| 摘要: |
| 泥沙在水与河床演变中起到纽带作用，因粒径不同，其运动形态、运动规律以及对河床的作用等不尽相同。因此，研究河床演变就不能轻视泥沙的运动特性，尤其是黄河内蒙河段这种水沙异源的河道。根据实测和实际钻探采样资料，分析了该河段悬移质和河床质的泥沙组成。并以此为基础，从起动扬动、悬浮高度、挟沙能力等角度探讨了主要粒径泥沙在一定水流条件下的运动形态与规律。通过能量和功率方程求得黄河内蒙河段的推移质输沙率。结果表明，内蒙河段悬移质基本上由粒径小于0.080 mm的泥沙组成，而河床质主要粒径为0.100～0.500 mm，其中粒径为0.100～0.250 mm的泥沙活跃于冲淤过程。推移质输沙率的分析表明，来自黄河内蒙古河段上部的粗颗粒泥沙不易被水流长距离挟带，大部分淤积在三湖河口上游。 |
| 关键词: 泥沙组成 运动特点 黄河内蒙河段 推移质 |
| DOI： |
| 分类号:TV142 |
| 基金项目:国家重点基础研究发展计划(973计划)资助项目(2011CB403305) |
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| Sediment fraction and its mechanic movement characteristics in Inner Mongolia reach of Yellow River |
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QIN Yi, LI Ziwen, LIU Qiang, LI Shi, CHEN Xingxing
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State Key Laboratory Base of Eco-hydraulic Engineering in Arid Area, Xi’an University of Technology, Xi’an
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| Abstract: |
| The combination of water and sediment prompts the riverbed evolution. The movement forms, movement rules and the effects on riverbed having different sediment grain sizes are various. Thus, the studies of the riverbed evolution can not despise the sediment fraction and movement characteristics, particularly the studies of the Inner Mongolia reach of the Yellow River, of which water and sediment come from different areas. On the basis of the observed data from the hydrometric stations and by drilling samples, this paper shows the sediment fraction of the suspended material and bed load. Based upon these, the movement forms and rules of the main sediment fraction under certain hydrodynamic conditions are discussed, from the angles of starting velocities, suspended height and silt carrying capacity. The sediment transport rule of the bed load is found by an energy and power equation. The research results show that in the Inner Mongolia reach, the suspended material is mainly composed of the sediment whose grain size is less than 0.08 mm. And the primary partical size of the bed load is from 0.1 mm to 0.5 mm, especially the sediment with partical size between 0.1 mm and 0.25 mm is active during the erosion and deposition of riverbed. The analysis of the bed load transport rate indicates that the most of coarse particle silt, which comes from the upper reach of the Inner Mongolia reach, is too difficult to be carried downstream and will deposit on the riverbed of the upstream of Sanhuhekou. |
| Key words: sediment composition sediment movement characteristics Inner Mongolia reach bed load |
