barchan

barchan
/bahr kahn"/, n.
a crescent-shaped sand dune with the convex side in the direction of the wind.
[1885-90; < Russ barkhán, said to be < Turkic]

* * *

also spelled  Barkhan,  

      crescent-shaped sand dune produced by the action of wind predominately from one direction. One of the commonest types of dunes, it occurs in sandy deserts all over the world.

      Barchans are convex facing the wind, with the horns of the crescent pointing downwind and marking the lateral advancement of the sand. These dunes are markedly asymmetrical in cross section, with a gentle slope facing toward the wind and a much steeper slope, known as the slip face, facing away from the wind. Barchans may be 9–30 m (30–100 feet) high and 370 m (1,214 feet) wide at the base measured perpendicular to the wind. They gradually migrate with the wind as a result of erosion on the windward side and deposition on the leeward side. The rate of migration ranges from about a metre to a hundred metres per year. Barchans usually occur as groups of isolated dunes and may form chains that extend across a plain in the direction of the prevailing wind.

      Barchans are characteristic of open, inland desert regions such as Turkistan, where the name originated. The Russian naturalist Alexander von Middendorf is credited with introducing the word into scientific literature in 1881.

* * *


Universalium. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • Barchan —   [turkmenisch] der, s/ e, Sicheldüne, Bogendüne, halbmondförmige Wanderdüne, aerodynamisch günstige Form mit flachem Anstieg auf der Luvseite und halbkreisförmig eingebuchtetem Steilhang im Lee. (Dünen) * * * Bar|chan, der; s, e [russ. barhan,… …   Universal-Lexikon

  • barchan — {{/stl 13}}{{stl 8}}rz. mnż I, D. u, Mc. barchannie {{/stl 8}}{{stl 7}} tkanina bawełniana, z jednej strony włochata, używana do szycia bielizny <arab.> {{/stl 7}} …   Langenscheidt Polski wyjaśnień

  • barchan — [bär kän′, bär′kän΄] n. [Russ barkhan] a crescent shaped sand dune formed in certain inland desert regions, with the convex side facing into the wind …   English World dictionary

  • Barchan — A barchan dune is an arc shaped sand ridge, comprising well sorted sand. This type of dune possesses two horns that face downwind, with the slip face (the downwind slope) at the angle of repose, or approximately 32 degrees. The upwind side is… …   Wikipedia

  • Barchan — Düne im Sossusvlei (Namibia) Düne mit aufgesetzten Rippeln in Marokko …   Deutsch Wikipedia

  • Barchan — Bar|chan [... ça:n] der; s, e <aus turkotat. barchán »Wanderdüne«> bogenförmige Binnendüne (Geogr.) …   Das große Fremdwörterbuch

  • barchan — I m IV, D. u, Ms. barchannie; lm M. y «tkanina bawełniana, lewostronnie drapana, używana na ciepłą bieliznę, szlafroki, sukienki dziecinne» Gruby, kolorowy barchan. Kaftanik z barchanu. ‹ar.› II m IV, D. u, Ms. barchannie; lm M. y geol. «wydma… …   Słownik języka polskiego

  • barchan dune —    A crescent shaped dune with tips extending leeward (downwind), making this side concave and the windward (upwind) side convex. Barchan dunes tend to be arranged in chains extending in the dominant wind direction.    Compare: parabolic dune.… …   Glossary of landform and geologic terms

  • Barchan-Katze — margarita statusas T sritis zoologija | vardynas taksono rangas rūšis atitikmenys: lot. Felis margarita angl. dune cat; sand cat vok. Barchan Katze; Sandkatze rus. барханная кошка; барханный кот; песчаный кот pranc. chat des sables ryšiai:… …   Žinduolių pavadinimų žodynas

  • barchan — noun Etymology: Russian barkhan, from Kazakh Date: 1888 a moving crescent shaped sand dune …   New Collegiate Dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”