River channel and bar patterns explained and predicted by an empirical and a physics-based method

Auteur(s) et Affiliation(s)



Description :
The AA. compare an empirical stream power-based classification and a physics-based bar pattern predictor. They present a careful selection of data from the literature that contains rivers with discharge and median bed particle size ranging over several orders of magnitude with various channel patterns and bar types, but no obvious eroding or aggrading tendency. Empirically a continuum is found for increasing specific stream power, here calculated with pattern-independent variables: mean annual flood, valley gradient and channel width predicted with a hydraulic geometry relation. ‘Thresholds’, above which certain patterns emerge, were identified as a function of bed sediment size. Bar theory predicts nature and presence of bars and bar mode, here converted to active braiding index (Bi). The most important variables are actual width–depth ratio and nonlinearity of bed sediment transport. Results agree reasonably well with data.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2011, vol. 36, n°. 6, p. 721-738, nombre de pages : 18, Références bibliographiques : 2 p.

Date :
2011

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