School of Environmental Studies, University of Cape Town, Private Bag, Rondebosch 7700, South Africa.
Variations in wind velocity and sand transport on the windward flanks of desert sand dunes
Article first published online: 14 JUN 2006
Volume 32, Issue 4, pages 581–593, August 1985
How to Cite
LANCASTER, N. (1985), Variations in wind velocity and sand transport on the windward flanks of desert sand dunes. Sedimentology, 32: 581–593. doi: 10.1111/j.1365-3091.1985.tb00472.x
- Issue published online: 14 JUN 2006
- Article first published online: 14 JUN 2006
- (Manuscript received 17 April 1984; revision received 19 November 1984)
The magnitudes of increases in wind velocity, or speed-up factors, have been measured on the windward flanks of transverse and linear dunes of varying height. On transverse dunes, velocity speed-up varied with dune shape and height. For linear dunes, speed-up factors varied principally with wind direction relative to the dune, with dune shape and dune height. The main effect of velocity speed-up on the windward flanks of dunes is to increase potential sand transport rates considerably in crestal areas. This is greatest for large dunes, with winds of moderate velocity blowing at a large angle to the dune. Changing ratios of base to crest sand-transport rates on transverse dunes tend to reduce dune steepness as overall wind velocities increase. On linear dunes, the tendency for crestal lowering is counteracted by deposition in this area when winds reverse in a bi-directional wind regime.