A Comparative Study of Groundwater Pollution Narrow/General Vulnerability in Xi''an
西安市地下水污染广义/狭义脆弱性对比研究

Based on the system of "pollution source drainage-vadose zone transmission-groundwater pollution",this paper has put forward the concept of narrow and general groundwater vulnerability and constructed the evaluation index system and the corresponding method.According to an extensive investigation of hydrogeological conditions and pollution sources,the authors made an analytical test on the groundwater vulnerability by using the GIS technique.Some conclusions have been reached:Concerning the groundwater narrow vulnerability deduced from the hydrogeological conditions,the riverbed,floodplain,first terrace and city center with artificial earth fill are most vulnerable,but they are not consistent with the realistic pollution distribution;as for the general vulnerability of groundwater pollution that takes into account land use and pollution source distribution,the building area and the northern suburb irrigation area are most vulnerable,and these areas agree basically with the distribution of groundwater pollution.It is thus thought that the narrow vulnerability is suitable for extensive areas where the difference of human activity impacts is relatively small,and the general vulnerability fits urban areas where the difference of human activity impacts is fairly obvious,which means that the two methods have their respective reasonably suitable conditions.