Cellular model for sand dunes with saltation, avalanche and strong erosion : collisional simulation of barchans
Aeolian features ; Aeolian transport ; Barchan ; Dune ; Earth surface processes ; Experimentation ; Model ; Sand
From the flume experiment,4 distinguishable types of collision patterns between 2 barchans have been observed: coalescence, ejection, split and reorganization. The AA. have proposed a simple cellular model for numerical simulations of dune dynamics
successfully reproduces all the collision patterns. Thus, 3 elementary processes (saltation, avalanche and strong-erosion) are sufficient for a phenomenological description of the interaction dynamics of aqueous barchans. It is also shown that the type
of collision is determined by competition between the filling-up of the interdune between 2 barchans and the change in height of each dune.
A field study of mean and turbulent flow characteristics upwind, over and downwind of barchan dunes
Aeolian features ; Aeolian transport ; Arid area ; Barchan ; Coastal environment ; Dune ; Earth surface processes ; Model ; Namibia ; North-western Namibia ; Shear stress ; Turbulence
The aims of this paper are to present detailed measurements of turbulence (represented here by Reynold stresses) for 2 exemplar barchans in the Skeleton Coast dunefield, Namibia; to assess the effect on turbulent stress estimates of data correction
by rotation to flow streamlines; to consider the implications of these flow data for the geomorphological development of barchan dunes; to compare the results from this study with previous investigations in the field, in wind tunnels and in software models.
Aeolian features ; Aeolian transport ; Barchan ; Canary Islands ; Carbonate ; Dune ; Land use ; Model ; Plant cover ; Sand ; Wind
gives a comparative summary of the main results, based on the following study areas : sand shields and barchans of Famara (Lanzarote), crescentic ridges of Corralejo (NE-Fuerteventura), linear dunes on the leeward coastline of Jandía (S-Fuerteventura
Aeolian features ; Arid area ; Barchan ; Classification ; Desert ; Dune ; Grain size distribution ; Namibia ; Sand
) of the sequences of the granulometric evolution can well be identified. The history of older barchan dunes may also be studied comparably. Some major granulometric sand types, however, cannot be identified with certainty.
Aeolian features ; Aeolian transport ; Arid area ; Barchan ; Dune ; Experimentation ; Oman ; Slope exposure ; Slope gradient ; Turbulence ; Wind speed
Field measurements on an unvegetated, 10 m high barchan dune in Oman are compared with measurements over a 1:200 scale fixed model in a wind tunnel. This particularly concerns the determination of the pattern of shear stress on the windward slope
Aeolian features ; Arid area ; Barchan ; Digital elevation model ; Dune ; Geomorphological mapping ; New Mexico ; Topography ; United States of America
experiment performed on a barchan dune in the White Sands National Monument, New Mexico in January 2003. The 3D surface model of the dune can describe the morphology with hitherto unprecedented detail.
Aeolian features ; Barchan ; China ; Dune ; Geomorphogenesis ; Grain size distribution ; North-Western China ; Topography ; Wind
. This is the main cause for their formation. The evolutionary processes in this region partly support the theory of barchan evolution but do not support the roll-vortex and bimodal wind regime hypotheses.
of their effects and the receding mobility from barchan to sif, silk, ghourd and the most extensive wind drift forms are included. Only the satellite photos made possible the recognition of superordinate regularities and the extremly complex arrangement
Aeolian features ; Aeolian transport ; Antarctica ; Atmospheric circulation ; Barchan ; Climatic change ; Cold area ; Desert ; Dune ; Periglacial features ; Polar region
Meteorological controls on sand transport and changes in dune morphology were monitored for 11 days in November-December 2004 on a barchan dune in the Victoria Valley, McMurdo Dry Valleys. Sand transport in this environment was found
Aeolian transport ; Barchan ; Coastal environment ; Coastal geomorphology ; Model ; New Zealand ; Plant colonization ; Sand ; Sediment transport ; South Island ; Spit
Farewell Spit runs along South Island, New Zealand. The spit is composed of barchan dunes, sand sheets and vegetated linear dunes. Analysis of aerial photography indicates a rapid colonization of the spit by vegetation which has expanded in area