黄河下游高村—艾山河段冲刷效率变化研究

Study on Variations of Scouring Efficiency of Gaocun-Aishan Reach on the Lower Yellow River

利用混合挟沙力和不平衡输沙公式,对黄河下游高村—艾山河段冲刷效率的变化进行了分析。结果表明:小浪底水库投入运用以来,高村—艾山河段及其上、下游河段的床沙均发生粗化,一方面使得水流的输沙能力降低,从而降低了冲刷效率;另一方面使进入该河段的含沙量减小,这将有利于该河段的冲刷,提高冲刷效率;随着冲刷历时的延长,高村—艾山河段的冲刷效率虽有所降低,但降低幅度较小。

The paper analyzes the variations of scouring efficiency of Gaocun-Aishan reach of the lower Yellow River by using the formula of mixed sediment carrying force and unbalanced sediment transport.The outcomes show that a) the bedload of Gaocun-Aishan reach and the sections at its upper and lower reaches has coarsened since the Xiaolangdi Reservoir putting into operation.On the one hand,it has reduced the sediment carrying capacity of flow and reduced scouring efficiency;b) on the other hand,it also has reduced sediment concentration of the flow entering into the section,which is favorable to scouring of the section and increasing scouring efficiency and;c) along with the extension of scouring duration,the scouring efficiency of Gaocun-Aishan reach has somewhat reduced but the reduction range is smaller.