DOI: 10.1002/2014GL060823
论文题名: A model for knickpoint migration in first- and second-order streams
作者: Bressan F. ; Papanicolaou A.N. ; Abban B.
刊名: Geophysical Research Letters
ISSN: 0094-9935
EISSN: 1944-9666
出版年: 2014
卷: 41, 期: 14 起始页码: 4987
结束页码: 4996
语种: 英语
英文关键词: channelized streams
; knickpoint migration
; mechanistic modeling
; semi-cohesive sediments
Scopus关键词: Earth sciences
; Geophysics
; Channel cross section
; channelized streams
; Governing equations
; knickpoint migration
; Mechanistic modeling
; Submerged obstacles
; Theoretical framework
; Time-lapse photographies
; Shear flow
; channel flow
; fluvial geomorphology
; fluvial process
; nappe
; shear stress
; site investigation
; streamflow
; Iowa
; United States
英文摘要: We introduce a new theoretical framework for knickpoint migration in unventilated flows prevalent in channelized semicohesive first- and second-order streams characterized by a sequence of constrictions and expansions in the channel cross section. A key feature of the framework is the inclusion of shear-induced fluvial erosion due to flow suction at the nappe as the key mechanism driving migration. Channel surveys, water stage, time-lapse photography, and laser scans from Mud Creek, Iowa, USA, confirm this unventilated erosive mechanism and reveal a dual advective-diffusive mode of retreat. We treat the fluvial bed shear stress as being similar to the flow on the lee side of a submerged obstacle and derive a governing equation which is a generalized Burgers' equation. The equation is solved to successfully simulate knickpoints monitored in two sites (Iowa and Mississippi), and a modified Peclet number is used to analyze the advective-diffusive nature of the knickpoint migration. © 2014. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84904534964&doi=10.1002%2f2014GL060823&partnerID=40&md5=9f75df2e0dc80002adafc2eb8dfb7528
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/7199
Appears in Collections: 气候减缓与适应
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作者单位: IIHR-Hydroscience and Engineering, University of Iowa, Iowa City, IA, United States
Recommended Citation:
Bressan F.,Papanicolaou A.N.,Abban B.. A model for knickpoint migration in first- and second-order streams[J]. Geophysical Research Letters,2014-01-01,41(14).