Wednesday, October 5, 2011

THE THAR DESERT

The origin of the Thar desert is a controversial subject. Some consider it to be only 4000 to 10,000 years old, whereas others state that aridity started in this region much earlier. Also known as The Great Indian Desert, it is spread over four states in India, namely Punjab, Haryana, Rajasthan, and Gujarat, and two states in Pakistan and covers an area of about 4,46,000 square kilometres.
The average annual rainfall of the region varies from 100 to 500 mm, it is distributed very erratically, occurring mostly between July and September. The mean average temperature varies from a minimum of 24 degrees C to 26 degrees C in summer to 4 degrees C to 10 degrees C in winter. One unique feature of this desert is that there is neither an oasis in it nor any artesian well. No native cactus or palm tree breaks the monotony of the vast expanse.
Stretches of sand in the desert are interspersed by hillocks and sandy and gravel plains. Due to the diversified habitat, the vegetation and animal life in this arid region is very rich. About 23 species of lizard and 25 species of snakes are found here and several of them are endemic to the region.
Some wildlife species, which are fast vanishing in other parts of India, are found in the desert in large numbers such as the great Indian bustard, the black buck, the Indian gazelle, and the wild ass in the Rann of Kutch. How these animals and insects survive in these harsh conditions, under such high temperature and without drinking water and green vegetation is amazing. They have evolved excellent survival strategies, their size is smaller than other similar animals living in different conditions, and they are mainly nocturnal. There are certain other factors responsible for the survival of these animals in the desert. Due to the lack of water in this region, transformation of the grasslands into cropland has been very slow.The protection provided to them by a local community, the Bishnois is also a factor.
The increase of human and livestock population in the desert has lead to a deterioration in the ecosystem resulting in degradation of soil fertility and vegetation.

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