干旱区生态环境知识资源中心(Arid): Effects of Wind Velocity and Nebkha Geometry on Shadow Dune Formation

Arid

DOI	10.1029/2019JF005199
	Effects of Wind Velocity and Nebkha Geometry on Shadow Dune Formation
	Zhao, Yongcheng 1,2; Gao, Xin 1,2; Lei, Jiaqiang1,2 ; Li, Shengyu1,2 ; Cai, Dongxu 1; Song, Qin 1,2
通讯作者	Gao, Xin
来源期刊	JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
ISSN	2169-9003
EISSN	2169-9011
出版年	2019
卷号	124 期号:11 页码:2579-2601
英文摘要	Flow dynamics and sand deposition processes over nebkhas were investigated using computational fluid dynamics simulations, wind tunnel experiments, and field measurements. The computational fluid dynamics simulations showed that nebkha width affects both the elongation and broadening of the wind shadows. The length of the wind shadows decreased as the wind shear velocity increased, following a power function, irrespective of the width and height of the nebkha. There are some uncertainties about the effect of the aspect ratio of the nebkha on the formation of wind shadows as a result of the omission of the transport of sand in the simulations. It is suggested that the length of wind shadows is dependent on the absolute values of nebkha width and height rather than the nebkha aspect ratio. Although the numerical results were consistent with the results of the wind tunnel experiments, the wind tunnel experiments showed that the height of the nebkha had a negative effect on the elongation of the shadow dunes. The sedimentary structures revealed by ground-penetrating radar surveys of the dunes in the Taitema Dry Lake, in the eastern Taklimakan Desert, China, showed that the formation of shadow dunes can be divided into three phases. Shadow dunes are initially controlled by horizontal separation flow and then elongate following the same growth mechanisms as linear dunes, eventually breaking up into isolated barchans or short, temporary linear dunes. However, the formation of shadow dunes does not necessarily call for the three phases depending on the local wind regime and sediment supply.
英文关键词	nebkha shadow dune computational modeling wind tunnel simulation sedimentary structure
类型	Article
语种	英语
国家	Peoples R China
开放获取类型	hybrid
收录类别	SCI-E
WOS记录号	WOS:000497169400001
WOS关键词	SECONDARY AIR-FLOW ; AEOLIAN SAND TRANSPORT ; SEDIMENT TRANSPORT ; TUNNEL SIMULATION ; BOUNDARY-LAYER ; LINEAR DUNES ; LEE ; DYNAMICS ; VEGETATION ; PATTERNS
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
EI主题词	2019-11-19
来源机构	中国科学院新疆生态与地理研究所
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/310924
作者单位	1.Chinese Acad Sci, Xinjiang Inst Ecol & Geog, State Key Lab Desert & Oasis Ecol, Xinjiang, Peoples R China; 2.Univ Chinese Acad Sci, Beijing, Peoples R China
推荐引用方式 GB/T 7714	Zhao, Yongcheng,Gao, Xin,Lei, Jiaqiang,et al. Effects of Wind Velocity and Nebkha Geometry on Shadow Dune Formation[J]. 中国科学院新疆生态与地理研究所,2019,124(11):2579-2601.
APA	Zhao, Yongcheng,Gao, Xin,Lei, Jiaqiang,Li, Shengyu,Cai, Dongxu,&Song, Qin.(2019).Effects of Wind Velocity and Nebkha Geometry on Shadow Dune Formation.JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE,124(11),2579-2601.
MLA	Zhao, Yongcheng,et al."Effects of Wind Velocity and Nebkha Geometry on Shadow Dune Formation".JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE 124.11(2019):2579-2601.