Bed Material and Bedload Movement in Two Ephemeral Streams

  1. M. Marzo and
  2. C. Puigdefábregas
  1. M. A. Hassan

Published Online: 14 APR 2009

DOI: 10.1002/9781444303995.ch4

Alluvial Sedimentation

Alluvial Sedimentation

How to Cite

Hassan, M. A. (1993) Bed Material and Bedload Movement in Two Ephemeral Streams, in Alluvial Sedimentation (eds M. Marzo and C. Puigdefábregas), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303995.ch4

Editor Information

  1. Barcelona, Spain

Author Information

  1. Department of Physical Geography, Institute of Earth Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 91904, Israel

  1. Department of Geography, University of British Columbia, Vancouver, British Columbia V6T 1Z2, Canada

Publication History

  1. Published Online: 14 APR 2009
  2. Published Print: 16 SEP 1993

ISBN Information

Print ISBN: 9780632035458

Online ISBN: 9781444303995

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Keywords:

  • bed material and bedload movement;
  • lack of relation between distance of movement and particle size;
  • large portion of bed permanently covered by flowing water;
  • high degree of spatial variability in sediment size;
  • equilibrium in vertical exchange;
  • Sampling bed material- bed has become progressively armoured

Summary

The characteristics of the stream bed material and the transport of individually tagged particles were examined in two ephemeral streams in the Negev and Judean deserts. The bed material shows a high spatial variability in texture between bedforms, between reaches and between the surface and the subsurface. Distance of movement and burial depth are gamma distributed. The study confirmed the lack of relation between the distance of movement and particle size. The movement of the tracer particles and the changes in the armouring ratio over time indicate that the armour was destroyed by large events and re-formed by small and medium events. Most of the tagged particles, after the first flow event, were found in bars. The vertical exchange rate shows that a high percentage of the particles become buried by events.