A model of bank erosion and equilibrium bed topography in river bends

Abstract

In this research a model of bank erosion and bed topography for river bends with erodible banks is presented. The model is based on Bridge's (1992) bed topography model, a bank stability analysis for multi-layered river banks, and a method of estimating the distribution of failed bank materials over the cross-section and their influence on sediment transport. To account for the effects of banks on flow parameters in river bends, the Bridge (1992) model is modified to satisfy the condition of vanishing fluid flux through the banks, and to satisfy the non-slip boundary condition for the longitudinal velocity at the banks. The bank stability analysis accounts for the geotechnical characteristics of the bank materials, the shape of the bank profile, and the role of hydrostatic and pore water pressures (both positive and negative). The key advance of the bank stability analysis implemented in the model is its ability to take into account the effects of multiple horizontal layers of soil, each with different physical properties, within the sedimentary structure of the bank. When tested on two study sites, the new bank stability analysis is found to describe the behaviour of unstable river banks well. Applying the combined model (BEIRM) in several scenarios, indicates that the shape of the flow hydrograph, the river bank height;, and the size distribution of the soil particles that form the river bank, affect the equilibrium bed topography in river bends. However, the initial bank angle and suspended load have little influence on equilibrium bed topography.

More information

Identifiers

Catalogue record

Export record

ASCII CitationAtomBibTeXData Cite XMLDublin CoreDublin CoreEP3 XMLEndNoteHTML CitationHTML CitationHTML ListJSONMETSMODSMPEG-21 DIDLOpenURL ContextObjectOpenURL ContextObject in SpanRDF+N-TriplesRDF+N3RDF+XMLRIOXX2 XMLReferReference ManagerSimple Metadata