Quantifying the Effects of Near-Bed Concentration on the Sediment Flux after the Operation of the Three Gorges Dam, Yangtze River

doi:10.3390/w9120986

	Quantifying the Effects of Near-Bed Concentration on the Sediment Flux after the Operation of the Three Gorges Dam, Yangtze River
	He, Li
刊名	WATER
	2017-12-01
卷号	9 期号:12 页码:19
关键词	sediment regime suspended sediment concentration vertical profiles of concentration Jingjiang River Reach Yangtze River
ISSN号	2073-4441
DOI	10.3390/w9120986
通讯作者	He, Li(heli@igsnrr.ac.cn)
英文摘要	The regime of sediment transport in the Jingjiang Reach has significantly changed from quasi-equilibrium to sub-saturation since the impoundment of the Three Gorges Dam (TGD), and vertical profiles of suspended sediment concentration (SSC) have changed accordingly. Vertical profiles of SSC data measured at three hydrological stations in the Jingjiang Reach (Zhicheng, Shaishi, and Jianli), before and after the impoundment of TGD, were collected and analyzed. Analytic results indicate a remarkably large concentration in the near-bed zone (within 10% of water depth from the river-bed) in a sub-saturated channel. The maximum measured concentration was up to 15 times the vertical average concentration, while the ratio in quasi-equilibrium channel was less than four times that. Concentrations normalized with reference concentration at the same height, and may decrease with increasing values of suspension index (settling velocity over shear velocity). In addition, concentration near the water surface may be larger than concentration in the near-bed region when the suspension index is smaller than 0.01. Sediment flux transported in the near-bed zone may be up to 35% of the total sediment flux in unsaturated flows. The relationship between deviations of estimating sediment flux when ignoring the near-bed concentration and discharge in flood season and non-flood season are different in unsaturated and quasi-equilibrium channels. Analysis indicates that, in the quasi-equilibrium channel, more attention should be paid to near-bed concentration during non-flood season, the same as measurements during flood season with larger discharge.
资助项目	National Program on Key Basic Research Project[2016YFC0402303] ; National Natural Science Foundation of China[51579230] ; National Natural Science Foundation of China[51109198]
WOS关键词	LOWER JINGJIANG REACH ; SUSPENDED SEDIMENT ; TURBIDITY MEASUREMENTS ; VERTICAL-DISTRIBUTION ; SEASONAL-VARIATIONS ; FLOW REGIME ; CHINA ; MIDDLE ; CHANGJIANG ; IMPACT
WOS研究方向	Water Resources
语种	英语
出版者	MDPI AG
WOS记录号	WOS:000419225500078
资助机构	National Program on Key Basic Research Project ; National Natural Science Foundation of China
内容类型	期刊论文
源URL	[http://ir.igsnrr.ac.cn/handle/311030/56838]
专题	中国科学院地理科学与资源研究所
通讯作者	He, Li
作者单位	Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Water Cycle & Related Land Surface Proc, Beijing 100101, Peoples R China
推荐引用方式 GB/T 7714	He, Li. Quantifying the Effects of Near-Bed Concentration on the Sediment Flux after the Operation of the Three Gorges Dam, Yangtze River[J]. WATER,2017,9(12):19.
APA	He, Li.(2017).Quantifying the Effects of Near-Bed Concentration on the Sediment Flux after the Operation of the Three Gorges Dam, Yangtze River.WATER,9(12),19.
MLA	He, Li."Quantifying the Effects of Near-Bed Concentration on the Sediment Flux after the Operation of the Three Gorges Dam, Yangtze River".WATER 9.12(2017):19.