气候变化领域集成服务门户(CCPortal): Dunes in the world’s big rivers are characterized by low-angle lee-side slopes and a complex shape

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DOI	10.1038/s41561-019-0511-7
	Dunes in the world’s big rivers are characterized by low-angle lee-side slopes and a complex shape
	Cisneros J.; Best J.; van Dijk T.; Almeida R.P.; Amsler M.; Boldt J.; Freitas B.; Galeazzi C.; Huizinga R.; Ianniruberto M.; Ma H.; Nittrouer J.A.; Oberg K.; Orfeo O.; Parsons D.; Szupiany R.; Wang P.; Zhang Y.
发表日期	2020
ISSN	17520894
卷号	13 期号:2
英文摘要	Dunes form critical agents of bedload transport in all of the world’s big rivers, and constitute appreciable sources of bed roughness and flow resistance. Dunes also generate stratification that is the most common depositional feature of ancient riverine sediments. However, current models of dune dynamics and stratification are conditioned by bedform geometries observed in small rivers and laboratory experiments. For these dunes, the downstream lee-side is often assumed to be simple in shape and sloping at the angle of repose. Here we show, using a unique compilation of high-resolution bathymetry from a range of large rivers, that dunes are instead characterized predominantly by low-angle lee-side slopes (<10°), complex lee-side shapes with the steepest portion near the base of the lee-side slope and a height that is often only 10% of the local flow depth. This radically different shape of river dunes demands that such geometries are incorporated into predictions of flow resistance, water levels and flood risk and calls for rethinking of dune scaling relationships when reconstructing palaeoflow depths and a fundamental reappraisal of the character, and origin, of low-angle cross-stratification within interpretations of ancient alluvial sediments. © 2020, The Author(s), under exclusive licence to Springer Nature Limited.
语种	英语
scopus关键词	alluvial deposit; bathymetry; bed roughness; bedform; bedload; fluvial deposit; stratification
来源期刊	Nature Geoscience
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/124512
作者单位	Department of Geology, University of Illinois at Urbana Champaign, Urbana, IL, United States; Departments of Geography & GIS, Mechanical Science and Engineering and Ven Te Chow Hydrosystems Laboratory, University of Illinois at Urbana Champaign, Urbana, IL, United States; Department of Applied Geology and Geophysics, Deltares, Utrecht, Netherlands; Instituto de Geociências, Universidade de São Paulo, São Paulo, Brazil; Instituto de Energia e Ambiente, Universidade de São Paulo, São Paulo, Brazil; Instituto Nacional de Limnologìa, National Scientific and Technical Research Council, Santa Fe, Argentina; Ohio-Kentucky-Indiana Water Science Center, US Geological Survey, Louisville, KY, United States; Faculdade de Tecnologia, Universidade Estadual de Campinas, Limeira, Brazil; Central Midwest Water Science Center, US Geological Survey, Rolla, MO, United States; Instituto de Geociências, Universidade de Brasília, Brasília, Brazil; Department of Earth, Environmental and Planetary Sciences, Rice University, Houst...
推荐引用方式 GB/T 7714	Cisneros J.,Best J.,van Dijk T.,等. Dunes in the world’s big rivers are characterized by low-angle lee-side slopes and a complex shape[J],2020,13(2).
APA	Cisneros J..,Best J..,van Dijk T..,Almeida R.P..,Amsler M..,...&Zhang Y..(2020).Dunes in the world’s big rivers are characterized by low-angle lee-side slopes and a complex shape.Nature Geoscience,13(2).
MLA	Cisneros J.,et al."Dunes in the world’s big rivers are characterized by low-angle lee-side slopes and a complex shape".Nature Geoscience 13.2(2020).