Assessment Methods of Groundwater Antipollution Capability in Typical Karst Regions of Southwestern China

Compared with the Quaternary aquifer,the karst aquifer has a lower antipollution capability in the karst regions of southwestern China due to the absence of the natural impermeable filter layer in these regions,and therefore the surface water and contaminants can easily enter into the karst aquifer or underground river through the sinkhole or other karst features.In this paper,a typical karst region,Guilin karst area,is selected and this region is divided into seven sub-regions according to different geomorphology.The is used to assess the groundwater antipollution capability in the sub-regions of Guilin karst area based on the fact that the karst water has a characteristic of dual supply.The results show that although the proluvial fan sub-region has a strong groundwater antipollution capability in Guilin karst area,other sub-regions have weak groundwater antipollution capability in the karst aquifer,especially in the peak cluster depression and peak cluster valley sub-regions with numerous developed sinkholes,where groundwater can easily be contaminated without any protection.Compared to the previous studies,the method in this study takes into account the runoff as an important evaluation index,which provides more reasonable results.Also,the method requires less data and evaluates the groundwater antipollution capability qualitatively,and thus it can be promoted in the karst regions of southwestern China.