洪水冲刷增大高村—艾山段平滩流量研究

Study on Bankfull Discharge of Gaocun-Aishan Reach Increased by Flood Scour

研究了小浪底水库运用以来黄河下游各河段糙率变化情况和冲刷强度的变化趋势。结果表明:①小浪底水库运用以来,夹河滩以下河段的糙率没因床沙粗化而增大;②小浪底水库运用以来泥沙粗化对冲刷的影响仅发展到花园口—夹河滩之间,高村—艾山河段冲刷强度没有明显减弱;③在目前河道边界条件下,只要小浪底水库下泄流量大于1 500m3/s,高村—艾山河段即可发生冲刷;④要想使高村—艾山河段平滩流量由3 810 m3/s增大至4 000 m3/s,需要小浪底水库下泄流量大于4 000 m3/s的水量约35亿m3。

The paper studies the roughness variation and variation trend of erosion intensity of each section of the lower Yellow River since the operation of Xiaolangdi Reservoir.The outcomes show that a) the roughness of the section downstream Jiahetan is not increased because of coarser bed material since the operation of Xiaolangdi Reservoir;b) the influence of sediment getting coarser to the scour only develops to the reach of Huayuankou-Jiahetan,the scour intensity of the reach of Gaocun-Aishan is not weakened remarkably since the operation of the reservoir;c) as long as the reservoir discharge is greater than 1 500 m3/s,the reach of Gaocun-Aishan will be scoured under the current boundary condition of the channel;d) if the bankfull discharge of the reach of Gaocun-Aishan is increased from 3 810 m3/s to 4 000 m3/s,it requires about 3.5 billion m3 of water with the reservoir discharge greater than 4 000 m3/s.