These floods continue to move through the land, tearing away rocks and cutting new channels in the land, which produce swift running streams. Through evaporation, these streams eventually vanish, leaving behind deep grooves in the land, and sediments of salt and other minerals. These sediments build up and often form distinct shapes called alluvial fans . Wind is also another important weathering agent in deserts. Even though water is more powerful than wind, wind is still able to erode the land, and transport and deposit materials.
Wind blows across the open spaces of the desert and picks up sand and other sediments.
The force of the wind and sand then wears away, or erodes, the rocks in its path. When the wind loses its force and deposits its sand, dunes are formed. These dunes look like motionless waves . The shapes of these dunes depend on the strength of the wind and the amount of sand it carries. Dunes containing less sand tend to curve, while dunes containing more sand tend to be long and rippling with deep troughs cut between them.