Fewer than 10% of the world's deserts are covered
by dunes. Sand dunes vary in size depending on the sand supply and wind
direction. Some of the more common types include:
| Name of dune |
Appearance
|
Sand Supply |
Wind strength |
Vegetation |
| Transverse |
. |
abundant |
moderate |
absent |
| Longitudinal |
. |
moderate |
high |
absent |
| Star (seif) |
. |
limited |
variable |
absent |
| Barchan |
 |
limited |
moderate |
absent |
| Parabolic |
. |
abundant |
moderate |
some |
In Florida, the main areas affected by the wind are near beaches. Worldwide
though, it is well to keep in mind that even in deserts, most erosion
is done by running water in patterns similar to those discussed under
the section on streams. |