Evaluation Methods and Application Examples of Karst Groundwater Resources

Compared with the Quaternary aquifer, in the karst area in Southwest China, there is often a lack of the natural seepage or filtration layer, and the anti fouling ability of the groundwater in the karst aquifer is poor. The surface water and the pollutants can directly run into the aquifer or the underground river easily through the drowning cave and other karst features. Now with a typical karst area - xx area as an example, in according to the general configuration of the earth's surface, the region is divided into seven sub regions. Based on this, combined with the characteristic of the binary recharging of the karst water, the author tries to use the "binary" method to carry out the partitioned evaluation of the anti fouling ability of the groundwater in the karst area in xx city. The evaluation results show that in the xx district, the antifouling ability of the groundwater in the alluvial fan sub area is strong, while the karst underground waters in other parts are facing the problem that the anti fouling ability is poor, especially in the two sub regions of the karst peak cluster depressions and the peak cluster valley. If we do not protect them, the groundwater will be easily contaminated. By comparing with the results of the previous researches, this method can use the runoff characteristic as one of the main evaluation factors, and the results are more reasonable. And the method has the advantages that few data are required and we can carry out the qualitative evaluation, which can be promoted in the karst areas in Southwest China. In China, the total karst area in the karst areas of Southwest China is about 780 thousand km(2). Due to the strong karstification of the region, and because the dissolved pore, the dissolved gap, the karst cave and the underground river systems are well developed, and the surface water is often lost for the groundwater, the underground water is the main part of the water resources in the area. At the same time, there is a lack of the proper groundwater protection zone in the majority of the areas in the southwest karst areas, and the impermeable filter layer is very thin, so that the underground water is easy to be polluted. Therefore, to find a simple and feasible method to evaluate the groundwater vulnerability is the key to protecting the vulnerability of the groundwater in the karst areas.