The Great Sahara Desert is located in Northern Africa and partially or completely covers the territory of almost eleven countries. This is the largest desert in the world, covering an area of more than 9,000,000 square meters. km, quite comparable to the area of the United States. It extends 1600 km wide and about 5000 km long from east to west. They say that a thousand years ago the climate in the desert was more humid. The fact is that in the distant past the territory of the Sahara was subjected to various atmospheric changes, which led to a change in climatic conditions. The desert divides the African continent into two parts - North and Sub-Saharan Africa. After reviewing the following interesting facts, you will learn more about this desert.
The Sahara Desert is the second largest desert in the world (after Antactis) and the largest hot desert planets.
It covers almost all parts North Africa. Extends from the Red Sea, including sections Mediterranean coast, to the edge of the Atlantic Ocean. In the southern region, its border is the semi-arid savannah region of the Sahel, separating the desert from Sub-Saharan Africa. However, the boundaries of the desert are not clearly defined; moreover, over the past thousand years they have undergone significant changes.
The Sahara passes through the territory following countries: Algeria, Chad, Egypt, Libya, Morocco, Mauritania, Mali, Niger, Sudan, Tunisia, Western Sahara.
The history of the desert goes back at least 3 million years.
The climate of the Sahara is combined: in the north it is subtropical, and in the south it is tropical.
The relief is quite varied, but in general it is a plateau lying at an altitude of 400-500 m above sea level. There are underground rivers here, which sometimes flow to the surface, forming oases. Vegetation develops well in such natural oases. The soil in these regions of the Sahara is very fertile, so where irrigation is possible, excellent crops grow.
Part of the desert territory is occupied by sand dunes that reach a height of 180 meters.
The central region is more elevated above sea level compared to the rest of its regions. The central plateau stretches for 1600 km from northwest to southeast. Its height ranges from 600 to 750 m, some peaks reach a level of 1800 m and even 3400 m. The highest points are the peaks of Emi Koussi with a height of 3415 m, Tahat - 3003 m, the Tibetsi massif and Ahaggar Highlands.
This may seem strange, but winter time There are snow caps on the mountain peaks. In the eastern part of the Sahara - the Libyan Desert - the climate is the driest, so there are very few oases here. This part contains sandy areas with large dunes, the height of which reaches 122 meters or more.
The climate of the Sahara Desert is very hot and dry. It gets very hot here during the day and cool at night.
The Sahara region receives only 20 cm of precipitation per year. It is for this reason that very few people live here. a large number of population, only 2 million people.
The desert used to be fertile land where elephants, giraffes and other animals grazed. Gradually it became increasingly arid, and the fertile landscape turned into the barren region we know it today.
The central part of the Sahara is extremely dry, with sparse or no vegetation. In areas where moisture accumulates, grasslands, desert shrubs, trees and tall shrubs are sometimes found here.
During the last ice age the desert was larger than it is now, extending south beyond its present boundaries.
Climatic conditions here are considered the toughest in the world. Prevailing northeasterly winds often cause sandstorms and micro-tornadoes called “dust devils.”
Arabic is the most widely spoken language in the Sahara, from the Atlantic to the Red Sea.
The Sahara is divided into several regions: Western Sahara, Central Highlands of Ahaggar, Tibesti Mountains, Aïr Mountains (a region of desert mountains and high plateaus), the Tenere Desert and the Libyan Desert (the driest region).
The Nile River Valley and the mountainous regions of the Nubian Desert east of the Nile are geographically part of the Sahara Desert. However, the waters of the Nile transformed this area of Egypt from a barren desert into a fertile agricultural area.
A truly endless sea of sand, stone and clay, with only rare green patches of oases and a single river - this is the Sahara Desert. Its territory is eight million square kilometers. That's bigger than Australia and slightly smaller than Brazil! Five thousand kilometers of heat and sand, from the Atlantic coast of Africa to the Red Sea. The origin of the great Sahara Desert holds many secrets and mysteries.
Scientists have conducted computer simulations of the Earth's climate. Research has shown the following:
- the desert exists on the site of the ancient Tethys Ocean, which existed during the Mesozoic era eleven million years ago (the remnants of this ocean are the Mediterranean, Black and Caspian Seas).
- During the Paleolithic period (10-12 thousand years ago), the climate in North Africa was much more humid. The Sahara was not a desert, but a steppe-savannah.
