人类活动影响下北京市平原区地下水资源变化研究

Study on the Change of Groundwater Resources in the Plain Area of Beijing under the Influence of Human Activities

地下水开采是为人类的工农业发展和居民生活服务的,是人类利用、影响地下水资源最直接、最重要的方式。为研究地下水压采和远程回灌等人类活动对北京市平原区地下水利用的影响,在校准的三维非稳定流GMS模型的基础上设计了4种情景(保持现状的情景S1、沉降中心地下水压采50%的情景S2、沉降中心地下水采用不同压采比例的情景S3和潮白河冲洪积扇顶部远程回灌的情景S4)进行预测与分析。结果表明:(1)对于区域地下水水位,情景S1和S4下分别平均下降0.223 m/年和0.048 m/年,而情景S2和S3下分别平均恢复0.310 m/年和0.658 m/年;(2)平均来看,在情景S1和S4下每年分别消耗1.04×10^(8)m^(3)和0.25×10^(8)m^(3)的含水层储量,而在情景S2和S3下则每年分别恢复1.30×10^(8)m^(3)和2.95×10^(8)m^(3)的含水层储量;(3)地下水压采和远程回灌等人类活动可以有效恢复地下水水位与含水层现状储量,是北京市解决地下水超采及地面沉降等问题的有效方法。地下水压采量越多,对于地下水水位和含水层现状储量的恢复效果越好。

The groundwater exploitation serves the industrial and agricultural development and resident life and is the most direct and important way for human to use and influence groundwater resources.In order to study the impact of human ac-tivities such as groundwater withdrawal reduction and remote reinjection on the groundwater utilization in the plain area of Beijing,four scenarios(scenario S1 of maintaining the status quo,scenario S2 of 50%groundwater withdrawal reduction in the subsidized centers,scenario S3 of different proportions of groundwater withdrawal reduction in the subsidized centers,and scenario S4 of remote reinjection at the top of the alluvial proluvial fan in the Chaobai River)were designed,predicted and analyzed based on the calibrated three-dimensional unsteady flow GMS model.The results show that:①the regional groundwater level,respectively decrease by 0.223 m and 0.048 m per year in the situation of scenarios S1 and S4,while respectively recover by 0.310 m and 0.658 m per year in the situation of scenarios S2 and S3;②on average,scenarios S1 and S4 consume 1.04×10^(8)m^(3) and 0.25×10^(8)m^(3) groundwater each year,respectively,while scenarios S2 and S3 recover 1.30×10^(8)m^(3) and 2.95×10^(8)m^(3) groundwater each year,respectively;③the human activities such as groundwater withdraw-al reduction and remote reinjection can effectively restore the groundwater level and current aquifer storage,which is an effective method to solve the problems of groundwater overexploitation and land subsidence in Beijing.The more groundwa-ter withdrawal reduced,the better the recovery effect of groundwater level and current aquifer storage.