Sand Dunes

What is a sand dune ?

A sand dune is a hill made out of sand created by a series of winds.

They form in Different shapes and sizes

How they form- Wind blows by the area picking up sand particles.- As the wind loses energy it drops the sand suspended within it-Over a long period of time( also with varied winds and textures of sand ) distinctive dune shapes are created

BarchansA crescent-shaped sand dune with “horns” of the dune pointing downwind

Transverse DunesA giant ripple-like sand dune formed at a right angle to the direction of the prevailing winds

Parabolic DunesDispositional features made of hills of sand that are stabilized by vegetation at each end

Longitudinal Dunes

Dispositional feature formed when wave action drags sand along the shoreline as waves break at angles on the earths surface

Star DunesA sand that resembles a star because the wind direction is variable

Human Impacts- Land development and recreational uses

-Alteration, people protecting sand from coming into residential areas- building dirt jumps on them

Affecting

Protecting

Some countries have created groups to protect sand dunes ( sand dune stabilization )

Natural Impacts -Provides food for organisms-Provides camouflage

-Re shapes the land-Destroys vegetation- Excessive erosion