Write a short note on the Indian Desert.
The Thar desert: This Indian Desert lies towards the western margins of the Aravalli Hills. It is a sandy plain and considered to be the hottest region in the country in daytime but nights are cold. The region receives scanty rainfall which is usually less than 25 cm. Rainfall, whatever it is, occurs in the months of July and August. Luni is the only notable river in the region. Barchans (crescent-shaped sand dunes) largely cover the area.