- about 5–7 thousand years ago, a drought began, the land of the Sahara began to lose more and more moisture, and the grasses dried out.
Whale skeleton in the Sahara Desert
The photo shows the remains of a 15-meter beast that died thirty-seven million years ago and sank to the bottom of the ancient Tethys Ocean. And in Egypt there is the Valley of the Whales, included in the list of “ World Heritage UNESCO".
There is one in the situation with these remains in the desert important point— the average rate of soil level growth, according to official studies, is 1-2 mm per year. Over 37 million years, several tens of kilometers should have accumulated, but these bones lie on the surface. And not only in the Sahara, there are such remains on the surface of other deserts, in the Gobi (Mongolia), Atacama (Chile). How did they end up on the surface - they were probably brought by the same flood, which happened relatively recently - only 10 thousand ago.
The Sahara Desert is not entirely covered with sand. But we are presented with an image of this desert: continuous sands, dunes with rare rocky massifs.
But there is still a lot of sand - where does it come from?! Moving forward different versions:
- The classic one assumes that the sand is from the Tethys Ocean. But it’s not clear why there was so much sand at the bottom of the ocean
- There is a version that sand is the result of technological processing of rocks. V. Kondratov expresses this version and connects it with aliens who needed it for some reason
- I found a completely plausible version related to the action of flood waves. More details here:
Little-known landscapes of the Sahara Desert
Chad. 16° 52′ 24.00″ N 21° 35′ 31.00″ E
Egyptian desert
All these are remnants of the pristine surface. They look like islands. The rest of the territory may not have been so strong; the flood carried away the rest of the soil when the waves passed through the continent. The washed away soil is the sands of the Sahara. Soil, rocks, washed by water erosion of the flow of grains of sand to grains of sand.
In general, not all of the Sahara is “yellow”. There is a White Desert in its eastern part. It is full of oddly shaped remains, covered with sand white, which gives it the appearance of the Arctic north, there are also many karst deposits and caves.
Rather, here the waters of the ocean retreated gradually, and organic traces of the ocean were largely preserved here.
The Sahara Desert and life in it
The fact that the territory of the Sahara Desert was once inhabited and actively used is also evidenced by numerous rock paintings found in different parts of it. During the years when glaciers raged in the north, the population of the Sahara was engaged in cattle breeding and agriculture, as well as hunting and even fishing. 
Somewhere in the middle of the second millennium BC, outlines of chariots drawn by horses appear on the rocks. The image of a horse on the rocks of the Sahara can be traced back to the 2nd century AD.
Also, one of the most common subjects of Sahara rock paintings is this image mysterious creatures, which many researchers mistake for gods, ancient astronauts or aliens.
Despite popular belief, the Sahara Desert on the map is not the largest in the world. In fact, in terms of area it is inferior Ant arctic desert, but among hot deserts and located on inhabited continents, the Sahara is the undisputed leader.
Sahara Desert on the map of the world and Africa
The Sahara is the greatest desert in the world, not in size, but in influence on history and modern life person. Humanity lived in the Sahara many millennia ago, as evidenced by more than 3 thousand rock paintings in various parts deserts.
And now the Sahara has a huge impact on the political, economic and cultural life North Africa.
Because of their huge The size of the Sahara is distinguished by a fairly diverse climate, soil type, living conditions and local inhabitants - from Arabs in the north to black peoples in the south of the desert.
What continent is it on?
Sahara is located in the northern part African continent and extends from the coast in the north to tropical savannas Sahel in the south at 16° N. sh., from the coast of the Atlantic Ocean in the west to the east of the continent.
Which country does it belong to?
The following African states are located entirely or partially on the territory of the Sahara:
- Libya;
- Tunisia;
- Algeria;
- West Sahara;
- Mauritania;
- Mali;
- Niger;
- Chad;
- Sudan.
History and names
Scientists believe that even in 5-4 millennium BC e. trees grew in the Sahara, earth's surface was covered with grasses and shrubs, and water resources were represented by numerous lakes.
Presumably, complex desertification began at the same time due to a decrease in moisture and the predominance of moisture evaporation over precipitation.
Reason this could be like natural factors(climate change), and the anthropogenic factor - the transition of local tribes to a pastoral type of animal husbandry, which led to desertification. On the other hand, such a transition could be caused by the transformation of once flourishing savannas into desert.
Be that as it may, in about a thousand years The Sahara turned into a desert, and the desertification process was completed by the middle of the 3rd millennium BC. e.
