水电站生态流量中的河道地下水补给需水计算

Calculation of Instream Groundwater Recharge Demands in Ecological Flow of Hydropower Projects

大坝建设拦断河流,可能造成下游减脱水,减脱水河道内要产生地表径流,首先应满足河道地下径流的补给需水要求。即首先将河道地下孔隙充满,地下水位抬升至河道表面,而地下水处于流动状态,是一个动态平衡过程。就NB/T 35091—2016《水电工程生态流量计算规范》中河道地下水补给需水计算部分,建立了一套河道地下水补给需水定量计算流程和方法,以马马崖一级水电站为例,进行了试算,可作为相关计算和研究的一个参考和借鉴。

The construction of dam will cut off river flows, which may cause flow reduction in downstream. As a result, the instream groundwater recharge needs to be met at first if the surface runoff needs to be produced in river channel. That is to say, the underground pores under yiverbed should firstly be filled with water and then the underground water table will be uplifted to riverbed surface, and at the same time, the groundwater is in a state of flowing, which is a dynamic balance process. According to the terms of NB/T 35091--2016 ＂Code for Calculation of Ecological Flow of Hydropower Projects＂, a set of quantitative calculation processes and methods are established for the calculation of instream groundwater recharge demands. Taking Mamaya I Hydropower Station as study case, the instream groundwater recharge demand is calculated by using above processes and methods. The conclusions can be used as references in relative calculations and researches in future.