Groundwater vulnerability assessment of North China Plain

Abstract：In the light of the characteristics of North China plain such as vast area, complex landform and hydrogeological conditions, high degree of groundwater exploitation, remarkable differences in buried depth of groundwater, aerated zone and aquifer lithology and on the basis of large quantities of drilling and groundwater level monitoring data, the authors redefined the influence of changes of aerated zone lithology and groundwater level depth on the groundwater vulnerability assessment, and established the DRITC evaluating indicator system suitable for North China plain and applied it to groundwater vulnerability evaluation. According to the hydrogeological conditions, the North China plain was divided into 4 appraisal districts and 34253 units of 2×2 km2. Groundwater level depth, net recharge, aerated zone lithology, aquifer accumulated thickness and hydraulic conductivity were taken as evaluation indexes, and then groundwater vulnerability composite index and distribution map were obtained. The results indicate that the groundwater vulnerabilities of piedmont alluvial-proluvial fan and Yellow River affected zone in old Yellow River alluvial-proluvial plain are high or very high. The test results of 7472 groups of groundwater organic pollution samples show that detected number of components is more in high or very high vulnerability areas and less in other areas, which validates the objectivity of the evaluation results.