The name Sahara presumably comes from the Arabic word "ṣaḥārā", which means "desert". Another possible origin of the name is from the Arabic “sahra”, which means “red-brown”. The name of the desert has been fixed since the 1st century AD. e. after Arabic-speaking tribes reached the Sahara.
If your acquaintance with the Sahara is accompanied by a vacation in Tunisia, then find out what weather in the country by month.
Climatic conditions
Climate of the Sahara - deserted(arid), characteristic feature which is the predominance of evaporation processes over humidification processes.
The southern part of the desert has dry tropical climate with hot summers and mild winters. The amount of precipitation per year is usually about 130 mm. In winter, at night the air temperature can drop below zero, and in summer it often reaches +50°C.
Northern part desert has dry subtropical climate with hot summers and relatively cold winters. The average air temperature in summer reaches +37°C, and in winter in mountainous areas it can drop to -18°C. This part of the desert is characterized by high daily fluctuations in air temperature due to night cooling. The average annual precipitation does not exceed 75 mm.
Sand Sea - what is it like?
Sahara - active desert, which annually increases its area, moving southward by 10 km.
Characteristics of endless sands
About a quarter of Sugar consists of sand dunes, a quarter - from mountains of volcanic origin, and half from barren rocky plains and cliffs. The area of the territory with stable vegetation does not exceed several percent.
One of the reasons for the dryness of the Sahara is the presence of the Atlas Mountains in the north of the desert, which block the access of humid Mediterranean air to the Sahara.
The central part of the Sahara, where the least amount of annual precipitation(no more than 20 mm per year) is one of the most lifeless places on Earth. The average amount of biomass in this part of the desert drops to 2 kg/ha or less.
Square The desert covers almost 9 million km², which is equal to almost 30% of the territory of Africa. The desert stretches for 4.8 thousand km from west to east and 1.2 thousand km from north to south.
Water sources in the Sahara are:
- artesian groundwater, above the surface of which there are oases;
- rainwater, which fills gelts (ponds or natural puddles) and wadis (dry beds of ancient rivers filled with rainwater);
- large rivers on the outskirts of the desert (Nile, Niger).
Flora and fauna
A significant part of the desert has no vegetation at all and is classic sand. Plants that are mostly resistant to arid climates grow in oases and high-altitude areas (grass, small shrubs and trees). Various varieties are grown in oases cultivated plants : dates, olives, figs, vegetables.
Fauna Sugars are mainly represented various types rodents and reptiles, as well as birds, more than half of which are migratory. Large mammals include antelopes, rams, and the Nubian donkey. Predators: spotted hyena and cheetah. Most of Sahara animals are active at night, when the heat is not so great.
For those wishing to visit deeper places in the Sahara, it is recommended to get to erga Shigaga- a conglomerate of sand dunes in the heart of the Moroccan Sahara. There is a tent camp here, where tourists can expect all the benefits of civilization available in the desert.
Picturesque Shigaga, whose dimensions are 30 by 15 km, exceeds any expectations: countless untouched dunes, practically devoid of vegetation, stretch to the end of the horizon.
Another popular route in the Moroccan part of the Sahara is a trip to Ergu Chebbi through the village of Merzouga. Erg Chebbi is as colorful as Shigagu, but getting to it is a little more difficult.
Mauritania
Mauritania is located almost entirely within the Sahara, but travel here is rarity due to the poverty of the local population, lack of infrastructure and quite high level crime in the country.
For those who decide to tour this exotic country, it will be interesting to visit Adrar plateau, in which the UNESCO World Heritage sites are located - the villages of Ouadan and Chinguetti. On the plateau itself, despite its lifelessness, there are more than 20 large oases, including quite Big City Atar.
Algeria
Algeria is a country with greatest The territory of the Sahara in its composition, more than 80% of the country's area is occupied by desert.
The most stunning desert landscapes are located in the south-eastern part of Algeria at the foot of the Tassile Mountains.
Tassil Plateau- one of the objects of the UNESCO list; the oldest petroglyphs, whose age ranges from 2 to 9 thousand years, were found in local caves.
Others man-made attractions Algerian part of the Sahara are:
- Ouargla city;
- Mzab Valley with fortified cities.
These settlements are of great value from a historical and architectural point of view and were founded and developed in the 10th century Ibadis- a branch of Muslims distinct from Sunnis and Shiites.
