Braided Gravel-Bed Rivers with a Limited Width: Preliminary Results of a Hydraulic Model Study

  1. Michael D. Blum2,
  2. Susan B. Marriott3 and
  3. Suzanne F. Leclair4
  1. Christian Marti and
  2. Gian Reto Bezzola

Published Online: 17 MAR 2009

DOI: 10.1002/9781444304350.ch8

Fluvial Sedimentology VII

Fluvial Sedimentology VII

How to Cite

Marti, C. and Bezzola, G. R. (2009) Braided Gravel-Bed Rivers with a Limited Width: Preliminary Results of a Hydraulic Model Study, in Fluvial Sedimentology VII (eds M. D. Blum, S. B. Marriott and S. F. Leclair), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444304350.ch8

Editor Information

  1. 2

    Baton Rouge, Louisiana, USA

  2. 3

    School of Geography and Environmental Management, University of the West of England, Bristol BS16 1QY, UK

  3. 4

    Department of Earth and Environmental Sciences, Tulane University, Dimwiddie Hall, New Orleans, LA 70118, USA

Author Information

  1. Laboratory of Hydraulics, Hydrology and Glaciology (VAW), Swiss Federal Institute of Technology (ETH) Zurich, Gloriastr. 37-39, ETH Zentrum, CH-8092 Zurich, Switzerland

Publication History

  1. Published Online: 17 MAR 2009
  2. Published Print: 15 FEB 2005

Book Series:

  1. Special Publication Number 35 of the International Association of Sedimentologists

Book Series Editors:

  1. Ian Jarvis

Series Editor Information

  1. School of Earth Sciences and Geography, Centre for Earth and Environmental Science Research, Kingston University, Penrhyn Road, Kingston-upon-Thames KT1 2EE, UK

ISBN Information

Print ISBN: 9781405126519

Online ISBN: 9781444304350

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Keywords:

  • limited-width braided gravel-bed rivers;
  • laboratory of Hydraulics, Hydrology and Glaciology (VAW);
  • channel morphology in wide river reaches of finite length;
  • use of hydraulic modelling - well-known technique in civil engineering studies;
  • comparison of bed morphology during high and low bedload transport

Summary

For ecological and flood protection reasons, the current policy of the Swiss Federal Office for Water and Geology is to give rivers more space. In contrast to past river training measures, the spatial needs of a river are no longer defined as being a narrow straight channel. As a result, in some areas, rewidening projects are planned or have already been realized. To understand the morphologically dynamic processes of such rewidened sections, which in most cases lead to braided rivers with a limited width, a research project has been started at the Laboratory of Hydraulics, Hydrology and Glaciology (VAW) of the Swiss Federal Institute of Technology (ETH) in Zurich. This project aims to describe and quantify aggradation, degradation and channel rearrangement during floods by means of numerical and physical modelling of braided rivers. A brief overview of existing work, useful in the design of rewidened channels, is presented, and the experimental set-up at VAW as well as the planned experimental concept for the new study are introduced. The first experiments, accomplished in a laboratory flume with constant discharge, are described. Some preliminary results allow the assumption that a sediment transport formula, developed at VAW, is also applicable for widened areas in steep rivers. It is concluded that a low braiding index in the widened river section implies a high transport capacity and vice versa. The highest transport rate was always observed when a dominant single channel was moving laterally.