Controls on and effects of armoring and vertical sorting in aeolian dune fields: A numerical simulation study - Archive ouverte HAL Access content directly
Journal Articles Geophysical Research Letters Year : 2016

Controls on and effects of armoring and vertical sorting in aeolian dune fields: A numerical simulation study

(1) , (1) , (1)
1

Abstract

Unlike ripples, there are only few numerical studies on grain size segregation at the scale of dunes in aeolian environments. Here we use a cellular automaton model to analyze vertical sorting in granular mixtures under steady unidirectional flow conditions. We investigate the feedbacks between dune growth and the segregation mechanisms by varying the size of coarse grains and their proportion within the bed. We systematically observe the development of a horizontal layer of coarse grains at the top of which sorted bed forms may grow by amalgamation. The formation of such an armor layer controls the overall sediment transport and availability. The emergence of dunes and the transition from barchan to transverse dune fields depend only on the grain size distribution of the initial sediment layer. As confirmed by observation, this result indicates that armor layers should be present in most arid deserts, where they are likely to control dune morphodynamics.
Fichier principal
Vignette du fichier
Geophysical Research Letters - 2016 - Gao - Controls on and effects of armoring and vertical sorting in aeolian dune fields.pdf (1.96 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

insu-03581672 , version 1 (20-02-2022)

Licence

Copyright

Identifiers

Cite

Xin Gao, Clément Narteau, Olivier Rozier. Controls on and effects of armoring and vertical sorting in aeolian dune fields: A numerical simulation study. Geophysical Research Letters, 2016, 43, pp.2614-2622. ⟨10.1002/2016GL068416⟩. ⟨insu-03581672⟩
44 View
9 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More