Sand Dunes of the Sahara in Algeria’s Grand Erg Oriental28.3N 3.5E
Winds create long rows of high sand dunes in the Grand Erg Oriental, part of the Sahara Desert in Algeria. Winds over time will sweep desert sand into heaps which, given enough sand, form into a series of hills.
In some types of dunes the slope on the windward side is gradual, on the leeward steep, and such dunes may “roll” forward being blown in the direction of the wind. Vegetation does not survive in the spread of hot dry sand, unless there is water.