岩溶地下水脆弱性评价是基于保护岩溶含水层从而有效地管理和利用地下水提出的有效方法和手段。我国西南岩溶区极大多数地区缺少应有的地下水保护带,地下水比较容易受到污染。本文论述了一种脆弱性的评价的简单方法——基于径流特征和覆盖层厚度的二元法,并利用该法对重庆金佛山典型岩溶区进行了地下水脆弱性评价。结果表明,药池坝洼地和生态石林区脆弱性较高。究其原因,尽管药池坝洼地底部土壤层覆盖较厚,但存在地表径流集中排向落水洞,生态石林分布区地表裂隙、溶沟发育,可直接接受雨水入渗,因而污染物极易通过降雨和地表径流过程进入含水层。这一方法输入数据量小,对岩溶含水层普遍适用,为地下水资源可持续利用和土地利用管理提供了强有力的工具。
Assessment of karst groundwater vulnerability is a valid method that is put forth on the basis of protecting karst groundwater aquifer, in order to manage and use groundwater effectively. Groundwater lacks protective zone that should have had in most karst area in Southwest China, so the groundwater is easy to be polluted. A large number of methods of vulnerability assessment have been proposed for the protection of carbonate (karst) aquifers. In this paper, the authors discussed a simplified method--Duality method for karst groundwater vulnerability assessment on the basis of two factors: the overlying layers (O) and the concentration of flow (C), and the application of the methodology in Jinfo mountain of Chongqing, a subtropical karst mountain area, is presented. The results showed that Yaochiba depression and eco-Shilin (stone forest) area present “very high” and “high” vulnerability respectively. Contaminants can easily enter the subsurface through thin soil cover in stone forest and via swallow holes at the bottom of depression. The method requires only a minimum of data and can be applied to all types of aquifers. The resulting maps could be used as valuable tools for sustainable groundwater-land use management. Up to now, protective zones for groundwater are often absent in Southwest China karst area, and many subterranean streams and karst springs have contamination problem that mainly resulted from agricultural activities and untreated domestic wastewaters. The implementation of protection schemes could help to improve the situation,