Responses of groundwater vulnerability to groundwater extraction reduction in the Hun River Basin, northeastern China

Abstract

ABSTRACTIntensive groundwater extraction causes many environmental problems globally. Reducing groundwater extraction is a primary method for alleviating these problems. However, this reduction may create new pollution issues because of an increase in groundwater vulnerability. A case study was done using the DRAOTIC evaluation method (an improved DRASTIC method for organic pollutant in aquifer vulnerability; soil (S factor) has been updated by organic matter (O factor) in the method) for the Hun River Basin, northeastern China, where groundwater intensive extraction had caused serious environmental and hydrogeological problems. The assessment results show that moderate vulnerability level is the main vulnerability level in the Hun River Basin; high vulnerability level and low vulnerability level categories occupy a smaller area; while very high and very low vulnerability categories occupy the smallest area. By combining the predicted groundwater level distribution and DRAOTIC model, the responses of groundwater vulnerability to different groundwater extraction reductions could be studied. The results show that groundwater vulnerability levels increased as groundwater extraction was reduced; this is because the rising groundwater levels make it easier for pollution coming from the surface to reach the aquifer. The more the reduction in groundwater extraction, the greater the increase in the area with higher vulnerability levels, and the greater the increase in pollution risk.