Abstract
It is generally acknowledged that riparian vegetation influences the geomorphological dynamics of rivers. However, the precise nature of the impact depends on a wide range of ecological and geomorphological processes, making it difficult to isolate the effects of specific individual factors in a field setting. As a result, there are many uncertainties concerning the effects of riparian vegetation on channel morphology, riverbank erosion and meander migration. In this study an alternative approach, using controlled numerical experiments, is developed to address these issues. The numerical model used herein is based on a coupled fluvial-geotechnical model, mRIPA, which combines a two-dimensional flow and sediment transport model with a geotechnical bank-stability analysis. In this study mRIPA is developed further by introducing additional submodels designed to account for the hydraulic and geotechnical effects of riparian vegetation. The new version of mRIPA is used to simulate a range of vegetation scenarios to explore the possible influence of vegetation density and biophysical characteristics of vegetation on geomorphological change. Results show that riparian trees can have a considerable impact on channel planform evolution and, to a lesser extent, bed topography. In particular, it is found that vegetation is usually stabilizing on the reach scale, although it can be locally destabilizing. Vegetation density and root structure are identified as the parameters that exert most influence over channel morphology.
Original language | English |
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Title of host publication | Riparian Vegetation and Fluvial Geomorphology |
Editors | Sean J. Bennett, Andrew Simon |
Publisher | American Geophysical Union |
Pages | 267-282 |
Number of pages | 16 |
ISBN (Print) | 0875903576, 9780875903576 |
DOIs | |
Publication status | Published - 2004 |
Externally published | Yes |
Keywords
- Geomorphology
- Riparian plants
- River channels
- Sediment transport
ASJC Scopus subject areas
- Arts and Humanities(all)