Groundwater vulnerability and contamination risk assessment of the Weining Plain, using a modified DRASTIC model and quantized pollution loading method

Abstract

Groundwater resources have become more vulnerable to contamination due to rapid population growth and economic development. This study aimed to assess the groundwater contamination risk in the Weining Plain, China. Based on the specific conditions of the Weining Plain, a new model DRTSWI with a weighting scheme determined by analytic hierarchy process was developed to evaluate the intrinsic groundwater vulnerability for the study area. An integrated approach, combining the toxicity, the release possibility, and the potential release quantity of the pollutants, was used to estimate the pollution loading. The groundwater contamination risk results were obtained by overlaying the intrinsic vulnerability and pollution loading maps. These indicated that two industrial parks pose the main threat to groundwater quality, due to their unfavorable hydrogeological setting and potential pollution sources on the surface. Some areas in and around the industrial parks exhibit groundwater pollution, which was identified on the contamination risk map using buffer analysis. High risk areas are industries with high or medium vulnerability. The vulnerability and contamination risk maps developed for this study are valuable tools for environmental planning and can be used for predictive management of groundwater resources.