Sensitivity of bed shear stress estimated from vertical velocity profiles: The problem of sampling resolution

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Serval ID
serval:BIB_708D33FE0E6F
Type
Article: article from journal or magazin.
Collection
Publications
Title
Sensitivity of bed shear stress estimated from vertical velocity profiles: The problem of sampling resolution
Journal
Earth Surface Processes and Landforms
Author(s)
Biron P.M., Lane S.N., Roy A.G., Bradbrook K.F., Richards K.S.
ISSN
0197-9337
Publication state
Published
Issued date
1998
Volume
23
Number
2
Pages
133-139
Language
english
Notes
Publication type : Article
Abstract
Bed shear stress in open channel flows is often estimated from the
logarithmic vertical velocity profile, However, most measuring devices
used in the field do not allow for flow velocity to be measured very
close to the bed. The lack of near-bed measurements is a critical loss
of information which may affect bed shear stress estimates. Detailed
velocity profiles obtained from a field acoustic Doppler velocimeter
over three different bed roughnesses clearly show that the inclusion of
near-bed points is critical for the estimation of bed shear stress in a
shallow river environment. Moreover, the results indicate that using
the full flow depth instead of the bottom 20 per cent of the profile
generates an underestimation of the shear stress when flow is uniform.
Keywords
velocity, acoustic Doppler velocimeter, law of the wall, roughness height, displacement height, SEDIMENTARY PROCESSES, BOUNDARY-LAYER, GRAVEL BED, RIVER, FLOW, TRANSPORT
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Create date
03/02/2011 14:41
Last modification date
20/08/2019 14:29
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