Gateway to the Sahara
Welcome in Douz, town (and also oasis) known as „Gateway to the Sahara“.
The town of Douz has grown up around a large palm oasis that stands on the northern fringe of the Sahara. Surrounded by little other than desert and dry scrub land, historically it was an important stop on the trans-Saharan caravan routes. Today, it is destination for tourists who are interested in seeing the desert, and a starting point for desert treks by camel, motorcycle, or four-wheel-drive vehicle.
Douz is a major palm oasis and as such a large producer of "diglat noor" dates.
From the Atlantic Ocean in the west, the greater Sahara stretches across Africa to the Red Sea and down to the highlands of Ethiopia, encompassing an area ??????? km2. This ecoregion covers the central Sahara Desert, between 18° and 30° N, and has an area of 4,619,260 km2. The northern and southern margins of the Sahara receive more rainfalland have greater vegetation cover.
The surface of the desert ranges from large areas of sand dunes (erg Chech, Raoui), to stone plateaus (hamadas), gravel plains (reg), dry valleys (?????), and salt flats. Several deeply dissected mountain massifs (Ahaggar, Tassili N'Ajjer, Tibesti, and Aïr) rise from the desert areas, and are delineated as separate ecoregions. Vast underground aquifers that underlie much of the region sometimes penetrate the surface, resulting in oases.
The Sahara is located in a climatic divide. The Intercontinental Convergence Zone moves up from the south, but stops before the center of the Sahara, and consequently hardly carries any rain. Similarly, the winter rainfall of North Africa does not reach far south enough to regularly bring rain to the central Sahara. Consequently, the rainfall, albeit extremely rare, can fall in any season. The annual rainfall is below 25 mm, and in the eastern part of the desert it is less than 5 mm per annum. The scarcity of rainfall in this ecoregion is aggravated by its irregularity, as no rain may fall for many years in some areas, followed by a single intense thunderstorm.
The Sahara is one of the hottest regions in the world, with mean annual temperatures exceeding 30°C. In the hottest months, temperatures can rise over 50°C, and temperatures can fall below freezing in the winter. A single daily variation of -0.5°C to 37.5°C has been recorded. The Sahara is also extremely windy.
Hot, dust-filled winds create dust devils which can make the temperatures seem even hotter.
The extreme aridity of this area is a relatively recent feature. Much larger areas of the Sahara had adequate water only 5000 to 6000 years ago. It is not clear how much of this ecoregion was covered with vegetation, but in other parts of the Sahara the vegetation was closer to the savanna woodlands of eastern and southern Africa. Currently the ecoregion is in a "hyper arid" phase, with high summer temperatures, lower winter temperatures and rainfalll between 0 and 25 mm per annum.
Precambrian rocks are exposed in few places across the Sahara. During the Mezoic much of North Africa was under water and marine deposits were deposited. The area was uplifted in the Middle Tertiary and has been erodingever since. Shifting sands and bare rocks cover only about one-fifth of the greater Sahara. More than half of the area comprises soils known as yermosols, with shallow profiles over gravel or pebble beds. These soils have been developing over the past 50 million years.
The Sahara is a vast area of largely undisturbed habitat, principally sand and rock, but with small areas of permanent vegetation. The most degradation is found where there is water (oases, etc). Here, habitats may be heavily alteredby human activities. Previously existing tree cover has often been removed for fuel and fodder by nomadic pastoralists and traders.
The Sahara desert is not well protected. Yet, this may be due to the low population and impracticality of defining borders over this vast area. Fewer than 2 million inhabitants reside throughout the entire Sahara Desert. The majority are nomads, predominantly the Tuareg, Tibbu, and Moors. They survive by nomadic pastoralism, hunting, and trading. Most of these people are found in the desert margins and they do not often spend much time in the central hyper-arid portion.
At given coordinates you find Key to Sahara , your task is :
a) To take a picture of you and this key BUT you have to at picture too!
b) What special „parking“ is near given coordinates?
c) What is area of Sahara desert?
d) Dry walley is called……
e) For desert is specific sand. Try to describe sand particles range at this place. (sand is like ..... )
f) Desert creates special stones. (local tradesman offer them a lot) What is name of these unique stones.
a, b,e - Google will not help