Groundwater vulnerability assessment of confined aquifer: case study Jining, China

摘要

The assessment and mapping of the groundwater vulnerability to contamination are of primary importance for hydrogeological studies. Currently, many shallow aquifers around urban areas in China are seriously polluted and can not be drunk or used any more. Therefore, the confined aquifer groundwater exploitation is steadily increasing. When the confined aquifer water level is lower than that of the shallow aquifer, the polluted shallow groundwater will recharge the confined aquifer through the aquitard, which could lead to the pollution of confined aquifer. For most groundwater vulnerability assessment models are developed for shallow aquifer only, it is necessary to develop vulnerability assessment method for confined aquifer, which is the purpose of this study. Our model is developed based on the theoretical analysis of the confined aquifer pollution processes, and the artificial neural network is used to obtain the weights for assessment factors. Also, The GIS overlay technology is adopted to generate the confined aquifer groundwater vulnerability map. This study is carried out in Jining city, and the assessment results are reasonably consistent with the change of total hardness concentration.