Dr. S.M. Alam
Feb 10 - 23, 2003



Sahara Desert, is a great desert area, lying in Northern Africa, and the western portion of the broad belt of arid land, extends from the Atlantic Ocean eastward past the Red Sea to Iraq.

BOUNDARIES: The boundaries of the Sahara are the Atlantic Ocean on the west, the Atlas Mountains and the Mediterranean Sea on the north, the Red Sea and Egypt on the east, and the Sudan and the valley of the Niger River on the south. The boundaries, however, are not clearly defined and have been shifting for millennia. Most of the desert's interior averages less than an inch of rainfall a year.

HISTORY: The Sahara was once a fertile area, millet was cultivated there over 8000 years ago. As conditions gradually became drier, however, and desertification set in, farmers abandoned their land. the Sahara bounds with tales of larger disasters overtaking even the most seasonal and desertwise wayfares. In 1805, for example an entire caravan of 2,000 men and 1,800 camels perished of thirst in the desert's south-central wastes, because water holes along their route had gone dry.

PHYSICAL & GEOGRAPHICAL STRUCTURE: The entire Sahara Desert is the largest Desert in the world, Sahara Desert is about 1610 km (about 1000 miles) wide and about 5150 km (about 3200 miles) long from east to west. The total area of the Sahara is more than 9,065,000 sq. km (more than 3,500,000 sq. miles), of which some 207,200 sq. km (some 80,000 sq. miles) consist of partially fertile oasis. Only a tenth of its total area is in dunes. It is home to over three million people, has mountains 10,000 ft. high and a lake as big as New Jersey. Sahara Desert geographically consisted of the following regions: First are the western Sahara, which is sometimes called the Sahara proper; second comes the central Ahaggar Mountains about 11,500 ft. high and the Tibesti massif, a plateau region; and finally the third one is the Libyan Desert in the east. They are as follows:



i) The western Sahara is an area of rock-strewn plains and sand deserts of varying elevation. The land is almost entirely wlthout rainfall or surface water but possesses a number of underground rivers that flow from the Atlas and other mountains. Occasionally the waters of these rivers find their way to the surface; in these naturally irrigated oasis, plants grow freely. The soil of this region of the Sahara is fertile and, where irrigation is possible, produces excellent crops. Road gang and oil-field workers in this Sahara get a daily allotment of two gallons of water per man for drinking and cooking alone.

ii) The central plateau region of the Sahara runs for approximately 1610 km (approximately 1000 miles) in a northwestern to southeastern direction. The plateau itself varies in height from about 580 to 760 m (about 1900 to 2500 ft), and peaks in the several mountain ranges that rise from the plateau are from about 1830 to more than 3414 m (about 6000 to more than 11,200 ft high). Notable peaks include Emi Koussi (3415 m/11,204 ft), in the Tibesti massif, and Tahat 3003m/9852 ft, in the Aliaggar range. Although, rainfall is scanty in the area, a number of the central Saharan peaks are snowcapped during part of the year.

iii) The Libyan Desert is considered the most arid part of the Sahara. Moisture is almost totally absent and few oasis exist. The land is characterized by sandy wastes and large dunes of sand 122 m (400 ft) or more in height The valley of the Nile River and the mountainous area of the Nubian Desert to the east of the Nile are, geographically, a part of the Sahara, but the irrigation afforded by the Nile transforms the desert into fertile agricultural land throughout much of Egypt.

FACTS ABOUT SAHARA DESERT (VEGETATION, CLIMATE, ECONOMY): The Sahara as a whole is a tableland with an average elevation from about 400 to 500 m (about 1300 to 1600 ft). Only comparatively small areas are elevated as little as 150 m (500 ft) above sea level. The climate is uniformly dry; most areas average less than 127 mm (less than 5 inches) of rain per year, and some get none at all for years at a time. The temperature range is extreme, ranging between freezing to more than 54.4 C (130 F) in the western and central portions. Except in the oasis the desert is almost devoid of vegetation, although some stunted, thorny shrubs grow in the western Sahara. Artificial oasis have been created by drilling water wells more than 1000 m (more than 3280 ft) deep. The Saharan climate has probably changed not once but a number of tunes in recent geologic periods from 60,000 to 6,000 B.C. It was wet, many of the river beds, now so dust-dry, ran full and some of the vast plains, now so barren, were covered with forests that surged with life.

VEGETATION: The chief trees of the oasis are the date palm and a form of acacia.

ANIMALS: (lazelle and antelope are found in many parts of the desert, as are jackal, fox, badger, and hyena. The Libyan Desert is virtually devoid of any form of animal or vegetable life.

ECONOMICAL IMPORTANCE: The northern Sahara has assumed economic importance with the discovery of extensive petroleum deposits in Algeria and Libya.

COUNTRIES: The Countries which fall in the Sahara Range are mainly Morocco, Algeria, Tunisia, Libya, Egypt, Mauritania, Mali, Niger, Chad, and Sudan.