Erosion, Sedimentation, and Geomorphology
Dynamics of channel bifurcations in noncohesive sediments
Article first published online: 21 JUN 2003
Copyright 2003 by the American Geophysical Union.
Water Resources Research
Volume 39, Issue 6, June 2003
How to Cite
2003), Dynamics of channel bifurcations in noncohesive sediments, Water Resour. Res., 39, 1162, doi:10.1029/2002WR001434, 6., and (
- Issue published online: 21 JUN 2003
- Article first published online: 21 JUN 2003
- Manuscript Accepted: 14 MAR 2003
- Manuscript Revised: 16 DEC 2002
- Manuscript Received: 7 MAY 2002
- channel bifurcations;
- bank erosion
 Braided rivers produce flow confluences and divergences (diffluences) in roughly equal numbers, but braided river research has focused mainly on confluences. Divergences, however, are of equal importance dynamically: they are sites of formation of central bars and the development of flow divisions that can steer the flow toward one part of the braided network or another. In a series of experiments on flow in isolated, well-defined bifurcations, we found that although a central bar always develops, the divided flow may continue to flow on both sides of the bar (“stable” bifurcation) or may eventually be forced entirely to one side of the bar or the other (“unstable” bifurcation). We found that an unstable bifurcation forms when the flow field is characterized by both a low Shields stress and a nonuniform incoming flow. We also found that divergences with erodible banks tend to an equilibrium configuration that depends mainly on the widening ratio of the channel.