Coupled simulations of fluvial erosion and mass wasting for cohesive river banks


Darby, Stephen E., Rinaldi, Massimo and Dapporto, Stefano (2007) Coupled simulations of fluvial erosion and mass wasting for cohesive river banks Journal of Geophysical Research, 112, (F03022), pp. 1-15. (doi:10.1029/2006JF000722).

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Description/Abstract

The erosion of sediment from riverbanks affects a range of physical and ecological issues. Bank retreat often involves combinations of fluvial erosion and mass-wasting, and in recent years bank retreat models have been developed that combine hydraulic erosion and limit equilibrium stability models. In related work, finite element seepage analyses have also been used to account for the influence of pore-water pressure in controlling the onset of masswasting. This paper builds on these previous studies by developing a simulation modeling approach in which the hydraulic erosion, finite element seepage and limit equilibrium stability models are, for the first time, fully coupled. Application of the model is demonstrated by undertaking simulations of a single flow event at a single study site for scenarios where (i) there is no fluvial erosion and the bank geometry profile remains constant throughout, (ii) there is no fluvial erosion but the bank profile is deformed by simulated mass-wasting, and (iii) the bank profile is allowed to freely deform in response to both simulated fluvial erosion and mass-wasting. The results are limited in scope to the specific conditions encountered at the study site, but they nevertheless demonstrate the significant role that fluvial erosion plays in steepening the bank profile, or creating overhangs, thereby triggering mass-wasting. However, feedbacks between the various processes also lead to unexpected outcomes. Specifically, fluvial erosion also affects bank stability indirectly, as deformation of the bank profile alters the hydraulic gradients driving infiltration into the bank, thereby modulating the evolution of the pore-water pressure field. Consequently, the frequency, magnitude and mode of bank erosion events in the fully coupled scenario differ from the two scenarios in which not all the relevant bank process interactions are included.

Item Type: Article
Digital Object Identifier (DOI): doi:10.1029/2006JF000722
Additional Information: This paper is novel in developing the first bank erosion simulation to couple process sub-models that account for the combined effects of fluvial erosion, seepage and mass-wasting. Simulation results provide new insight into the frequency, magnitude and mode of bank erosion events as compared to previous (uncoupled) modelling studies.
ISSNs: 0148-0227 (print)
Related URLs:
Subjects:
ePrint ID: 46669
Date :
Date Event
25 May 2007Submitted
25 August 2007Published
Date Deposited: 13 Jul 2007
Last Modified: 16 Apr 2017 18:33
Further Information:Google Scholar
URI: http://eprints.soton.ac.uk/id/eprint/46669

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