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| Titel |
The morphodynamic impact of vegetation and large wood on fluvial systems |
| VerfasserIn |
L. Mao, W. Bertoldi, F. Comiti, A. M. Gurnell, S. J. McLelland, N. Osei, D. Ravazzolo, M. Tal, M. Welber, S. Zanella |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250062296
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| Zusammenfassung |
| We present preliminary results from a set of recent experiments conducted in the Total Environment Simulator flume at the University of Hull in the framework of the Hydralab IV EU project. The aim of these experiments is to identify and assess the effects of riparian vegetation and large wood on the morphodynamics of braided river channels. The type and size of riparian vegetation is known to play a crucial role in shaping rivers, acting as a proper riparian engineer. Riparian vegetation influences bank stability, increases mean channel depth and can affect planform pattern by reducing the number of active branches. However, the geomorphic effect of plants can continue well after their erosion from banks. As dead or living pieces of large wood are transported through the fluvial network, they can exert a tremendous influence on river erosion and sedimentation processes, channel morphology, channel hydraulics, and ecological diversity of river channels. Our experiments consisted of different scenarios of presence / absence of riparian vegetation (simulated using alfalfa sprouts) and large wood density (simulated using wooden dowels). The experiments were designed to assess both the individual effects of woody debris and bank vegetation, as well as their combined effects. Each experiment has been characterised in terms of planform configuration (the number of active branches per cross-section) and bed topography (surveyed by a terrestrial laser scanner). Detailed DEM differencing was used to investigate sediment transport patterns and dynamics for the different vegetation-wood scenarios. The results of this work will help improve the ability to predict the response of river systems to different disturbances and management strategies. |
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