Deserts in the World - Part II

Deserts cover about one-seventh of the earth's land surface.

Deserts have been classified into
a)sub-tropical desert -lie between 15 and 30' latitude.
b) Cold winter
c) The cool coastal

->They are centered along the Tropics of Cancer and Capricorn.
->Deserts are landscape forms or regions that receive little precipitation.
->They are cold at night and since the desert air is dry it holds little moisture.

World desert can be subdivide into 4 based on the amount of total precipitation in a year.

i) Semiarid
ii) Arid
iii) Extremely arid
iv) Rainless deserts .

-> A desert is extremely dry with little or no vegetation, comprises of one of the major ecosystems on this planet.
->It supports a wide range of plant and animal species that are attuned to survive in the harsh conditions.
->Some plant do not have leaves, which helps them reduce loss of water, while others have long roots that help them fetch water from deep down the earth. Similarly, perennials and annuals have behavioral patterns that help them adapt to harsh conditions of the desert.
->Although some definitions of world desert also includes areas which are too cold to support any vegetation, such as frigid deserts.

Some of the most important deserts in the world are:

1) Sahara Desert: Sahara, the largest desert in the world, occupies an area of 8,600,000 sq km and comprises almost the whole of North Africa. Sahara desert is bounded on the west by the Atlantic Ocean; on the north by the Atlas range of mountains and the Mediterranean; on the east by the Red Sea; and on the south by a vast zone of unmoving sand dunes.

2) Arabian Desert: Occupying almost the whole of the Arabian Peninsula and covering an area of about 2,300,000 sq km, the desert is spread in Saudi Arabia. To its southwest is Yemen; Oman lies on its eastern edge; Jordan in the northwest; and the United Arab Emirates and Qatar form its northern limit along the southern coastline of the Persian Gulf.

3) Great Sandy Desert : A vast wasteland in North western Desert, the Great Sandy desert extends from Eighty Mile Beach on the Indian Ocean eastward into Northern Territory and from Kimberly Downs southward to the Tropic of Capricorn and the Gibson Desert.

4) Thar Desert: Occupying about 200,000 sq km, the Thar Desert is a vast tract of sand hills covering the Indian state of Rajasthan and parts of Pakistan. The barrenness of the area is mainly attributed to the dryness of the seasonal monsoon winds which do not bring enough rain to make the region moist and wet.

5) Simpson Desert: Occupying about 143,000 sq km, the Simpson Desert is in a largely uninhabited barren area of Central Australia, on the southeastern corner of the Northern Territory and includes parts of Queensland and South Australia. The desert is famous for its national parks and protected areas that are home to some of Australia's rare desert wildlife species. Sand-sliding skinks (a type of lizard), mouse-like marsupial - mulgara, spinifex hopping mouse, water-holding frog are the few animals of the desert Simpson.

6) Takla Makan Desert : A great desert of Central Asia and one of the world's largest sandy deserts, the Takla Makan covers an area of about 320,000 sq km in China's Xinjiang province.

7) Gobi Desert : Another of Central Asia's great and famous deserts , the Gobi is actually not much of a sandy desert but a vast stretch of arid land comprising mostly of bare rocks that occupy about 1,300,000 sq km of Mongolia and China.

8) Sonoran Desert : An arid region of North America, the Sonoran Desert occupies an area of 310,800 sq km and comprises southwestern Arizona and southeastern California in the United States; the Mexican state of Baja California; and the western part of the Mexican state of Sonora.

9) Kalahari Desert : Occupying about 930,000 sq km, the Kalahari comprises the whole of Botswana; the northern part of Northern Cape Province in South Africa; the eastern part of Namibia; and in the southwest merges with the Namib Desert.

10) Atacama Desert : The Atacama Desert is a 1,000 to 1,100 km long, cool and arid coastal strip in northern Chile, which extends southwards towards the border of Peru.

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