气候变化领域集成服务门户(CCPortal): Textural signatures of sediment supply in gravel-bed rivers: Revisiting the armour ratio

CCPortal

DOI	10.1016/j.earscirev.2020.103211
	Textural signatures of sediment supply in gravel-bed rivers: Revisiting the armour ratio
	Vázquez-Tarrío D.; Piégay H.; Menéndez-Duarte R.
发表日期	2020
ISSN	00128252
卷号	207
英文摘要	The surface of the streambed in gravel-bed rivers is commonly coarser than the underlying bed material. This surface coarsening, or ‘armouring’, is usually described by means of the ratio between surface and subsurface grain-size metrics (the ‘armour ratio’). Such surface coarsening is typical of river reaches that are degrading due to a deficit in sediment supply (e.g. gravel-bed reaches below dams or lakes), but non-degrading gravel-bed streams may also exhibit some degree of armouring in relation to specific hydrological patterns. For instance, selective transport during the recession limbs of long lasting floods may coarsen the bed more significantly than flash floods. Consequently, regional differences in bed coarsening should exist, reflecting in turn the variability in sediment and water regimes. In this paper, we explore the trends linking armour ratios to sediment supply, taking into account the differences in hydrological context. We based our analysis on a large data set of bedload and grain size measurements from 49 natural gravel-bed streams and four flume experiments compiled from the scientific literature. Our main outcome documents how the balances between sediment yields and transport capacities have a quantifiable reflection on the armour ratios measured in the field: we report statistically significant correlations between bedload fluxes and surface grain-size, and an asymptotic rise in armour ratios with the decline of sediment supply. Hydrological controls are also observed. Additionally, the trends observed in the field data are comparable to those previously documented in flume experiments with varying sediment feed. In this regard, different kinds of bedforms and particle arrangements have been commonly described with progressive reductions in sediment inputs and the subsequent coarsening of the streambed. Hence, armour ratios serve as a proxy for the general organization of the streambed of gravel-bed streams, and our results quantify this streambed adjustment to the dominant sediment regime. © 2020 Elsevier B.V.
关键词	Armour ratio Bedload Gravel-bed rivers Sediment supply
英文关键词	bedload; data set; flume experiment; fluvial deposit; grain size; gravel bed stream; hydrology; sediment transport; sediment yield; texture
语种	英语
来源期刊	Earth Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203913
作者单位	University of Lyon, CNRS UMR 5600 EVS, Site ENS, Lyon, F-69342, France; Department of Geology, University of Oviedo, c/ Jesús Arias de Velasco, s/n, Oviedo, 33005, Spain; INDUROT, University of Oviedo, Campus de Mieres, s/n, Mieres, 33600, Spain
推荐引用方式 GB/T 7714	Vázquez-Tarrío D.,Piégay H.,Menéndez-Duarte R.. Textural signatures of sediment supply in gravel-bed rivers: Revisiting the armour ratio[J],2020,207.
APA	Vázquez-Tarrío D.,Piégay H.,&Menéndez-Duarte R..(2020).Textural signatures of sediment supply in gravel-bed rivers: Revisiting the armour ratio.Earth Science Reviews,207.
MLA	Vázquez-Tarrío D.,et al."Textural signatures of sediment supply in gravel-bed rivers: Revisiting the armour ratio".Earth Science Reviews 207(2020).