干旱区生态环境知识资源中心(Arid): Increasing effect of aeolian sediment transport on riverbed evolution under decreased flow conditions in the alluvial desert reach of the Upper Yellow River

Arid

DOI	10.22438/jeb/40/3(SI)/Sp-18
	Increasing effect of aeolian sediment transport on riverbed evolution under decreased flow conditions in the alluvial desert reach of the Upper Yellow River
	Wang, Z.1,2,3; Ta, W.2
通讯作者	Wang, Z.
来源期刊	JOURNAL OF ENVIRONMENTAL BIOLOGY
ISSN	0254-8704
出版年	2019
卷号	40 期号:3 页码:536-547
英文摘要	Aim: In this study, an essential role of bed-material load mainly composed of coarse aeolian sand rather than that of wash-load originating from tributaries of the Loess Plateau in the developmentof channel morphology in response to decreased flows in the alluvial desert reach of the Yellow River is outlined. Methodology: Two sediment cores were drilled in the channel beds of the upstream braided strecth (Shizuishan-Sanhuhekou) and the downstream meandering strecth (Sanhuhekou-Toudaoguai), respectively. Results: The following coarse sediment identification of bed material, grain size distributions (GSDs) in suspension and channel geometry measurement indicated that aeolian and fluvial interactions in our study reach trigger and lead to channel aggradation and lateral migration following the operation of the upstream large reservoirs. In response to the decreased flows in recent 30 decades since 1986, the wash-load proportion of both the braided and the meandering channel increased from 82.98% to 91.09 /0 on average, with the bed material-load proportion decreased from 12.26% to 7.22%, showing an evident tendency of getting finer and channel aggradation. The coarse sediment (0.08-0.25 mm), although only a small fraction of 10% on average, is active in suspension as bed material-load or in saltation as bed-load, indicating that the study channel should be transitional channel or transitional to labile, with the calculated river competence indicator t* as 0.92-2.5. In addition, the primary river stability indicator (K) adapted to the two stretches was proposed and calculated by introducing D50 and bank-full discharge instead of maximum discharge. The calculated values showed that the meandering channel (K=0.647) is more stable than the braded channel (K=0.238), which is of primary guiding significance for alluvial river stability prediction. Interpretation: Deterioration in runoff-sediment relations is increasingly threatening the health of the upper Yellow River. Accordingly, with the decline of the sediment trapping ability of existing reservoirs in the future, erosion rates will increasingly affect the fluvial sediment characteristics and even the channel morphology development.
英文关键词	Aeolian sand Alluvial geomorphology Bed material Channel stability Yellow River
类型	Article
语种	英语
国家	Peoples R China
开放获取类型	Bronze
收录类别	SCI-E
WOS记录号	WOS:000464524700016
WOS关键词	WASH-LOAD ; CHANNEL ; UPSTREAM ; RESERVOIRS ; MORPHOLOGY ; PATTERNS
WOS类目	Environmental Sciences
WOS研究方向	Environmental Sciences & Ecology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/216945
作者单位	1.Lanzhou Univ Technol, Coll Energy & Power Engn, Lanzhou 730050, Gansu, Peoples R China; 2.Chinese Acad Sci, Northwest Inst Ecoenvironm & Resources, Key Lab Desert & Desertificat, Lanzhou 30000, Gansu, Peoples R China; 3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Wang, Z.,Ta, W.. Increasing effect of aeolian sediment transport on riverbed evolution under decreased flow conditions in the alluvial desert reach of the Upper Yellow River[J],2019,40(3):536-547.
APA	Wang, Z.,&Ta, W..(2019).Increasing effect of aeolian sediment transport on riverbed evolution under decreased flow conditions in the alluvial desert reach of the Upper Yellow River.JOURNAL OF ENVIRONMENTAL BIOLOGY,40(3),536-547.
MLA	Wang, Z.,et al."Increasing effect of aeolian sediment transport on riverbed evolution under decreased flow conditions in the alluvial desert reach of the Upper Yellow River".JOURNAL OF ENVIRONMENTAL BIOLOGY 40.3(2019):536-547.