Of the natural attractions of the Algerian part of the Sahara, it stands out Ahaggar Highlands in the south of Algeria, consisting of volcanic remains of bizarre shapes. Open on site national park Ahaggar, and the guides of tourists are local residents Tuaregs, whose unique culture will be interesting for any tourist.
Geographical position. Tropical deserts occupy a vast territory in northern Africa. Desert and semi-desert landscapes extend from the Atlantic Ocean to the Red Sea, from the foothills of the Atlas Mountains and the Mediterranean coast to a line running roughly from the lower reaches of the Senegal River through Lake Chad to Khartoum on the Nile (see map of the physiographic zoning of Africa with links to photographs of the nature of this region). This huge space with an area of about 7 million km 2 is united under a common geographical name- Sugar.
The geographical boundaries of the Sahara are quite defined. Only in the south. where natural conditions change more or less gradually from semi-deserts to savannas, the physiographic boundary is somewhat blurred and separates areas with a pronounced rainy season.
Geological structure. Most of the Sahara is a plateau, composed of crystalline and volcanic rocks at the base and overlain by strata of horizontal sedimentary deposits. In some places, an ancient folded foundation protrudes to the surface, forming high highlands, or ancient intrusions emerge in the form of dome-shaped hills.
In the extreme east, between the Red Sea and the Nile, the crystalline basement is uplifted and in places overlain by layers of Mesozoic sandstone. There rise table plateaus up to 2000 m high, intersected by deep dry gorges, indicating strong erosional dissection in the previous wetter era. This part of the region is known as the Arabian and Nubian deserts.
West of the Nile stretches the plateau of the Libyan Desert with the greatest accumulations of sand in the world. In the north, the surface of the Sahara gradually decreases, with some deep depressions located below sea level. The Qattara Depression, with an absolute bottom elevation of 133 m below sea level, is one of the deepest dry depressions on Earth.
In the central part of the Sahara, high highlands and plateaus rise, composed of crystalline and volcanic rocks: the Tibesti, Ahaggar, Iforas highlands, etc. highest peak Tibesti highlands - dormant volcano Emi-Kusi (3415 m) with a crater with a diameter of 12 km; it is the highest peak in the Sahara. The relief of the massifs is highly dissected, their slopes are steep and rocky, and masses of coarse clastic material have accumulated at the foot.
The surface of the rest of the Sahara, with prevailing altitudes of 300-400 m, is covered with strata of limestone, sandstone and clayey rocks of various ages.
Relief. Many areas of the Sahara have a monoclinal structure and form well-defined cuesta scarps. This type of relief is typical for the Tassilin-Adjer plateau, bordering the Ahaggar highlands from the northeast, for the Tademait plateau located to the north and the Bani plateau adjacent to the Anti-Atlas, etc. In the formation of the cuesta relief of the Sahara, the role of tectonics and erosion processes, which manifested themselves in the post-glacial period, is great. wetter than the modern era.
The surface of the desert plateaus of the Sahara is crossed by a network of channels bearing the Arabic name “wedd”, or “wadi”. Only after rare rains do they fill with water, which dries up after a few days, and sometimes after a few hours. Most of the water diverges radially along the slopes of the central Sahara massifs, which served as watersheds during the pluvial period, when a network of erosional depressions in the Sahara formed. Their bottoms are currently covered with alluvial sandy material, and sometimes they represent a hard clay surface.
Many wadis end in closed depressions of various sizes and depths, which are also one of the features of the Sahara topography. After rains, the depressions are filled with water for a short time. The bottoms of some depressions (sebkhs) are covered with a crust of salts, but those that have underground drainage are usually not saline. The origin of the depressions is determined by tectonics, underground erosion processes, karst processes and the blowing out of weathering products.
With the high intensity of weathering processes and the absence of removal, clastic material accumulated in huge quantities in the Sahara. Some parts of the desert, especially the depressions between cuesta plateaus and vast closed basins, are characterized by huge accumulations of dune sand, the so-called ergs. Along with areas of motionless, “dead” sands large areas occupied by sand dunes constantly moving in the direction prevailing winds. Particularly powerful accumulations of sand have been noted in the Libyan Desert. The relative height of the dunes there reaches 300 m. In the Sahara, there are often vast flat areas with a layer of pebble material, sometimes covered with sand (“reg” or “serir”) on the surface. Large spaces are cluttered with rubble formed as a result of the destruction of crystalline rocks. Such rocky deserts are called “hamada”. Among the rubble accumulations of Hamads, isolated plateaus with steep rocky slopes rise - “gara”.
