黄藏寺水利枢纽对张掖盆地地下水影响研究

Influence of Huangzangsi Water Control Project on Groundwater Environment in Zhangye Basin

黄藏寺水利枢纽工程建成运行后,将在输水关键期采用大流量输水并废除部分平原水库或其灌溉功能,地下水补给的减少或将对黑河中游张掖盆地地下水环境产生影响。由于黑河中游张掖盆地地表水与地下水存在密切联系,单独采用地下水数值模型难以准确描述地表水与地下水的转化关系,因此采用MIKE-SHE软件建立了黑河中游盆地的地表水—地下水耦合数值模型,通过校正后的模型对工程运行后的地下水演变进行了预测。模拟结果表明:黄藏寺水利枢纽工程运行对黑河中游张掖盆地地下水影响有限,河道与水库渗漏减小引起的地下水位下降值远小于当地地下水位天然变幅,可由地下水系统自然调节。

Huangzangsi Water Control Project is planning to use a larger flow rate to transport water and to shut down some reservoirs in the basin. The decrease of groundwater recharge due to this new project will affect the groundwater environment in the middle reaches of Heihe River,i.e. the Zhangye Basin. Because of the close relationship between surface water and groundwater in Zhangye basin, it is difficult to de-scribe the interaction between surface water and groundwater by a groundwater numerical model. Therefore,based on the MIKE-SHE soft- ware, a coupled surface-water and ground-water numerical model was established in Zhangye basin. Base on the calibrated model, the groundwater flow during future project operations was simulated. The simulation results show that the drawdown of groundwater caused by the decrease of leakage from the river and resen,oirs is much smaller compared with local groundwater table fluctuation. Thus, the small change in groundwater level can be naturally adjusted by the local groundwater system. Therefore, the environmental effect of groundwater in Zhangye basin is limited according to the simulation results.