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Dune

A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill.[1] An area with dunes is called a dune system[2][3][4][5] or a dune complex.[6] A large dune complex is called a dune field,[7] while broad, flat regions covered with wind-swept sand or dunes, with little or no vegetation, are called ergs or sand seas.[8][9][10] Dunes occur in different shapes and sizes, but most kinds of dunes are longer on the stoss (upflow) side, where the sand is pushed up the dune, and have a shorter slip face in the lee side.[11] The valley or trough between dunes is called a dune slack.[12]

For the fiction franchise, see Dune (franchise). For other uses, see Dune (disambiguation).

Dunes are most common in desert environments, where the lack of moisture hinders the growth of vegetation that would otherwise interfere with the development of dunes. However, sand deposits are not restricted to deserts, and dunes are also found along sea shores, along streams in semiarid climates, in areas of glacial outwash, and in other areas where poorly cemented sandstone bedrock disintegrates to produce an ample supply of loose sand.[13] Subaqueous dunes can form from the action of water flow (fluvial processes) on sand or gravel beds of rivers, estuaries, and the sea-bed.[14][15]


Some coastal areas have one or more sets of dunes running parallel to the shoreline directly inland from the beach. In most cases, the dunes are important in protecting the land against potential ravages by storm waves from the sea.[16] Artificial dunes are sometimes constructed to protect coastal areas.[17][18] The dynamic action of wind and water can sometimes cause dunes to drift, which can have serious consequences. For example, the town of Eucla, Western Australia, had to be relocated in the 1890s because of dune drift.[19]


The modern word "dune" came into English from French around 1790,[20] which in turn came from Middle Dutch dūne.[14]

Aeolian dunes[edit]

Aeolian dune shapes[edit]

Five basic dune types are recognized: crescentic, linear, star, dome, and parabolic. Dune areas may occur in three forms: simple (isolated dunes of basic type), compound (larger dunes on which smaller dunes of same type form), and complex (combinations of different types).[24]

in the Eastern Cape, South Africa[63]

Alexandria Coastal Dunefields

Witsand Nature Reserve in the , South Africa

Kalahari Desert

The white dunes of , South Africa

De Hoop Nature Reserve

The dunes of the , a desert part of the Great Rift Valley in northwestern Kenya

Suguta Valley

The dunes of the , northeastern Ethiopia toward the border with Eritrea

Danakil Depression

The dunes of in the greater Namib-Naukluft National Park, Namibia

Sossusvlei

in northern Nigeria

Chad Basin National Park

The coastal dunes of in the southwesternmost part of Angola

Iona National Park

in the Kgalagadi Transfrontier Park, the southwesternmost part of Botswana

Khawa dunes

in the city of Gao in northern Mali near the Niger River

La Dune Rose

in southeastern Mauritania extending into Mali

Erg Aoukar

in southwestern Algeria and northern Mali

Erg Chech

and Erg Chigaga in southern Morocco

Erg Chebbi

in northeastern Algeria and southern Tunisia

Grand Erg Oriental

in western Algeria

Grand Erg Occidental

The and the Idehan Murzuq in southwestern Libya

Idehan Ubari

The dunes in the Canary Islands, Spain

Corralejo

The in southeastern Libya

Rebiana Sand Sea

The in southeastern Libya and southwestern Egypt

Great Sand Sea

The Selima Sand Sheet in northwestern

Sudan

The dunes of the in northern Sudan

Bayuda Desert

The dunes of the in northwestern Senegal

Lompoul Desert

The coastal dunes of , Mozambique

Bazaruto Island

in northern Chad

Erg du Djourab

The dunes of the in northeastern Chad

Mourdi Depression

The dunes of , in southeastern Niger

Tin Toumma Desert

in the Ténéré, in northern Niger

Grand Erg de Bilma

The dunes of in the Sahel Region, northern Burkina Faso

Oursi

's Shifting Sands near Olduvai Gorge

Tanzania

(2012) [1941]. The Physics of Blown Sand and Desert Dunes. Courier Dover Publications. ISBN 978-0-486-14119-0.

Bagnold, Ralph

Ralph Lorenz; James Zimbelman (2014). Dune Worlds: How Wind-blown Sand Shapes Planetary Landscapes. Springer.  978-3-540-89724-8.

ISBN

Anthony J. Parsons, A. D. Abrahams, ed. (2009). Geomorphology of Desert Environments. Springer.  978-1-4020-5718-2.

ISBN

Pye, Kenneth; Tsoar, Haim (2009). Aeolian Sand and Sand Dunes. Springer.  978-3-540-85909-3.

ISBN

. NASA Earth Observatory. Archived from the original on 30 September 2006. Retrieved 28 April 2006.

"Nouakchott, Mauritania"

Badescu, V.; Cathcart, R. B.; Bolonkin, A. A. (2008). "Sand dune fixation: A solar-powered Sahara seawater pipeline macroproject". Land Degradation & Development. 19 (6): 676–691. :10.1002/ldr.864. S2CID 128961228.

doi

. Desert Processes Working Group; Knowledge Sciences, Inc. Archived from the original on 21 October 2010. Retrieved 6 October 2010.

"Summary: Dunes, Parabolic"

. Les dossiers thématiques du CSFD. Archived from the original on 25 July 2011. Retrieved 4 January 2011.

"Fighting wind erosion. One aspect of the combat against desertification"

Loibor Seder Kenya's Biggest Sand Dune

Coastal Sand Dunes

Dune pattern identification, U.S. Army

The Bibliography of Aeolian Research