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The influence of sediment size, relative grain size and channel slope on initiation of sediment motion in boulder bed rivers. A lichenometric study

Auteur(s) et Affiliation(s)

GOB, F.
Cemagref, Hydrosystem and Bioprocesses, Antony, France
BRAVARD, J.-P.
Univ. Lyon 2, Bron, France
PETIT, F.
Dep. of Geography, Univ., Liège, Belgique


Description :
Using size frequency diagrams and regional growth curves calibrated with dated reference points it is possible to determine the flood event responsible for the last mobilization of each boulder with lichens present. The specific stream power of flood events over the last 60 years is then calculated, and thresholds of sediment transport based on the sediment size are calculated. The results from the 4 studied rivers are compared to similar relationships in the literature. Sediment motion thresholds appear to be very variable within the same type of river (mountainous boulder bed rivers). The critical specific stream power necessary to mobilize a particle of a given diameter may vary by up to 10 times from one river to the next. Bed sediment size and river slope may explain this large range of stream powers.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2010, vol. 35, n°. 13, p. 1535-1547, nombre de pages : 13, Références bibliographiques : 1 p.

Date :
2010

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley

Langue :
Anglais
Droits :
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