Current status and evaluation of groundwater resources exploitation in the plain area of Beijing

The current status of groundwater resources exploitation in the plain area of Beijing is analyzed in this paper, and problems caused with the development of groundwater are also discussed. Based on an analysis of the local hydrogeological conditions, a corresponding numerical simulation model is built with FEFLOW. After identification and verification of the model, the evaluation of groundwater resources is carried out. The reseach results indicate that calculation of groundwater balance from 2000 to 2003 are -7.73, -6.02, -5.95 and -4.38×108 m~3, respectively. The main recharges of groundwater include infiltration from precipitation and subsurface runoff from the mountainous areas, and the main form of discharge is groundwater exploitation. The annual average recharge of groundwater is 24.13×108 m~3. Potential groundwater resources for exploitation exist in the area of Pinggu and Changping, whereas groundwater in the Mihuaishun plain has been overexploited. Groundwater quality in the piedmont counties is fine, whereas groundwater quality in some areas in the outskirt of Beijing, such as Daxing, Fangshan and Tongzhou, is relatively poor. The main causes resulting in groundwater contamination are discussed in the final part of the article.