城区河道蓄水对地下水影响的数值模拟

Numerical Simulation of the Effect of Urban Channel Water Storage on Groundwater

采用MODFLOW软件模拟了汾河太原段河道蓄水工程对地下水的影响,预测了蓄水池四周无防渗处理,防渗墙渗透系数为10-5、10-6cm/s的封闭式防渗处理,悬挂式防渗处理4种工况条件下的年渗漏量、最大水位壅高值、回水影响宽度。结果表明:不做防渗处理时,年渗漏量很大,水位壅高值也很大,汾河河道蓄水将引起汾河东岸3 km范围内地下水位抬升,会使蓄水池附近大部分地区受浸没影响;封闭式防渗墙可以有效降低水位壅高值,减小城区受浸没影响的范围,而悬挂式防渗处理的效果远低于封闭式防渗处理。

MODFLOW software was applied to simulate the river channel water storage project impact on groundwater in the section of Taiyuan of Fen River. Forecast annual seepage quantity, water table increase and area which would be immerged, under four kinds of working conditions which were no imperious wall, hanging-style imperious wall, and closure-style imperious wall with permeability coefficient 10^-5, 10^-6 cm/s respectively. The results show that in the condition of no imperious wall, annual seepage quantity and water table increase are great ; channel water storage will cause the increase of water table in 3 km length from the east bank of Fen River, most of the area nearby the channel water storage will be affected by the immersion tank. Closure-style imperious walls can effectively reduce the rise of water table, and reduce the city＇ s backwater effect width, while the treatment effect of hanging-style imperious wall is far lower than closure-style imperious wall.