摘要
为研究单井抽出-回渗同步循环地下水水力控制技术中主要参数之间的关系以及参数对该技术的影响,搭建实验室尺度孔隙含水层物理砂柱模型并基于该物理模型构建MODFLOW地下水流数值模型,研究了通过单井抽出-回渗同步循环过程来实现人工控制地下水流场和水力梯度的可行性以及水文地质条件和水动力条件的影响.结果表明:(1)物理装置运行一段时间后,抽出-回渗达到平衡.(2)基于物理装置不同位置实测水位校准后的数值模型精度较为理想(纳什效率系数为0.88),可以较好地刻画实现水力控制时物理模型中的实际地下水流场.(3)抽出-回渗量的变化对水位降落漏斗的范围(28.0~28.5 cm)几乎无影响,而对其降深影响较大,当抽出-回渗量分别为1、2.5、5、10 cm3/s时,最大降深分别达到1.76、4.55、9.75、18.65 cm,分别为含水层厚度的2.5%、6.5%、13.9%、26.6%.(4)基于裘布依公式,实现水力控制时含水层不同位置处水位高低与抽出-回渗量大小(水动力条件)和含水层渗透性强弱(水文地质条件)有关,根据16种抽出-回渗和含水层渗透性的不同情景的数值模拟结果拟合,发现Q/K与(h2-hw2)/(lgr-lgrw)(h为含水层某处水位,m;hw为抽水井处水位,m;r为含水层某处与抽水井井轴距离,m;rw为抽水井半径,m)之间呈线性关系,拟合系数R2=0.99.研究显示,结合物理和数值模型,采用裘布依公式获取水力控制必要参数和对应关系,为实际场地的应用提供理论参考.
In order to reveal the relationship between the main parameters in the single-well pump-out-infiltration synchronous circulation groundwater hydraulic control technology and the influence of these parameters on its performance, a physical model of the laboratoryscale sand column pore aquifer was constructed, and on this basis a numerical model of MODFLOW groundwater flow was built. The feasibility of artificially controlling the groundwater flow field and hydraulic gradient through the single-well pump-out-infiltration synchronous circulation process and the influence of hydrogeological and hydrodynamic conditions were investigated. The results show that:(1) The pumping-return seepage reaches equilibrium after a period of operation.(2) The accuracy of the numerical model based on the calibration of the measured water level at different locations of the physical device is more satisfactory(Nash-Sutcliffe efficiency coefficient is 0.88), which can better describe the actual groundwater flow field in the physical model when realizing hydraulic control.(3) The variation in the extraction-return seepage volume has almost no effect on the range of the water level landing funnel(28.0-28.5cm), while it addressed a greater effect on its depth of descent, when the extraction-return seepage volume is 1, 2.5, 5, and 10 cm~3/s. The maximum depth of descent reaches 1.76, 4.55, 9.75 and 18.65 cm, which are 2.5%, 6.5%, 13.9% and 26.6% of the aquifer thickness,respectively.(4) Based on the Dupuit formula, the water level at different locations in the aquifer during the realization of hydraulic control is related to the magnitude of pumping-out-return seepage(hydrodynamic conditions) and the strength of aquifer permeability(hydrogeological conditions). Based on the fitting results of numerical simulation of 16 different scenarios of pumping-out-return seepage and aquifer permeability, a linear relationship between Q/K and(h~2-hw~2)/(lgr-lgrw) was obtained(h represents the water level at a location in the aquifer, m;hwrelates to the water level at the pumping well, m;r is the distance between a location in the aquifer and the pumping well shaft, m;rwis the radius of the pumping well, m), and the fitting coefficient R~2 reached 0.99. With the combination of physical and numerical models, the required parameters and corresponding relationship for hydraulic control were obtained by using the Dupuit equation, providing a theoretical reference for field application.
作者
王新港
杨昱
徐祥健
韩旭
夏甫
邓圣
肖瀚
姜永海
WANG Xingang;YANG Yu;XU Xiangjian;HAN Xu;XIA Fu;DENG Sheng;XIAO Han;JIANG Yonghai(State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;School of Energy and Environmental Engineering,Hebei University of Engineering,Handan 056038,China)
出处
《环境科学研究》
CAS
CSCD
北大核心
2023年第1期180-187,共8页
Research of Environmental Sciences
基金
国家重点研发计划项目(No.2019YFC1806200)。
关键词
抽出-回渗同步循环
水力控制
砂柱物理模型
数值模型
pumping-recharge synchronous circulation
groundwater hydraulic control technique
sand cylinder physical model
numerical model
