黄河上游高含沙水流交汇区河床形态及冲淤变化规律

发布时间：2018-03-01 21:47

本文关键词： 高含沙洪水水流交汇区淤积沙洲河床形态淤积模式　出处：《水力发电学报》2017年12期 　论文类型：期刊论文

【摘要】：黄河上游交汇区为典型的高含沙水流交汇区,支流高含沙洪水往往引起剧烈的河床形态调整及冲淤变化。利用室内模型实验、野外观测资料,研究了支流高含沙洪水入汇干流后,交汇区变化过程及冲淤计算方法。研究表明,交汇区河床形态包括壅水区淤积沙坝、分离区沙洲、输水输沙主槽及分离区以下河段的沙洲等基本元素。进入交汇口上游壅水区的泥沙全部落淤,淤积量随高含沙洪水沙量的增加呈线性线增加;提出的交汇口以下河段的泥沙淤积模式,揭示了泥沙淤积的主要影响因素为支流高含沙洪水沙量、汇流比、恢复饱和系数等,支流高含沙洪水沙量的作用更为明显,该模式可以定量描述交汇口以下河段的泥沙淤积。支流高含沙洪水形成的淤积沙洲的冲刷,取决于干流洪水流量及持续时间。黄河上游交汇区的淤积沙洲,较优的冲刷流量为2000 m3/s左右,冲刷历时为10天左右。
[Abstract]:The intersection area of the upper reaches of the Yellow River is a typical high sediment flow intersection area. The flood of tributaries with high sediment content often causes severe river bed shape adjustment and erosion and siltation changes. The indoor model experiment and field observation data are used. In this paper, the change process of the intersection area and the calculation method of scouring and silting after the tributary high sediment flood enters the main stream are studied. The results show that the river bed form in the intersection area includes the backwater area silting sand dam, the separating area sand bar. Basic elements such as the main channel of water and sediment transport and the sand banks in the lower reaches of the separation area. All the sediments entering the backwater area upstream of the junction are silted, and the amount of sediment deposition increases linearly with the increase of the flood sediment amount of the high sediment content. The model of sediment deposition below the intersection mouth reveals that the main influencing factors of sediment deposition are the high sediment concentration of tributaries, the confluence ratio, the coefficient of recovery saturation and so on, and the effect of the flood sediment content of the tributaries is more obvious. The model can quantitatively describe the silt deposition in the reach below the junction. The erosion of silt banks formed by the high sediment flood of tributaries depends on the flood discharge and duration of the main stream, and the silt sandbanks in the upper reaches of the Yellow River. The optimal scour flow is about 2000 m3 / s and the scour duration is about 10 days.
【作者单位】：黄河水利科学研究院;
【基金】：国家自然科学基金(51379087)
【分类号】：TV147

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