黄河水沙变化与下游河道治理思考

由于黄河水沙条件的不利变化，黄河下游出现了小水大灾和长期断流，三门峡水库“蓄清排浑”运用经验的局限性表现得更为突出。从黄河下游河道输沙，防洪和水资源充分利用出发，小浪底水库应采取泥沙多年调节的运用方式，枯水，平水年蓄水拦沙运用，丰水年洪水期集中泄空冲刷产生讷和洪水，塑造窄深河槽，改造高村以上宽浅河道，利用窄深河槽输送较高含沙洪水入，，经多方案计算结果比较分析表明上述方案减淤效益显著，并可大量节省输

Changes of Runoff and Sediment Load and Ponders of Training of the Lower Yellow River

Due to the unfavorable changes of the runoff and sediment load, such events as the severe disasters caused by the small floods and long time no flow have come out in the Lower Yellow River. The shortcomings of the operational mode of the Sanmenxia Reservoir, i.e. impounding flow with less sediment in non flood season and discharging flow with much sediment in flood season have been exposed apparently. For the purposes of sediment transportation, flood controlling and development of the water resources in the Lower Yellow River, it is suggested that the multi year regulation of sediment should be applied in the operation of the Xiaolangdi Reservoir. Impounding the incoming flow and sediment load in the years of less water, and releasing them from the reservoir in the flood seasons in the years of rich water, are effected so as to erode the deposits in the reservoir to yield a hyperconcentrated flow that is favorable for the forming of the narrow and deep channel and training the wide and swallow channel above the Gaocun Station. The calculated results of the multi-scheme operation prove it that the way of transporting hyperconcentrated floods into the sea through a narrow and deep channel can save much water for sediment transportation and, hence, can make more reasonable utilization of the water resources of the Yellow River. Besides, it is suggested that the improvement of the broad channel into one consisting of a narrow and deep main channel flanked by broad flood plains should be strengthened in order to prevent the flood plains in the broad channel reach above Gaocun from caving in due to the erosion by the released clear flow from the Xiaolangdi Reservoir.