DOI: 10.1002/2014GL062900
论文题名: Controls on the geometry of potholes in bedrock channels
作者: Pelletier J.D. ; Sweeney K.E. ; Roering J.J. ; Finnegan N.J.
刊名: Geophysical Research Letters
ISSN: 0094-8974
EISSN: 1944-8705
出版年: 2015
卷: 42, 期: 3 起始页码: 797
结束页码: 803
语种: 英语
英文关键词: bedrock channels
; computational fluid dynamics modeling
; Oregon Coast Range
Scopus关键词: Computation theory
; Computational fluid dynamics
; Fluid dynamics
; Sediment transport
; Shear stress
; Transport properties
; Bedrock channels
; Computational fluid dynamics modeling
; Cylindrical cavities
; Different shapes
; Oregon coast ranges
; Pothole growth
; Roughness elements
; Sediment transport model
; Landforms
; bedrock
; clast
; computational fluid dynamics
; geometry
; sediment transport
; vorticity
; California
; Coast Ranges
; Oregon
; Smith River [California]
; United States
英文摘要: Potholes (circular depressions carved into bedrock) are the dominant roughness elements in many bedrock channels. Here we show, using data from previous studies and new data from the Smith River, Oregon, that pothole depths increase in proportion to both the mean pothole radius (such that the most common pothole depth-to-radius ratio is 2) and the diameter of the largest clasts episodically stored in potholes. We present a theory for these observations based on computational fluid dynamics and sediment transport modeling of vortices in cylindrical cavities of different shapes and sizes. We show that the shear stress at the bottom of a pothole (which controls the rate of pothole growth) is maximized for potholes with a depth-to-radius ratio of approximately 1 and decreases nonlinearly with increasing depth-to-radius ratio such that potholes with depth-to-radius ratios larger than 3 are uncommon. Our model provides a mechanistic explanation for pothole shapes and sizes. © 2015 The Authors. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84925144664&doi=10.1002%2f2014GL062900&partnerID=40&md5=5449d2b1ddff4b00aad9db56f84158d7
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/8590
Appears in Collections: 科学计划与规划 气候变化与战略
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作者单位: Department of Geosciences, University of Arizona, Tucson, AZ, United States
Recommended Citation:
Pelletier J.D.,Sweeney K.E.,Roering J.J.,et al. Controls on the geometry of potholes in bedrock channels[J]. Geophysical Research Letters,2015-01-01,42(3).