Flow in a tightly curving meander bend: effects of seasonal changes in aquatic macrophyte cover

Auteur(s) et Affiliation(s)



Description :
This study analyses a detailed field data set to provide new insights into primary velocity, secondary flow and shear stress distribution. The study site is a low-gradient peatland meander in north-east Germany, with substantial macrophyte cover during summer and autumn. The morphology of the bend was very stable over the observation period and neither bank erosion nor pool scouring occurred. However, fine sediments accumulate within vegetation patches and in the recirculation zones while the remaining open areas tend to erode slightly. With the decay of macrophytes in winter, sediment accumulations are mobilised again and the bathymetry levels, supporting cyclic models of morphologic change in vegetated bends. In the second part of the paper, semi-empirical models for the 3 predominant flow types were tested and discussed; velocity and stress models of vegetated mixing layers and plane turbulent jets, and Rozovskii's model for the transverse flow in bends.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2012, vol. 37, n°. 11, p. 1142-1157, nombre de pages : 16, Références bibliographiques : 1 p.

Date :
2012

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