Climatic conditions. The continental Sahara deserts owe their existence to the dominance of dry tropical air throughout the year. The climate of most of it is sharply continental, the annual precipitation almost everywhere is less than 50 mm (Fig. 114).
Rice. 114. Annual variation of temperatures, precipitation and relative humidity in the Algerian Sahara
In inland areas there is sometimes no precipitation for several years in a row and rainfall is random. However, sometimes heavy rains cause floods. Known to have drowned in the Sahara more people than died from the heat. Caravan routes usually passed along the bottoms of dry riverbeds, and people did not have time to escape from sudden heavy rains.
A slight increase in precipitation is observed only on the slopes of high uplands, but even there the annual amount does not reach 100 mm. On the northern and southern edges of the desert, more constant precipitation is confined to certain periods of the year. In the north they fall in autumn, winter and spring, and in the south in summer. These bands of more or less constant rainfall serve as a transition from the Sahara to the Atlas country in the north and the Sudan natural region in the south. The air in the Sahara is always dry and full of dust; relative humidity it is very small, sometimes below 25%. On hot days, with strong and uneven heating of the air, visibility conditions can be distorted, mirages appear with non-existent rivers, lakes or mountains on the horizon. Along with low precipitation, the Sahara has the highest evaporation rate in the world. Over the course of a year, a layer of water up to 6 m thick can evaporate in this hot desert. Strong winds increase evaporation. The most constant summer winds are the trade winds, which carry dry and hot air from the north and northeast. Atmospheric depressions that occur in summer cause severe sand and dust storms- one of the main disasters in the Sahara.
Temperature variations are characterized by sharp daily and annual contrasts. IN summer time the heat reaches 30...50 °C, it is aggravated by constant hot and dry winds carrying dust and sand. The absolute maximum of 58 °C, observed in the Sahara in the shade, is the absolute maximum for the entire Earth. The soil surface heats up to 60... 80 °C. In summer, even at night, the temperature usually does not drop below 30 °C, but daily fluctuations of 30...50 °C are possible.
IN winter months the air is cooler and more stable as anticyclonic weather sets in. During the day, the temperature stays around 20...25 °C; at night, due to strong heat transfer, the air cools to 0 °C, and sometimes there are such severe frosts that water in vessels and artificial reservoirs freezes. Frosts down to -18 °C were observed in the mountains.
The western edge of the Sahara, located off the coast of the Atlantic Ocean with its cold Canary Current, is a different type of desert - coastal. Due to the proximity of the ocean, temperatures become more moderate, relative humidity reaches 75-80%, refreshing breezes blow on the coast, but there is little more rain than in the interior of the Sahara.
Natural water. There is almost no surface water in the Sahara; the source of water supply is groundwater, on the proximity of which the existence of people, animals and plants depends. Sandy deserts are richest in underground water. In some places, quite thick horizons lie under the sand. groundwater, giving rise to sources. Sub-channel watercourses are characteristic of many wadis. Water in the Sahara is mostly taken from wells. Recently, deep artesian wells and wells, equipped with pumps that pump out the most reliable and permanent water from pressure horizons, have begun to play a significant role in water supply. There is evidence of huge reserves artesian waters in the depths of the Sahara and other areas of North Africa.
In the outlying parts of the Sahara and some mountainous regions there are lakes with clear water, preserved from the time of the last pluvial and fed by groundwater.
The only major permanent watercourse within the region is the Nile. This river, flowing for many hundreds of kilometers through the barren desert and bringing it to life, is one of the most remarkable natural phenomena in Africa. But the Nile's existence is supported by the waters it receives outside the desert.
Vegetation. The soils of the Sahara do not form a continuous cover. Vast areas of sandy and rocky deserts are almost completely devoid of soil. However, when the land is irrigated, the Sahara can become very fertile, as it contains many salts necessary for plants. But rising groundwater levels are often associated with excess salinization and the appearance of salt marshes.
