三门峡水库蓄清排浑控制运用对库区及下游河道冲淤的影响

Effects on Sedimentation and Degradation of the Reservoir and Its Downstream under the Regulation of Sanmenxia Reservoir

1973年后三门峡水库进入蓄清排浑控制运用时期．1986年以来，进入三门峡水库的水沙量发生了明显的变化，不仅年入库总水沙量有大幅度减少．而且水沙量在年内的分配也变化很大．主要原因不是流域降雨的影响，而是上中游工农业用水量增加和龙羊峡、刘家峡等大型水库调蓄的结果．这些变化对保持库区冲淤年平衡十分不利，下游河道的冲淤也直接受入库水沙量的影响．分析结果表明，三门峡水电站汛期发电是必要的和可行的，应扩大装机容量，并建议打开#11、#12底扎，在大坝左岸再增建一条隧洞，以提高其综合效益．

In resent years the inflow and sediment load of Sanmenxia Reservoir have been changed, and this has resulted in great influence 0n the sedimentation and .degradation of the reservoir and its downstream. In this paper, the reason of the changes and aggradation and degradation of the reservoir and its downsteam are analyzed. Some recommendations on how to increase the benefit of the reservoir are presented.