This animation presents a desert landscape, made up of rocks and sand, which, under the action of the wind, is shaped into a rock desert (reg) and a dune desert (erg).
In deserts, the principal agent of erosion and transport of material is the wind. If the wind can act so effectively to erode and to transport particles, this is because there is neither humidity nor vegetation to retain and stabilize materials. The wind that sweeps the surface of the ground thus easily carries particles of the size of sand grains, but does not have the energy needed to lift or displace larger particles. Thus, the larger particles become progressively more concentrated as sand is removed, resulting in a sort of pavement that covers the sand and so stabilizes it.