IN vegetation cover There are 1,200 plant species that contain sugars. The vast majority of them are xerophytes or ephemerals. Only relatively few areas, mostly rocky, seem completely lifeless. But even on them there are plants that are amazing in their ability to adapt to the harsh conditions of the desert. For example, among the stones or on the sand you can find the rose of Jericho - a plant with a short stem and branches bent like fingers with seeds clutched. When it rains, the branches unclench, the seeds fall to the ground and germinate very quickly, using every drop of moisture. Seeds or tubers of other plants are stored in the ground and also germinate quickly after rains that occur every few months or even several years. In some places, on sand and rocks, there are thorny, squat or creeping plants with small leaves or spines. Sometimes the stones are covered with a thick crust of lichens. In some places there are tree-like spurges. The vegetation cover is dominated by gray-green, gray and yellow tones, which gives it a particularly sad, lifeless appearance.
U southern border Communities of shrubs and some tough grasses appear in the sugars. In the north, along the border with the Atlas Mountains, there are wild pistachios, oleanders and jujubes.
Animal world. Poor in species, but quite rich in individuals, the fauna of the Sahara includes animals that are hardy and move quickly in search of water and food, or constantly live near water sources. The most typical species for the Sahara are addax and oryx antelopes, Dorcas gazelle, dama gazelle, and mountain goats. They are hunted for their meat and skins, some of which have almost disappeared.
The most famous predators are jackals, hyenas, foxes, and cheetahs. There are birds, both migratory and permanent. Among the latter, the desert raven is especially characteristic. Of the reptiles, lizards predominate; snakes and turtles are found. Rare bodies of water in strictly localized habitats have preserved relics of pluvial eras - crocodiles.
The existence of relict fauna, as well as many other facts (for example, dry erosion depressions, terraces on the slopes of lake depressions) indicate that in the recent geological past the climate of the Sahara was wetter than it is now. Particularly convincing are the rock paintings discovered in the caves of the Central Sahara massifs depicting plants and animals that are now absent from the Sahara, hunting scenes, etc. It is assumed that during the last pluvial, i.e. 10-15 thousand years ago, the Sahara was watered and quite densely populated.
Population and environmental problems. The modern population of the Sahara is concentrated mainly in oases. Oases are one of the attractions of the Sahara, green spots among vast desert spaces. They occur where there is water on or close to the surface. In some oases, water is taken from springs that sometimes feed small rivers, in others - from wells. The largest oases in the Sahara are formed near artesian wells. Many of them exist for a relatively short time and then disappear if the source dries up or the well dries up. But there are oases dating back hundreds and even thousands of years. The largest and most ancient oasis of the Sahara is the Nile Valley, irrigated by Nile water and representing one of the oldest centers of agricultural culture.
As in the oases of South-West Asia, the main cultivated plant of the Saharan oases is the date palm, in the shade of which fruit trees and shrubs are grown and cereals are sown. Some oases have no permanent population; Arabs come there only at certain times of the year to collect dates. Noting the close connection date palm with the Sahara, some scientists consider it possible to draw the border of the Sahara as a geographical region along the border of the distribution of the date palm.
On the outskirts of the Sahara, some Berber-Arab tribes lead a nomadic or semi-nomadic lifestyle, breeding camels and sheep. They live in large tents and dress in loose, long clothes that protect their bodies from overheating.
In some areas of the Sahara, salt has long been mined and exported, and iron and other metals have been smelted. But the real use of natural resources in the Sahara countries is just beginning. And the riches of this desert territory are incalculable, first of all its mineral reserves. After World War II, large oil and gas deposits were discovered in Libya, Algeria and other countries. There are also large reserves of iron, manganese, copper ores, uranium.
Great amount solar energy, which the surface of the Sahara receives, represents inexhaustible possibilities for agriculture; soils contain many nutrient minerals. Mention has already been made of the supposed huge reserves groundwater, which allow the use of climate and land resources of the Sahara.
In the decades since the formation of independent states in North Africa, paved roads have been built across the Sahara, new cities and towns have sprung up in mining areas, and the number of people engaged in agriculture has increased. But these essentially positive processes in the conditions of the extremely vulnerable nature of the Sahara also entailed undesirable phenomena. Currently, the area of deserts in northern Africa is increasing. The observed process of desert advance to the south, towards savannahs, is proceeding very quickly. Trampling the soil by livestock, burning and cutting down shrubs and trees along the desert border contribute to the destruction soil cover, fluttering sands and drying out water bodies.
Deserts have always attracted the attention of researchers and travelers. These are unique natural areas excite the imagination and frighten us with their mystery. The most famous desert in the world is the Sahara. In this article we will tell you how the Sahara Desert differs from other arid places on our planet and why it is interesting to modern science.
