青铜峡水库排沙对下游河道冲淤的影响

Influence of Desilting of Qingtongxia Reservoir to the Channel Scour and Fill of the Lower Reaches

统计了青铜峡水库汛期排沙和汛末拉沙期间下游各河段的淤积状况,通过建立水库下游河道排沙比与进入河道的水沙条件的定量关系,分析有无青铜峡水库时相应时期水库下游河道的冲淤状况。结果表明:由于水库汛期排沙对水沙条件的改变是有限的,因此水库汛期运用未对其下游河道造成增淤;汛末拉沙对下游河道造成了增淤,该期间若不排沙,则同期下游河段将发生微冲。

This study counted the deposition condition of each section downstream Qingtongxia Reservoir during desilting in flood season and scouring in the end of flood season of the reservoir and analyzed and calculated the channel scour and fill conditions of the lower sections of the reservoir in cor-responding period under the conditions of without the reservoir through establishing quantitative relationship of sediment delivery rate of the channel downstream the reservoir and silt-discharge conditions of incoming into the channel. The outcomes show that becouse the change of the reservoir sedi-ment to the incoming water and sediment condition is limited,so the reservoir operation does not cause increasing deposition in the downstream chan-nel;but the deposits flushing by drawdown does,so if there is no sediment discharge in the period,there will be slight scouring in the reach.