摘要
长江中游宜昌-湖口河段分汊河型分布广泛,涵盖了顺直分汊、微弯分汊及鹅头型分汊3种类型.本文依据三峡水库蓄水以来大量原型观测资料,总结归纳了长江中游各分汊河段的演变特征及其内在机理,并初步预测了其发展趋势.研究结果表明,三峡水库蓄水后,沙量大幅减少,同时局部河床边界条件发生变化,长江中游分汊河段普遍出现支汊冲刷发展、中低滩冲刷变形、高滩滩缘崩退等演变现象.伴随着三峡水库调度方式的不断优化,加之河床冲刷下造床质输移水平的沿程恢复,以及大量航道整治工程的作用,城陵矶以下分汊河段稳定性将优于荆江河段.
The middle Yangtze River from Yichang to Hukou is widely distributed with braided channels, including straight-braided channel, slight bending-braided channel and Goose-head pattern braided channel.Based on plenty of field data, the evolution characteristics and trend of the branching channels were studied. Since the water-impoundment of Three Gorges Reservoir, some new changes appeared in the braided channels in the middle Yangtze River, such as the severe erosion of tributary branch and channel islands. These phenomena are caused by the changes of water-sediment and river boundary conditions. As the operation of Three Gorges Project will continuously optimize, riverbed scouring also makes the bed load transportation on- way recover, and a large number of regulation works of navigation channels would play their role, the stability of braided channels downstream from Chenglingji would be better than Jingjiang reach.
出处
《应用基础与工程科学学报》
EI
CSCD
北大核心
2015年第2期246-258,共13页
Journal of Basic Science and Engineering
基金
国家重点基础研究发展计划(973计划)(2012CB417001)
国家自然科学基金项目(51209013
51009109)
水沙科学与水利水电工程清华大学国家重点实验室(2013-ky-1)
关键词
分汊河道
中枯水支汊
江心洲(滩)
三峡水库蓄水
braided reach
distributary channel
channel inland
the water-impoundment of TGR