Question
Describe the landforms formed by the action of wind deposition.
Solution
The following landforms are formed due to the wind deposition:
1. Sand dunes: Sand dunes are hills of wind-blown sand. These are found in the areas like sandy coasts in deserts, on the sandy shores of lakes and along river banks.
The sand dunes are formed in following conditions:
i. Large supply of sand, ii. Strong winds, iii. Obstruction in the way of wind.
Sand is deposited at the base of an obstruction such as bushes and gradually a large amount of sand is deposited. Sand is thrown on the windward side by the strong winds. Thus a sand dune is formed with a crest. It has a long gentle windward slope and a steep leeward slope with ripple marks.
Sand dunes are of three types:
a. Longitudinal dunes: These are long narrow ridges of sand. These are called silts in Sahara.
b. Transverse dunes: These are formed perpendicular to the wind direction. They look like waves of sand. They are semi-circular in shape.
c. Barchans: Barchans are crescent or moon-shaped sand dunes formed in a perpendicular direction to the wind. The windward side is convex and gentle while the leeward side is steep. Its ends are called horns. These resemble a sickle or bow. The sand-dunes keep on advancing and many towns and buildings have been burried under these sand dunes.
