评价结果客观科学,能有效的为规划部门及地下水资源管理部门服务。

Assessment of Groundwater Vulnerability in Lishui City Based on DRASTIC

Groundwater vulnerability reflects the relative possibility of groundwater system to be polluted.The results of groundwater vulnerability research can provide a useful tool for land-use planning,groundwater protection planning and groundwater quality monitoring.Based on the hydrogeological conditions of Lishui City,this paper has established the DRAMTIC evaluation model for Lishui City,by improving the DRASTIC assessment model.The model consists of seven parameters such as recharge of rainfall infiltration,depth of groundwater,impact of the vadose zone media,conductivity,aquifer thickness,mining intensity to groundwater,and topography.The area was divided into irregular evaluation units by the boundaries of the township.The rating system was determined by the regional distribution of regularity of a single factor.The weight system was established by the principal components-factor analysis method.The comprehensive index of weighted superposition on each factor was divided into different ranks using the finite difference method.The above groundwater vulnerability assessment of Lishui City may be obtained by GIS technology.The objective and scientific assessment results of this model can effectively serve for the planning department and manage department of groundwater resource.