北京市平谷盆地地下水库调蓄能力模拟研究

Simulation of Groundwater Reservoir Regulation Capability of the Pinggu Basin in Beijing

平谷盆地第四系含水层厚度大．分布较广、蓄水条件好,形成容积巨大的天然地下水库。充分利用其地下水库容积调蓄年际、年内丰枯不均降水量,对保证北京城市稳定供水具有重要的现实意义。本文在综合分析盆地水文地质资料基础上,建立了地下水库数值模拟模型,并对地下水调蓄能力进行了模拟。结果表明,在王都庄和中桥可以建立地下水源地．两个水源地具有开采量20×104m3／d的开采潜力。在两个水源地应急开采3年后,盆地地下水位平均下降12-14m,水源地停止开采后,在其它开采条件不变的情况下,经过1个丰水年加3个平水年其地下水位基本恢复到初始状态。

The Pinggu basin is about 80 km northeast of Beijing City, where Quaternary aquifers are thick and widespread with favorable storage conditions, resulting in a natural groundwater reservoir of huge volume. Making a full use of the groundwater reservoir to regulate the uneven annual or long-term precipitation is of key importance for stable water supply to the city. Based on an integrated analysis of hydrogeological data of the basin, a groundwater numerical model is built, and the self-regulation potential of the groundwater reservoir is also simulated. The results indicate that two groundwater sources can be built at Wangduzhuang and Zhongqiao, with a potential yield of 20 ?10 4m3/d. After three years of emergency exploitation during the arid season, the average water table of the aquifers dropped about 12 to 14 m. When the exploitation of the water sources ceased, and other conditions were unchanged, the water table recovered after one wet year and three normal years.