The desert of the Sahara Ecoregion , as defined by the World Wide Fund for Nature (WWF), includes the Sahara hyper-arid center, between 18 Â ° and 30 Â ° N. This is one of several deserts and xeric grove ecoregions that cover the northern part of the African continent.
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The Sahara Desert is the largest hot desert in the world, located in North Africa. It stretches from the Red Sea to the Atlantic Ocean. The vast desert covers several ecologically different areas. The Sahara Desert Ecoregion covers an area of ​​4,619,260 km 2 (1,783,510 sqÃ, mi) in the hot, hyper-dried centers of the Sahara, which are encircled in the north, south, east and west by the ecoregion desert with higher rainfall and more vegetation.
The lands of grasslands and the eco-equality of the northern Sahara forest lie to the north and west, bordering the Mediterranean climate regions of the Mediterranean of Africa and the North Atlantic coast. The North Sahara steppes and forests receive more regular winter rainfall than the Sahara desert glaciers. The South Saharan steppe and forest ekoregion lie to the south, between the desert Sahara desert and the Sahel meadow. The South Sahara steppes and forests receive most of their annual rainfall during the summer. The Red Sea coastal desert lies on the coastline between the Sahara desert ecoregions and the Red Sea.
Several mountains rose from the desert and received more rain and cooler temperatures. The Sahara Mountains are home to two different ecoregions; the western Sahara xeric forests of Ahaggar, Tassili n'Ajjer, AÃÆ'¯r, and other ranges in the western and central Sahara Desert, and Tibane-Jebel Uweinat montane xeric forests in Tibesti and Jebel Uweinat from the eastern Sahara.
The desert surface ranges from a large area of ​​sand dunes (erg), to high rocks (hamadas), gravel terrain (reg), dry valleys (wadi), and salt flats. The only permanent river that crosses the ecoregion is the Nile River, which originates from Central Africa and empties north to the Mediterranean Sea. Some areas include a vast underground aquifer that produces oases, while other areas are very short of water reserves.
Climate
The Sahara Desert has a hot desert climate (climatic classification KÃÆ'¶ppen BWh ). The Sahara Desert is one of the driest and hottest regions of the world, with an average temperature of sometimes over 30 ° C (86 ° F) and average high temperatures in summer over 40 ° C (104 Â ° F) for months at a time, and can even soar to 47 Â ° C (117 Â ° F). In rocky mountain deserts such as Tibesti in Libya or Hoggar in Algeria, the highest average in summer is moderated slightly by high elevation and between 35 and 42 Â ° C (95 and 108 Â ° F) at 1,000 to 1,500 meters (3,300 to 4,900 Ã, ft) elevation. Daily variations can also be extreme: swings from 37.5 to -0.5 ° C (100 to 31 ° F) have been observed. Typical temperature changes are between 15 and 20 Â ° C (27 and 36 Â ° F).
Rainfall in the Sahara Desert is rare, as the whole desert generally receives less than 100 millimeters (3.9 inches) of rain per year except in the northernmost and southernmost tip as well as in the highest desert mountains. More than half of the desert area is very barren and almost painless, with average annual rainfall below 50 millimeters (2.0 inches) and many years in a row can pass without rain. In the southern Sahara Desert, along the border with the semi-arid climate ( BSh ) of the Sahel, receives most of its annual rainfall during the highest solar months (summer) when the Inter Zone of the Tropical Convergence moves up from the south. Wind and sandstorms occur in early spring. Locals protect themselves from heat, sunlight, dry air, high diurnal temperatures and sometimes dusty or sandy winds covering their heads, such as the chech clothing worn by Tuareg.
Maps Sahara Desert (ecoregion)
History and preservation
The Sahara is one of Africa's first planted areas. About 5,000 years ago, the area was not so dry and the vegetation was probably closer to the savanna. Fauna could previously be recognized in stone carvings. However, desertification occurred about 3000 BC, and the area became as it is today.
The Sahara is largely undisturbed. Degradation is most prevalent in areas where there is water, such as the aquifer oasis or along the edge of the desert where rain usually falls most of the year. In these areas, animals such as addaxes, horned sword oryxes, and heroes are too hunted for their flesh. Only one conservation area is listed in the Sahara: Zellaf Nature Reserve in Libya.
References
Source of the article : Wikipedia
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