DOI: 10.1016/j.earscirev.2020.103211
论文题名: Textural signatures of sediment supply in gravel-bed rivers: Revisiting the armour ratio
作者: Vázquez-Tarrío D. ; Piégay H. ; Menéndez-Duarte R.
刊名: Earth Science Reviews
ISSN: 00128252
出版年: 2020
卷: 207 语种: 英语
中文关键词: 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
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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/166282
Appears in Collections: 气候变化与战略
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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
Recommended Citation:
Vázquez-Tarrío D.,Piégay H.,Menéndez-Duarte R.. Textural signatures of sediment supply in gravel-bed rivers: Revisiting the armour ratio[J]. Earth Science Reviews,2020-01-01,207