Through erosion and deposition, wind erodes soil from one place and deposits it at another place. This task of deposition becomes possible in exceptional conditions only. Sand dunes are mostly formed in arid and semiarid regions. Difference on regional basis is found in the shape and form of sand dunes.
There shape may be circular, crescent or parabolic. Their height may also vary from a few meters up to 20 meters. Significant difference is also there in slopes on both the sides of sand dunes. They are divided into traversal, parabolic and longitudinal sand dunes.
