Niveau: Supérieur, Doctorat, Bac+8
Mobile Bank Conditions for Laminar Micro-Rivers Olivier Devauchelle?, Christophe Josserand†, Pierre-Yves Lagree†and Stephane Zaleski† February 29, 2008 Abstract The present study aims to establish a simple mechanistic model for river bank erosion. Recent experiments demonstrate that small-scale laminar flumes can develop erosion structures similar to those encountered in Nature. From Saint-Venant's Equations, a classical sediment transport law and a simple avalanche model, it is shown that bank failure caused by flow erosion can be represented through simple boundary conditions. These conditions are able to deal with the water level adjustment imposed by a constant water outflow condition. Finally, they are implemented to approach numerically the widening of a laminar river. Keywords: river morphology, bank erosion, bedload transport, micro scale experiment Resume La presente etude se donne pour objectif d'etablir un modele simple de berge erodable. De recentes contributions ont demontre experimentalement que dans des micro-rivieres de laboratoire, parcourues par un ecoulement laminaire, l'erosion peut produire des structures similaires a celles observees en milieu naturel. Les equations de Saint-Venant en regime laminaire associees a une loi de transport sedimentaire classique ainsi qu'a un modele simplifie d'avalanche, permettent de determiner un ensemble de conditions aux limites decrivant l'effondrement des berges sous l'effet de l'erosion, et capables de prendre en compte des variations du niveau de l'eau de l'ecoulement.
- equations
- flux
- sediment transport
- avalanche
- bank model
- equations de saint-venant en regime laminaire
- small-scale laminar
- laminar flume
- micro