The University of Southampton
University of Southampton Institutional Repository

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

Coupled simulations of fluvial erosion and mass wasting for cohesive river banks
Coupled simulations of fluvial erosion and mass wasting for cohesive river banks
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.
0148-0227
1-15
Darby, Stephen E.
4c3e1c76-d404-4ff3-86f8-84e42fbb7970
Rinaldi, Massimo
37a99621-c79d-4555-8d99-ea59c499c12f
Dapporto, Stefano
10b3abb1-895b-4d2f-bdbe-415aa3385d03
Darby, Stephen E.
4c3e1c76-d404-4ff3-86f8-84e42fbb7970
Rinaldi, Massimo
37a99621-c79d-4555-8d99-ea59c499c12f
Dapporto, Stefano
10b3abb1-895b-4d2f-bdbe-415aa3385d03

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), 1-15. (doi:10.1029/2006JF000722).

Record type: Article

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.

This record has no associated files available for download.

More information

Submitted date: 25 May 2007
Published date: 25 August 2007
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.

Identifiers

Local EPrints ID: 46669
URI: http://eprints.soton.ac.uk/id/eprint/46669
ISSN: 0148-0227
PURE UUID: 5f54ac88-8210-451d-b089-95218b6feeb9
ORCID for Stephen E. Darby: ORCID iD orcid.org/0000-0001-8778-4394

Catalogue record

Date deposited: 13 Jul 2007
Last modified: 16 Mar 2024 02:59

Export record

Altmetrics

Contributors

Author: Massimo Rinaldi
Author: Stefano Dapporto

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×