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(Article of periodic en Anglais - 2013)

Document title

Spatial variations in surface sediment structure in riffle–pool sequences : a preliminary test of the Differential Sediment Entrainment Hypothesis (DSEH)

Authors(s) and Affiliation(s)

HODGE R.A. (1) ; SEAR D.A. (2) ; LEYLAND J. (2) ;
(1) Dept. of Geography, Science Laboratories, Univ., Durham, ROYAUME-UNI
(2) Geography and Environment, Univ., Southampton, ROYAUME-UNI

Abstract

Riffle-pool sequences are maintained through the preferential entrainment of sediment grains from pools rather than riffles. This preferential entrainment has been attributed to a reversal in the magnitude of velocity and shear stress under high flows; however the Differential Sediment Entrainment Hypothesis (DSEH) postulates that differential entrainment can instead result from spatial sedimentological contrasts. Here the AA. use a novel suite of in situ grain-scale field measurements from a riffle-pool sequence to parameterize a physically-based model of grain entrainment. Field measurements include pivoting angles, lift forces and high resolution digital elevation models (DEMs) acquired using terrestrial laser scanning, from which particle exposure, protrusion and surface roughness were derived. The entrainment model results show that grains in pools have a lower critical entrainment shear stress than grains in either pool exits or riffles. Field data were collected from Bury Green Brook, Hertfordshire, England

Source

Article of periodic

published at : Earth surface processes and landforms / ISSN 0197-9337 / CODEN ESPLDB

Editor : Wiley, Chichester - ROYAUME-UNI (1981)

Millesime : 2013, vol. 38, no5 [pp. 449-465]

Bibliographic references : 1 p.

Collation : 13 fig., 2 tabl.

Language

Anglais

INIST-CNRS, Cote INIST : 17355

Digital Object Identifier

Go to electronic document thanks to its DOI : doi:10.1002/esp.3290

Tous droits réservés © Prodig - Bibliographie Géographique Internationale (BGI), 2014
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