Geography of the Sahara Desert
The Sahara Desert is located in the northern part of the African continent and occupies almost 30% of the total area of Africa, which is comparable to the territory of Brazil. The area of the Sahara is about 8.5 million square kilometers, which is why this desert is called the “Great Sahara”. The Sahara is second only to the Arctic desert in size, but is the largest hot desert in the world. In the depths of the desert there is a huge amount of oil and natural gas. Especially in the territory belonging to Algeria and Libya. In addition, Algeria and Mauritania have large reserves iron ore, and Morocco has a large amount of phosphates.
The exact age of the desert is unknown. There are different versions on this matter. Initially it was believed that it was about 6 thousand years old. Now scientists agree that the Sahara was formed approximately 3.5 thousand years ago.
The Sahara Desert is washed Atlantic Ocean in the west, the Mediterranean Sea in the north, and the Red Sea in the east. The Niger River flows in the south of the desert.
The Sahara is located on the territory of 11 countries: Libya, Algeria, Egypt, Tunisia, Chad, Morocco, Eritrea, Niger, Mauritania, Mali, Sudan. Sometimes the disputed territory of Western Sahara is added to this list.
Sahara desert map
Relief of the Sahara Desert
Most of the Sahara is sandy, poor in organic matter, open spaces - flat pebble, clay and rocky plains. But here you can also find mountain ranges, plateaus, shallow basins, large oasis depressions and grasslands, which makes the relief of the Sahara quite atypical and varied. The most hilly part of the desert is its central region. It is here that the highest point of the Sahara is located - the Emi-Kousi volcano, 3,500 m high, and Mount Takhat, 3,003 m.
25% of the desert surface (almost 2.5 million km2) is occupied by wadis - sun-dried river beds and sand dunes. Dunes are found mainly in the north central region, in Algeria and Libya, where they are moved by strong winds. The wind moves the sand up the back slope of the dunes until it reaches the crest, whereupon it falls under the influence of gravity, cascading down the sliding surface. The wind builds dunes in the form of waves along its path. There are dunes of the Sahara different forms: round, star-shaped, crescent-shaped, transverse and pyramidal (up to 300 m high).
Sand dunes of the Sahara.
Sahara desert climate
The climate of the Sahara is one of the harshest in the world. There is little rainfall here and the wind blows strong winds, there are wide fluctuations in air temperature every day. The Sahara Desert is located in subtropical latitudes, with predominant zones of high atmospheric pressure, which obstruct the flow of moist air from the ocean.
There are two main climatic zones in the Sahara: in the north there are subtropics, and in the south there are dry tropics. The northern part of the desert is the driest, and the western part is the wettest. During the rainy season, only 2 cm of precipitation falls in the north. The rest of the desert can receive up to 9.9 cm of precipitation in a whole year.
The prevailing wind blows from the northeast towards the equator, which explains the aridity of the desert. The Sahara experiences very strong winds, up to 100 km per hour. They are called Siroko. Such winds can cause sandstorms, which can be seen even from space.
In the summer in the Sahara you can safely record temperature records, since the air heats up to +60 degrees Celsius, and the sand up to +80 degrees Celsius. On September 13, 1922, in the Libyan city of Al-Azizia, it was recorded Maximum temperature air in the Sahara - 57.7 degrees Celsius. Average annual temperature in the Sahara 30 degrees Celsius. Since the air contains little moisture to retain heat, there are large differences between day and night temperatures - up to 40 degrees Celsius.
In winter, in the northern part of the desert there may be negative temperatures. V last years ceased to be a rare occurrence.
Water in the Sahara Desert
The Sahara Desert has only two permanent rivers and a few lakes, but it has significant underground reservoirs and aquifers.
The permanent rivers are the Nile and Niger. The Nile originates in central Africa, south of the Sahara, and flows north through Sudan and Egypt and into the Mediterranean Sea. Niger flows into West Africa, southwest of the Sahara, and continues its journey northeast to Mali, deep into the desert, through Nigeria, emptying into the Gulf of Guinea.
There are about 20 lakes in the Sahara and only one of them contains drinking water. This is a shallow Lake Chad, which constantly expands and contracts. Lake Chad is located on the territory of the state of the same name, on the southernmost edge of the Sahara. In other lakes the water is very salty and not suitable for human consumption.
