Sand Dunes

Sand dunes are the only important coastal landform produced by the wind. Wind blowing across a DRY sand surface is able to transport sand grains.

Blown sand accumulates around inanimate objects such as drift wood. Once buried there is no further resistance to wind flow and sand deposition ends. Sand dunes only form when vegetation (e.g. Marram grass) provides the obstacle.

Conditions for dune formation: A plentiful supply of sand. A shallow offshore zone with gentle gradient, where large exposures of sand dry out at low tide. An extensive backshore area where sand can accumulate. Prevailing onshore winds.

Conditions for dune formation:

A plentiful supply of sand.

A shallow offshore zone with gentle gradient, where large exposures of sand dry out at low tide.

An extensive backshore area where sand can accumulate.

Prevailing onshore winds.