Which of the following statements regarding Barchan is/are correct ?

Which of the following statements regarding Barchan is/are correct ?

  • 1. It is a crescent shaped mound of sand, which is deposited by the wind blowing constantly from one direction in a desert.
  • 2. The windward side has a convex steep slope with maximum height at the centre.
  • 3. Two ends of Barchan are called horns and point opposite to the direction the wind blows.

Select the answer using the code given below :

1 only
1 and 2 only
2 and 3 only
1, 2 and 3
This question was previously asked in
UPSC NDA-1 – 2024
Statement 1 is correct. A Barchan is indeed a crescent-shaped sand dune formed by wind blowing predominantly from one direction in a desert environment.
Barchans are one of the most common types of sand dunes. Their shape is a direct result of unidirectional wind flow and limited sand supply.
Statement 2 is incorrect. The windward side of a barchan dune has a gentle, convex slope where sand is pushed up by the wind. The leeward side, also known as the slip face, has a much steeper, concave slope (close to the angle of repose for sand, around 30-34 degrees) where sand avalanches down. The maximum height is at the crest, just before the slip face.
Statement 3 is incorrect. The two ends of the crescent shape are called horns. These horns point downwind, in the direction that the wind is blowing, because the sand moves faster around the edges of the dune than at the center. They point *in* the direction of the wind flow, not opposite to it.
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