An oasis in the middle of the Sahara Desert
Saharan reservoirs often lie just below dry river beds and river valleys, called "wadi". Aquifers sometimes release some of their reserves to the surface. This is how oases arise. They can usually be found in lowest points relief depressions. For many desert residents, oases are the only source of life in the middle of a hot sandy ocean.
Population of the Sahara
The Sahara is home to just over two million people. These are people who live in permanent communities near water sources, as well as nomadic tribes. Because of climate change number of people, as well as many species of flora and fauna of the Sahara for last decade decreased sharply.
Animals and plants of the Sahara Desert
Quite poor and monotonous. Due to the specific climate, only 500 plant species are counted in this vast region. In particular, these are trees, grasses, thorny bushes, and palm trees adapted to very hot conditions and salt water.
Plants often grow around oases, lakes and on hills. In oases, people practice growing fruits and some vegetables. Along Atlantic coast Enough moisture falls for the growth of lichens, succulents, and shrubs. Tibesti and Jebel Uweinat meet in the highlands. Because temperatures are cooler, plants such as tamarix, myrtle, oleander, acacia and palms can be found in this region.
The Sahara Desert is inhabited by about 4 thousand representatives of the animal world. These are mainly invertebrates, about 15% of them are endemic. Animals of the Sahara are characterized by a nocturnal lifestyle and semi-aquatic habitat. The ponds are inhabited by crocodiles, frogs and crayfish. It is impossible not to mention lizards, scorpions, monitor lizards, chameleons and various reptiles that live on rocky slopes and sand dunes.
Almost 60 species of mammals are found in the Sahara. The most famous among them are the cheetah, the wild dog, some species of foxes (fennec fox, pale fox) and antelope, the spotted hyena and the Ethiopian hedgehog. Some animals are considered long extinct, such as the North African elephant and addax antelope, Saharan oryx, African wild dog and African lion. More than 300 bird species have been spotted in the desert. For example, silver-billed finch and masked amaranth.
The indigenous people of North Africa, the Berbers, raise camels, goats, sheep and donkeys.
The Sahara Desert is an attractive region for hunters. Due to intensive safaris, many animals are classified as vulnerable. For example, the Nubian ibex, which, like other representatives of the fauna, occupies an important place in the ecosystem.
Environmental problems of the Sahara Desert
Unfortunately, anthropogenic factors and here they played far from positive role. Due to the cutting down of trees, already scarce water bodies are catastrophically drying up. Animal grazing has led to the erosion of previously fertile soils. All this adds up to the fact that every year the desert becomes wider by 5-10 square kilometers. Due to the increase in desert area, the Earth's atmosphere is warming up faster, which negatively affects the inhabitants of the African continent and those who live beyond its borders.
Although very little research has been done in the desert region, it is clear that many animals and plants are dying out, although the reasons for this are not fully known.
Positive changes have been observed since 2014, as this year was officially dedicated to the problems of deserts and desertification. Thanks to this about serious environmental problems the whole world thought. Some states have taken over wide range commitments to preserve the Sahara. For example, a reserve was created in Niger, in which measures are being taken to protect and increase the populations of gazelles and antelopes living in the Sahara.
Interesting facts about the Sahara Desert
- Sahrawis are primarily of Berber and/or Arab origin.
- Because of impressive size The desert is also called the “Great Sahara”. The word “Sahara” itself means “greatest desert” in Arabic.
- Goats and camels are the most common domestic animals in the Sahara.
- In the desert, on natural rocks, archaeologists have found many rock paintings.
- Modern methods of mapping and measurement show that the desert changes its size from year to year, depending on the amount of precipitation in the region.
- Berbers, as well as Arab nomads, led their camel caravans across the Sahara, trading goods such as cloth, salt, gold and fish.
- Scientists predict that the desert will turn green again in about 15,000 years.
- The Sahara Desert is 70% gravel and 30% sand.
- The Marathon des Sables is held in the Sahara. Daredevils from all over the world can take part in the six-day race. This pleasure is not cheap and requires good physical preparation.
Sahara Desert for tourists
Although the Sahara Desert is strongly associated with an environment unsuitable for life, it is still of considerable tourist interest. You can get there from Tunisia, Egypt and Morocco. In other countries there are certain political problems that will make it difficult to stay there.
When going on an unconventional trip, it is extremely important to remember safety measures. Berber guides will play an invaluable role in exploring these vast expanses of sand. Without them, the Sahara Desert can be an extremely dangerous place to live.
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