岷江上游水电开发对河道减脱水的影响研究

Impact of hydropower development in upper reaches of Minjiang River on flow reducing of river reaches

通过对岷江上游水电站以及受影响河道的实地调查,建立了河道减脱水评价指标,分别对岷江干流、一级支流及二级支流河道的减脱水情况进行了分析。在对减脱水河道分析的基础上,分析了调查断面距电站坝址的距离、电站类型、电站装机容量、电站调节性能与河道减脱水的关系。结果表明:水电开发引起河道减脱水现象已非常严重,各级支流上游都有不同程度的断流现象,以二级支流最为严重;河道减脱水严重程度随距电站坝址的距离增加呈减小的趋势;电站的类型、调节性能与河道减脱水存在明显的相关性,而装机容量对河道减脱水的影响不大。在制定流域水电开发以及河流生态系统恢复规划时,应考虑电站类型、调节性能对河道减脱水的影响。

Based on the field investigation of hydropower stations in the upper reaches of the Minjiang river and the affected reaches,we established a evaluation indicator system of the flow reducing reaches（or dried reaches）,and analyzed the flow reducing（or dried） conditions of the mainstream,first tributary and second tributary of the river. According to analysis results,we discussed the relationship of the flow reducing（or dried） condition and the distance from the investigation section to the dam site,power station type,installation capacity and adjustment ability. The results show that the flow reducing reaches（or dried reaches） caused by the hydropower development is very serious in this region; discontinuous flow phenomenon of different degrees appear at all levels of the upstream tributaries,especially in the secondary tributary; and the reducing reaches（or dried reaches）is less serious as the distance from the dam site increases; the type and regulation performance of power stations are obviously related with the flow reducing reach（or dried reach）,but the installed capacity has no influences. So it is necessary to take account of the impacts of power station＇s type and regulation performance when formulating a basin hydropower development and river ecological recovery plan.