小浪底水库拦沙期下游游荡性河段演变趋势研究

通过物理模型试验并结合数学模型计算分析，研究了小浪底水库拦沙期下游游荡性河段的河床演变问题。主要结果表明：（１）小浪底水库拦沙期下游河段自上而下将出现没程度的冲刷，受工程控制较好的河段，河床冲刷以下切为主，而控制较差的河段，河床下切的同时伴随着展宽，塌滩严重。（２）河床冲刷后使河道排泄能力加大，对河床变化过程的影响显著，河床综合稳定性增大，但河型并未转化，（３）游荡性河段冲刷期经常出现水流集中持续

Study of Evolution Trend of Wandering Channel in the Lower Yellow River During Sediment Storage Period of Xiaolangdi Reservoir

The issue of wandering river bed evolution in the lower Yellow River during sediment storage period of Xiaolangdi reservoir is studied through analysis by combination of physical model test and mathematic model calculation. Themain results show that: (1)there will be scour in various scales in all the lower reach during the Period with culting-down scour mainly in the reach of great project protection otherwise cutting-down scour accompanying lateral erosion and severe sloughing bank; (2)flood release capacity of the river will be enlarged by bed scour and resultingin increase of river bed comprehensive stability which evidently impact on river bed evolution process without changein river pattern; (3) there will be frequent danger of concentration flow rushing to dam and banks in wandering riverscouring period.