Guelta

A guelta ( ar, قلتة, also transliterated qalta or galta; Berber: agelmam) is a pocket of water that forms in drainage canals or

wadis Wadi ( ar, وَادِي, wādī), alternatively ''wād'' ( ar, وَاد), North African Arabic Oued, is the Arabic term traditionally referring to a valley. In some instances, it may refer to a wet ( ephemeral) riverbed that contains water on ...

in the

Sahara , photo = Sahara real color.jpg , photo_caption = The Sahara taken by Apollo 17 astronauts, 1972 , map = , map_image = , location = , country = , country1 = , ...

. The size and duration will depend on the location and conditions. It may last year-round through the dry season if fed by a source such as a spring. When a river (wadi) dries up, there may be pockets of water remaining along its course (c.f.

oxbow lake An oxbow lake is a U-shaped lake or pool that forms when a wide meander of a river is cut off, creating a free-standing body of water. In South Texas, oxbows left by the Rio Grande are called '' resacas''. In Australia, oxbow lakes are cal ...

). In Western Sahara, gueltas correspond to

oases In ecology, an oasis (; ) is a fertile area of a desert or semi-desert environmentGuelta d'Archei in

Chad Chad (; ar, تشاد , ; french: Tchad, ), officially the Republic of Chad, '; ) is a landlocked country at the crossroads of North and Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Repub ...

and Timia in

Niger ) , official_languages = , languages_type = National languagesBillabong Billabong ( ) is an Australian term for an oxbow lake, an isolated pond left behind after a river changes course. Billabongs are usually formed when the path of a creek or river changes, leaving the former branch with a dead end. As a result ...

- term for a similar type of body of water in Australia Aquatic ecology Bodies of water Geomorphology Oases Wadis Wetlands {{geomorph-stub