北京张坊岩溶地下水库联合调蓄研究

Study on United Regulation-storage of the Zhangfang Karst Groundwater Reservoir in Beijing

北京张坊岩溶地下水库位于北京市房山区,属半开放式山前浅埋岩溶地下水系统,其补给条件好。文章应用多种技术手段,对区域构造应力场、水动力场等进行综合对比分析。研究结果表明,张坊水源地地区是一个相对独立的岩溶地下水库,区内岩溶水的分布明显受构造控制,富水性不均匀。拒马河自西北向东南纵穿整个水源地,为地表水和地下水的联合调蓄创造了条件。区内拒马河平均年径流量在五渡以上为7800×104m3/a,地下水可采资源为2330×104m3/a,年内最大可调蓄库容为4690×104m3/a。张坊应急水源地和拒马河河水具备联合调蓄条件,二者结合可满足年平均供水1~1.2×108m3/a。

The Zhangfang karst groundwater reservoir is located in Fangshan district, Beijing. It is a semiopen shallow buried karst-water system and has good recharge conditions. The regional tectonic stress field and groundwater dynamic field were analyzed by varied methods. The research results show that a relatively independent karst groundwater reservoir has been formed in Zhangfang, where the distribution of karst-water is apparently dominated by geological structure, and the water yield property distributes unevenly. Also, the Juma River, which runs through the Zhangfang karst groundwater reservoir from northwest to southeast, provides good conditions for regulation-storage between surface water and groundwater. The average annual flow of the Juma River above Wudu is 7800×104 m3/a, and the average annual groundwater that can be exploited is 2330×104 m3/a, and the largest regulation-storage capacity is 4690×104 m3/a. Zhangfang emergency water source can be jointed with the Juma River surface water, and can reach annual total water supply of 1×108~1.2×108 m3/a.