Dune

Alternate meanings: Dune (novel) or Dune (movie)

Mesquite Flat Dunes in Death Valley larger image

In physical geography, a dune is a hill of sand built up by the wind. Bare dunes are subject to shifting location and size based on their interaction with the wind. Some species of plants will colonize and stabilize a dune, but they represent a fragile ecosystem.

Some coasts have a row of dunes parallel to them, inward along a long sandy beach, e.g. in the Netherlands, where they are important to protect the land against the sea.

See also:

• The Physics of Blown Sand (1941) by Ralph Bagnold