| 孙昭华,李义天,黄 颖,高凯春.长江中游城陵矶- 湖口分汊河道洲滩演变及碍航成因探析[J].水利学报,2011,42(12): |
| 长江中游城陵矶- 湖口分汊河道洲滩演变及碍航成因探析 |
| Fluvial process of sandbars and shoals in branching channels of the middle Yangtze River |
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| DOI： |
| 中文关键词: 长江中游 分汊河道 洲滩演变 碍航浅滩 |
| 英文关键词: middle Yangtze River branching channel sandbars shoals |
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| 中文摘要: |
| 在归纳总结分汊河道演变特征的基础上，结合长江中游城陵矶- 湖口分汊河道洲滩演变及航道条件变化的观测资料，对碍航问题的成因进行了分类剖析。结果表明：由于边界条件的制约，顺直或顺直分汊河道的长度、宽度的变化受到限制，边滩缓慢下移、心滩左右摆动；弯曲分汊河道受到进口挑流作用和弯曲汊道不断蜿蜒摆动的影响，主流频繁移位，以上因素造成一些河段内河势周期调整并伴随浅滩条件恶化，一些河段对来水来沙适应性差而频繁出浅。从本质上而讲，本河段内浅滩碍航的深层次原因是由于河床演变具有多重河型属性，低矮洲滩难以稳定，水沙输移在时间和空间上难以平稳衔接，对浅滩的治理需要注意以上特征。 |
| 英文摘要: |
| In this paper ，the dynamic features of shoaling reaches in branching channel of the middle Yangtze River is studied，and the factors affecting its fluvial process is classified based on the knowledge of the morphological behaviors in the past decades. Comparison of contour plan in different periods with different reaches shows that the mechanism of changes of shoaling reach can be divided into two kinds. In reaches with straight plan，the length and width of channel is restricted by rocks and sediment bars moving gradually in longitudinal direction. That causes the location and deposition of shoals change frequently in different years. In reaches with bend plan ，channel thalweg changes with the meandering breach and hydrological regime. That causes the condition of shoals change not only with configuration of sandbars but also with discharge and sediment supply. Although it may be pos-sible to identify the channel pattern as branched type ，the different fluvial behavior between flood and dry season implies that the channel system has a multi-channel pattern type of straight and meandering. The changes of sandbars and shoals can only be understood based on considering those features. |
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