Question

Barkhan is a _______.
 A. Crescent-shaped sand dune
 B. Circle-shaped dune
 C. Rectangle-shaped dune
 D. Glacial erosional feature

Answer 1

Hint: Barkhans are produced by the action of wind in one direction. They are created in the desert when huge amounts of sands are complemented by the supply of steady wind from one direction. The change in the direction of the wind and the amounts of sands determine the shapes of the sand dune.

Complete answer:
Crescent-shaped sand dune: Barkhans constitute a crescent-shaped sand dune. The term was coined in 1881 by Russian naturalist Alexander von Middendorf. Barkhans are spelled synonymously with barchans, these crescent-shaped sand dunes are created by the direction of continuous wind coming from one side. Barchan’s convex side is towards the direction of the wind. In India, they are commonly found in That desert, Rajasthan.
Circle-shaped dune: Circle-shaped dunes are rare and they are also known as oval or dome dunes. They form at the end of the crescentic dunes. Their average height is relatively lower than the rest of the dunes. They are found in the Taklamakan, a desert in northwestern China.
Rectangle-shaped dune: No literature is available on the rectangle-shaped sand dunes.
Glacial erosional features: Barkhans are characteristic of deserts and not glaciers. U-shaped valleys, glaciated valleys, hanging valleys, and aries are consequences of glacial erosions. They are formed by the features and sediments as residual materials of the glacier retreats. India’s largest glaciers are the Karakoram range, examples of U Shaped valleys are Ladakh, North-Western Indian Himalayas.
So, the correct answer is Option A.

Note: These barchans are arc-shaped, asymmetrical, along with a gentle slope towards the wind sand ridge. They are common landforms, particularly deserts all over the world. The word ‘Barchan’ has an Arabic origin.