Transport characteristics of non-uniform suspended sediment in the Jingjiang Reach after the Three Gorges Project operation

被引：0
|
作者：
Feng X. [1 ]
Xia J. [1 ]
Zhou M. [1 ]
Deng S. [1 ]
机构：
[1] State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan
来源：
Hupo Kexue/Journal of Lake Sciences | 2021年 / 33卷 / 06期
关键词：
Jingjiang Reach; Non-equilibrium transport; Non-uniform suspended sediment; Recovery efficiency; Three Gorges Project;
D O I：
10.18307/2021.0623
中图分类号：
学科分类号：
摘要：
The amount of suspended sediment entering the Jingjiang Reach of the middle Yangtze River has been greatly reduced owing to the operation of the Three Gorges Project (TGP), which caused the sediment transport of the reach at a severe non-equilibrium state, and the suspended sediment concentration recovered during the channel scour process. Therefore, the characteristics of non-equilibrium transport of non-uniform suspended sediment were analyzed based on the measured flow and sediment data. In addition, the recovery efficiency was proposed to represent the recovery speed for suspended sediment load, and the corresponding values were calculated annually from 1994 to 2017 based on the measured data of the Jingjiang Reach. Calculated results show that the suspended sediment recovery efficiency of all particle-size groups was very close to zero before the TGP operation, which means that the channel deformation was small during this period. However, the recovery efficiency of each particle-size group increased greatly after the operation of TGP, and the recovery efficiency of coarse sediment (d>0.125 mm) was much higher than that of fine sediment (d<0.125 mm). This is mainly because the content of coarse sediment in bed-material of Jingjiang Reach is large, while the content of fine sediment is relatively small. Finally, empirical relationship was developed between the recovery efficiency and incoming flow-sediment regime, which shows that the recovery efficiency of each group was negatively related to incoming sediment coefficient, with the correlation coefficient for the total, fine and coarse sediment being 0.89, 0.67 and 0.69, respectively. Therefore, it can be concluded that the recovery efficiency of suspended sediment was significantly affected by the incoming flow and sediment conditions. © 2021 by Journal of Lake Sciences.
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页码：1898 / 1905
页数：7
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