Morphological modelling of rivers with erodible banks

Abstract

Abstract:A bank erosion mechanism and provisions to account for the associated planform changes and input of bank erosion products are added to a two-dimensional, depth-averaged model of river morphology. The model is applied to a reach of the meandering gravel-bed River OhrÏ e (Eger) in the former state of Czechoslovakia. The agreement with observations is poor, but this can be ascribed to shortcomings in the¯ow and bed topography submodels rather than to shortcomings in the bank erosion submodel. Better results are expected when a threedimensional¯ow model, equations for sediment mixtures and a bank accretion mechanism are included. This inclusion will have to be preceded by fundamental research on bank accretion mechanisms and on hiding and exposure eects in the relationship for the in¯uence of gravity pull on sediment transport direction. # 1998 John Wiley & Sons, Ltd.

The importance of high-resolution monitoring in erosion and deposition dynamics studies: examples from estuarine and fluvial systems

“…The PEEP-3 system and the TCT principle offer considerable potential here to test and improve not only geotechnical stability models which attempt to embrace such effects, but also a full range of bank erosion models, assumptions and predictions (e.g. Hasegawa, 1989;Darby, 2000;Mosselman, 2000). This is vital to a sound process understanding of the mechanics of bank instability, the fate of failed material, operation of basal clean-out cycles (Thorne, 1982) and the delivery and storage of bank sediment to river systems, especially time-lags between hydrograph peaks, erosion events, and sediment injection to rivers and estuaries.…”

“…This hinders process specification, because of difficulties in 'matching up' and then quantifying a given response to a specific, imposed stress, which is often a useful route to quantitative exploration of dominant processes and theory testing. For instance, despite the explosion of bank erosion research over the last 15 years, Mosselman (2000) still found that inadequate process specification was one of the many reasons for poor model predictions of bank erosion rates. The hypotheses below illustrate some of these difficulties.…”

Effect of point bar development on the local force balance governing flow in a simple, meandering gravel bed river

“…Another, more recent modeling strategy involves two-and three-dimensional computational fluid dynamics [e.g., Shimizu et al, 1990;Ferguson et al, 2003;Duan and Julien, 2005;Ruther and Olsen, 2007]. These numerical flow simulations have been coupled with models of bed material transport [e.g., Li et al, 2008;Vasquez et al, 2008] and bank erosion [e.g., Mosselman, 1998;Darby et al, 2002;Rinaldi et al, 2008] as a means of predicting the evolution of channel form [e.g., Fischer-Antze et al, 2008].…”

Modelling river and riparian vegetation interactions and related importance for sustainable ecosystem management

“…Deterministic models are usually physically based and use the equations of river morphodynamics (Seminara, 1998; coupled to some empirical model equations of vegetation development. Such models are particularly well developed for meandering rivers (Tubino and Seminara, 1990;Mosselman, 1998;Imran et al, 1999;Zolezzi and Seminara, 2001;, the dynamics of which has been widely investigated via both extensive numerical simulations, and analytical techniques. Promising results have however recently been obtained with regard to the branching dynamics that characterize braided rivers (Murray and Paola, 2003;Bolla Pittaluga et al, 2003;Coulthard et al, 2007;Jang and Shimizu, 2007;Bertoldi et al, 2006;Bertoldi and Tubino, 2007).…”