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(Article of periodic en Anglais - 2009)

Document title

The linkage between velocity patterns and sediment entrainment in a forced-pool and riffle unit

Authors(s) and Affiliation(s)

THOMPSON D.M. (1) ; WOHL E.E. (1) ;
(1) Dep. of Physics, Astronomy and Geophysics, Connecticut College, New London, ETATS-UNIS

  • Dep. of Geosciences, Colorado State Univ., Fort Collins, ETATS-UNIS

Abstract

Three-dimensional velocities and turbulence intensities were measured with an acoustic Doppler velocimeter at 222 different points at 3 similar flows within a large pool-riffle unit on North Saint Vrain Creek, Colorado. Sediment-sorting patterns were observed with the introduction of 500 tracer particles painted according to initial seeding location. Tracer particles moved sporadically during a 113 day period in response to the annual snowmelt peak flow. Velocity data indicate high instantaneous velocities and turbulence levels in the centre of pools. Patterns of sediment deposition support the notion that stream competence is higher in the pool than the downstream riffle. Flow convergence around a large channel constriction appears to play a major role in multiple processes. Jet flow, flow separation, vortex scour and turbulence generation enhance scour in the centre of pools. Ultimately, multiple processes appear to play some role in maintenance of this forced pool and the associated riffle

Source

Article of periodic

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

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

Millesime : 2009, vol. 34, no2 [pp. 177-192]

Bibliographic references : 1,5 p.

Collation : 12 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.1698

Tous droits réservés © Prodig - Bibliographie Géographique Internationale (BGI), 2009
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