Particle Dislodgement from a Flat Sand Bed by Wind: A Re-Analysis of Willetts & Rice's Data

  1. K. Pye2 and
  2. N. Lancaster3
  1. B. B. Willetts and
  2. I. K. McEwan

Published Online: 8 APR 2009

DOI: 10.1002/9781444303971.ch1

Aeolian Sediments: Ancient and Modern

Aeolian Sediments: Ancient and Modern

How to Cite

Willetts, B. B. and McEwan, I. K. (1993) Particle Dislodgement from a Flat Sand Bed by Wind: A Re-Analysis of Willetts & Rice's Data, in Aeolian Sediments: Ancient and Modern (eds K. Pye and N. Lancaster), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303971.ch1

Editor Information

  1. 2

    Reading, UK

  2. 3

    Reno, Nevada, USA

Author Information

  1. Department of Engineering, University of Aberdeen, King's College, Aberdeen AB9 2UE, UK

Publication History

  1. Published Online: 8 APR 2009
  2. Published Print: 27 MAY 1993

ISBN Information

Print ISBN: 9780632035441

Online ISBN: 9781444303971



  • aeolian sediments and modern aeolian environments;
  • particle dislodgement from flat sand bed by wind;
  • numerical simulations of aeolian saltation;
  • change induced by saltation in near-bed wind;
  • understanding aeolian transport and role of inter-grain collision;
  • dislodgement rate against shear velocity;
  • excursion length distribution for full grain population;
  • simulation of grain progress from coloured strip to trap


A number of numerical simulations of aeolian saltation have been constructed in the last few years, each requiring independent checks to ensure its validity. The object of this paper is to demonstrate compatibility between data calculated by one of these saltation models (McEwan & Willetts, 1991) and experimentally derived data from tracer grain experiments. The experiments are discussed with reference to two numerical simulations. Firstly, the depletion of dyed grains from a coloured strip is modelled, enabling dislodgement rates to be calculated. This simulation is a reworking of dislodgement data previously published by Willetts & Rice (1988); an important component in this reworking is an exponential reptation length distribution derived from the saltation model of McEwan & Willetts (1991). Importantly, the revised values of dislodgement rate calculated show closer agreement with other published work (Anderson, 1986; Jensen & Sorensen, 1986; Williams et al., 1990). Secondly, the progress of the coloured grains toward a creep trap placed downwind of the coloured strip is modelled, again using an excursion length distribution calculated by the saltation model. A reasonable match is found between the calculated and experimentally measured grain arrival curves.