FEFLOW在黄河下游断流对地下水影响评价中的应用

Application of FEFLOW in Impact of Yellow River Cutoff on Groundwater

结合黄河下游断流对地下水影响评价的研究,利用FEFLOW软件建立了研究区的三维地下水流模拟模型。在此基础上,根据不同断流条件,用模型模拟了黄河侧渗补给量和地下水流场的变化。结果表明,断流对黄河侧渗补给量影响显著:花园口—河口断流300 d,黄河侧渗量减少53.8%;夹河滩—河口全年断流,黄河侧渗量减少75.2%,断流300 d,黄河侧渗量减少46.3%;泺口—河口全年断流,黄河侧渗量减少25.1%,断流300d,黄河侧渗量减少19.8%;利津—河口全年断流,黄河侧渗量减少4.7%。地下水流场的形态和系统边界的水力性质基本没有改变;断流期地下水位下降,在丰水期水位得以恢复,说明该区含水层具有良好的调蓄能力,只要断流时间不长,可保持黄河不傍河水源地的稳定开采。

Combining with the study about the impact of Yellow River cutoff on groundwater, FEFLOW is adopted to set up the groundwater numerical model of the area. Based on the results, the lateral seepage quantity and the groundwater cycle condition is predicted by FEFLOW. The paper analyses the effect of Yellow River cutoff on groundwater： The lateral seepage quantity will decrease 53.8% on condition that the flow cutoff stage from Huayuankou to river entrance and breaking time is 300 days. The lateral seepage quantity will decrease 46.3 % if flow cutoff from Jiahetan to river entrance and breaking time were 300 days,and it will decrease 75. 2% if flow cutoff throughout the year. The lateral seepage quantity will decrease 19.8% if flow cutoff from Luokou to river entrance and breaking time were 300 days,and it will decrease 25.1% if flow cutoff throughout the year. The lateral seepage quantity will decrease 4.7% if flow cutoff from Lijin to river entrance and flow cutoff throughout the year. there are large effect on the lateral seepage quantity and groundwater table, but little effect on the shape of the flow field . The cut-off of Yellow River has a crucial impact on dynamic level of groundwater. However, the large storage capacity of groundwater in the Yellow River affected zone can recover the table in high flow period , therefore, river downstream cut-off will not have a significant impact on groundwater resources of the Yellow River if only the time of cutoff is not too long.