汾河三期蓄水工程人工湖渗漏对太原市浅层地下水影响的数值模拟

为分析汾河三期工程人工湖渗漏对太原市浅层地下水的影响,建立人工湖与地下水流耦合数值模型,并选取渗透系数、给水度、降水入渗系数、最大蒸发系数和湖底电导率5个影响因素进行正交试验分析。数值模拟结果表明,人工湖不进行防渗处理时,年渗漏量为1 259.6×10~4 m~3,最大壅高值为2.4m,壅高影响距离6.7km,对太原市浅层地下水影响较大,垂直封闭防渗有效地减小了湖泊渗漏量与地下水壅高范围,渗漏量随防渗墙进入潜水隔水层深度的增大而减小。正交试验结果表明,各影响因素对年渗漏率的影响程度从大到小依次为湖底电导率渗透系数最大蒸发系数给水度降水入渗系数。研究成果可为太原市人工湖建设与工程防渗设计提供依据。

Numerical Simulation of Impact of Artificial Lake Leakage on Shallow Groundwater in Taiyuan in Third Stage of Fenhe River Water Storage Project

Taking Fenhe River in Taiyuan City as an object of study, a numerical simulating model about water exchange between artificial lake and groundwater was built to predict the impact of artificial lake on shallow groundwater in Taiyuan City. Sensitivity analysis was performed by the selection of five coefficients which are permeability coefficient, specific yield, infiltration coefficient, maximum evaporation intensity, lake conductivity. The results of numerical simulation show that the annual leakage of artificial lake is 1259.6×104m3, the maximum height of back-water is 2.4 m and the range of bank-up groundwater is 6.7 km leading to obvious rise of regional groundwater level and immersion of partial area. The results of parametric sensitivity analysis show that factors influencing simulation results of numerical model follow a descending order of lake conductivity, permeability coefficient, maximum evaporation intensity, specific yield, infiltration coefficient. The results has a certain guiding significance for the construction of artificial lake and the design of anti-seepage engineering.