Form roughness and the absence of secondary flow in a large confluence-diffluence, Rio Parana, Argentina

Détails

ID Serval
serval:BIB_945C4DC33537
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Form roughness and the absence of secondary flow in a large confluence-diffluence, Rio Parana, Argentina
Périodique
EARTH SURFACE PROCESSES AND LANDFORMS
Auteur(s)
Parsons D:R. , Best J.L., Lane S.N., Orfeo O., Hardy R.J., Kostaschuk R.
ISSN
0197-9337
Statut éditorial
Publié
Date de publication
2007
Volume
32
Numéro
1
Pages
155-162
Langue
anglais
Notes
Publication type : Editorial Material
Résumé
Confluence-diffluence units are key elements within many river
networks, having a major impact upon the routing of flow and sediment,
and hence upon channel change. Although much progress has been made in
understanding river confluences, and increasing attention is being paid
to bifurcations and the important role of bifurcation asymmetry, most
studies have been conducted in laboratory flumes or within small rivers
with width:depth (aspect) ratios less than 50. This paper presents
results of a field-based study that details the bed morphology and 3D
flow structure within a very large confluence-diffluence in the Rio
Parana, Argentina, with a width:depth ratio of approximately 200. Flow
within the confluence-diffluence is dominated largely by the bed
roughness, in the form of sand dunes; coherent, channel-scale,
secondary How cells, that have been identified as important aspects of
the flow field within smaller channels, and assumed to be present
within large rivers, are generally absent in this reach. This finding
has profound implications for flow mixing rates, sediment transport
rates and pathways, and thus the interpretation of
confluence-diffluence morphology and sedimentology.
Mots-clé
confluence, diffluence, large river, secondary flow, Parana River, RIVER CHANNEL CONFLUENCES, NUMERICAL-SIMULATION, STREAM CONFLUENCES, BED MORPHOLOGY, CENTRAL REGION, JAMUNA RIVER, CIRCULATION, BIFURCATION, BANGLADESH, TRANSPORT
Web of science
Création de la notice
03/02/2011 15:40
Dernière modification de la notice
20/08/2019 15:56
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