Abstract Barchan dunes of the Kharga Depression, Western Desert, Egypt, have been assessed in terms their morphometry, grain size, and migration rate using remote sensing GIS techniques field laboratory work. Thirty-seven sites were chosen along dune belt subdivided into northern, central, southern sectors. At each site, several barchans subjected to morphometric measurements (length, width, he...

We use FLUENT to calculate the wind profile over barchans and transverse dunes. The form of the streamlines of flow separation at the lee side of the dunes is determined for a symmetric barchan dune in three dimensions, and for the height profile of a measured transverse dune field in the Lençóis Maranhenses.

Barchan dunes were found to transform into parabolic dunes and vice versa when the amount of vegetation on and around them changes. This work presents the first numerical simulation of this effect. We propose a continuum model for the density of vegetation. An established sand transport model is used for simulating the evolution of the dunes.

We use FLUENT to calculate the wind profile over barchans and transverse dunes. The form of the streamlines of flow separation at the lee side of the dunes is determined for a symmetric barchan dune in three dimensions, and for the height profile of a measured transverse dune field in the Lençóis Maranhenses.

We present a model to describe the collective motion of barchan dunes in a field. Our model is able to reproduce the observation that a typical dune stays confined within a stripe. We also obtain some of the pattern structures which ressemble those observed from aerial photos which we do analyse and compare with the specific field of Laâyounne.

Gravity-driven grainflows on aeolian dunes are important agents of sand transport Earth and Mars but have been the focus few field studies. We present results from first comprehensive study to evaluate hypotheses posed by previous studies: (a) grainflow frequency depends rate; (b) magnitude is independent (c) speed its area. A barchan slipface was monitored with a terrestrial laser scanner vide...