A Few Things You Should Know About Sand Dunes But Were Afraid To Ask

Walvis Bay lies at the edge of the Namib Sand Sea in the west of Namibia, consisting of several large areas of sand dunes lying along the coastal region.
The image of the landscape of this particular area between Luderitz and Walvis Bay, is possibly how most people think of Namibia, the pictures of massive sand dunes are quite impressive and are photographed and published often.

This area befittingly known as the sand sea, contains different types of dunes, mainly barchan dunes and transverse dunes and covers an area roughly 400 kilometres in length and is between 150 and 100 kilometres in width.
A barchan dune is one that is roughly arc shaped, and has two long sides with a curved part between them, this part is known as the slip face, which is generally around 32 degrees, which is the angle of repose for dune sand, the other side (the windward side) of the dune is at a much shallower angle of approximately 15 degrees.

As with most sand dunes, there is an enormous variation in size, they range from hundreds of metres to just a few metres.
They migrate by being constantly blown along by the wind, which blows the sand up the windward side, where it drops over the slip face, thereby causing the whole thing to move along with the wind.