沉降中心减采对北京平原地下水利用的影响分析

【目的】研究沉降中心减采对北京平原地下水利用的影响。【方法】采用非稳定流地下水模型和情景分析的方法,通过设计4个情景(现状保持(情景BAU)、沉降中心完全停采(情景PR100)、沉降中心减采50%(情景PR50)及沉降中心不同地区减采不同比例(情景PR520))模拟了地下水减采的影响。【结果】预测期内平均来说,情景BAU消耗1.16亿m3/a的含水层储存量,而情景PR100、PR50和PR520的储存量恢复分别为3.52亿、1.18亿和2.83亿m3/a。设计满足控沉目标的情景R:八仙庄、天竺和王四营用于工业和生活的地下水分别减采0.51亿、0.12亿和1.76亿m3,总开采量19.28亿m3,R是满足地面沉降控制要求条件下北京平原应采取的开采情景。【结论】沉降中心减采能有效恢复北京平原地下水水位和含水层储存量,是解决北京市地下水严重超采及其带来的地面沉降等生态环境问题最直接有效的方法,但要合理确定减采的比例,保证社会经济和地下水的协调发展。

Analyzing the Effect of Reducing Aquifer Pumping from the Subsidized Center on Groundwater Utilization in Beijing Plain

【Objective】The objective of this paper is to study the influence of reducing groundwater pumping from the subsidized center on groundwater utilization in Beijing Plain.【Method】Based on the unsteady groundwater flow model and scenario analysis, four scenarios(BAU, PR100, PR50 and PR520) were designed to simulate the impact of groundwater-pumping reduction from the subsidized center on the groundwater utilization in Beijing plain.【Result】On average for the prediction period, scenario BAU will deplete 116 million m3 aquifer storage per year, while scenarios PR100, PR50 and PR520 will recover 352, 118 and 283 million m3 aquifer storage per year,respectively. An exploitation scenario R, which meets the land subsidence control goal in the future, is designed through the analysis of the above scenarios: pumping reduction amounts in the subsidence centers are 0.051 billion m3/a(100% reduction), 0.012 billion m3/a(20% reduction) and 0.18 billion m3/a(50% reduction) in zones Baxianzhuang, Tianzhu and Wangsiying, respectively. The total pumping amount is 1 928 million m3/a.【Conclusion】Groundwater pumping reduction in the subsidence center can effectively recover the groundwater level and aquifer storage and is the most direct and effective method to solve the serious groundwater overexploitation and related land subsidence in Beijing. However, the proportion of groundwater pumping reduction should be reasonably determined to ensure the coordinated development of social economy and groundwater.