The largest desert in the world. The largest Sahara desert the largest desert in the world

1. Sugar. 9,065,000 sq. km.

The Sahara Desert is the largest in the world, with an area of over 9 million square meters. km .. It covers almost all of North Africa: Egypt, Algeria, Tunisia, Morocco, Mauritania, Sudan, Chad, Libya, etc.
The name "Sahara" is an Arabic translation of the Tuareg word for "desert" In summer, the air temperature can rise to 58 °, in winter it is kept within 15-28 ° C.

In the Sahara, as in other sandy deserts, sandstorms are frequent, strong winds can carry sand dust even to Europe.
More than 150 thousand mirages are observed in the Sahara, which are marked on maps indicating which mirage is most often "shown" in this particular area - an oasis, a river or a well.

There is less rainfall in the south of the Sahara than in the north, there are especially dry periods lasting up to three years, during which there is no rain at all. The only source of water in the Sahara besides rain is the Nile, which crosses it in the east. However, thanks to underground waters in the arid desert, there are oases with deep wells; it is in the oases that hotels for tourists who come to drive around the Sahara in jeeps are located; the most luxurious date palms and sweet grapes grow in the oases.

2. Arabian Desert. 2,330,000 sq. km.

The Arabian Desert is located on the Arabian Peninsula, located in Saudi Arabia, Egypt, occupies part of Iraq, Syria, southern and eastern Jordan. The vast expanses of the Arabian Desert are occupied by moving sand dunes and massifs of sand, in its center is Rub 'al-Kali, one of the largest massifs of sand in the world. Much of the territory is uninhabited due to frequent sand and dust storms and strong winds. high temperatures with large daily amplitudes usual for deserts. Temperature range - 40-50 ° C in summer, average temperature in winter - 5-15 ° C, although it can drop to 0 ° C.

Most of the desert is occupied by rubble, sandstone and limestone plateaus (khamadi), rising stepwise from west to east. In the east, along the coast of the Red Sea, the Etbay crystalline ridge stretches up to 2000 meters in height. In winter, episodic precipitation falls on its eastern slopes, which caused violent runoff in the usually dry river beds of the valleys. The underground runoff that persists throughout the year supports sparse grass and shrub vegetation and individual trees in the valleys. There were no oases in the 19th-20th centuries, but there were springs and natural cisterns filled with the water of winter rains.

In the mountains of the desert, the ancient Egyptians mined aphanite, diorite and other stones for sarcophagi and sphinxes. Then, in Mount Jebel Dukhan near the Red Sea, the Romans and Greeks mined red porphyry for making vases, busts, etc. end of XIX For centuries, granite, copper, emeralds were mined in the mountains. At the end of the 20th century, the population was mainly nomadic livestock breeders, oil and phosphorites were being extracted on the coast of the Red Sea.

3. Gobi. 1,166,000 sq. km.

The Gobi is located in Central Asia, on the territory of Mongolia and China, stretching from the Altai and Tien Shan mountains in the east to the North China plateau in the west; in the north, the Gobi passes into the steppe on the territory of Mongolia, in the south it is bounded by the Yellow River. The word "gobi" is of Mongolian origin and means "a dry place", this word in Central Asia means generally desert and semi-desert places. In aggregate, the Gobi desert is the largest desert in Asia.

The Gobi territory, raised above sea level to an altitude of about 2000-1000 meters, is the most sharply continental place on the planet. The air temperature in summer rises to plus 40 ° С, and in winter it drops to minus 40 ° С. The landscape of the Trans-Altai, Dzungarian, East Mongolian Gobi is diverse, it is not only a waterless and barren area with a sandy plain and high hilly dunes. Despite the arid climate, the desert contains crystal clear water sources and rich animal world... Most of it is occupied by vast flowering steppe plains, picturesque rocky mountains, clayey and stony hamadas, vast hollows with rare oases, hummocks, salt marshes, takyrs, dried gravel saury and long green saxaul groves. The entire landscape resembles African savannas, therefore, sometimes the areas where the Haylas are spread are called Gobi savannas. There are few sands in the Gobi, dune sands occupy only 3% of its territory, but clay and rocky deserts - hamadas - occupy vast areas.

4. Australian desert. 647,000 sq. km.

Deserts got a huge territory of Australia, almost half of the continent. Much of the Australian deserts to the west are located on a huge plateau 200 m above sea level. Some deserts rise even higher, up to 600 m. Difficult relief divides the giant Australian desert into several autonomous ones. The largest of them, the Great Sandy Desert, is located in the northwestern part of the continent, and the vast Great Victoria Desert stretches to the south. In the northern part of the Great Sandy Desert, the sands are red-brown in color, other areas are covered not with sand, but with dark gravel and pebbles.
Among the sandy deserts, the largest is the Arunta Desert, or the Simpson Desert. It is located in the central part of the continent, closer to the west.

5. Kalahari. 600,000 sq. km.

The Kalahari Desert, the largest of the deserts South Africa, covers an area of about 600 thousand square meters. km and is located in Botswana, South Africa and Namibia. The Kalahari Desert occupies the southwestern part of the hollow of the same name, located at an altitude of 900 m. In the west, the Kalahari edge lies at an altitude of 1500 m above sea level, in the east - even higher; the most low point the desert is located at an altitude of 840 m above sea level. The Kalahari surface is composed of horizontally lying continental strata of sandstones, pebbles and breccias.

Recently, the desert has expanded its boundaries and invaded Angola, Zimbabwe and Zambia. Precipitation (up to 500 mm) is confined to the summer period (November - April), but their value varies considerably both in time and in area. The Kalahari is one of the hottest regions in South Africa. The average maximum temperature is plus 29 °, and the average minimum temperature is plus 12 °.

6. Karakum Desert. 350,000 sq. km.

Karakum desert in the south Central Asia, occupies more than 80% of the entire territory of Turkmenistan.
The Karakum in Turkmen means "black sand" (from the Turkic "kara" - black and "kum" - sand. " species of mammals and about three dozen species of birds, plants - about 270 species.

Turkmenbashi's plans were to replace the ugly desert with a beautiful forest, planting trees in some areas, and it was also planned to build a zoo for penguins on its territory, which would attract visitors from all over the world. Fortunately, after the death of the Father of all Turkmens, nothing has been heard about these plans.

Sahara 9,065,000 km²

The largest desert in the world, with an area of about 9,065,000 km² - slightly less than the area of the United States of America. Sahara is located in North Africa, on the territory of more than ten states (Egypt, Libya, Tunisia, Algeria, Morocco, West Sahara, Mauritania, Mali, Niger, Chad, Sudan). The Sahara defies categorization within one type of desert, although the sandy-rocky type is predominant.
In the Sahara, about 160 thousand mirages are observed annually ( optical phenomenon in the atmosphere: reflection of light by the boundary between layers of air that are sharply different in density. For the observer, such a reflection consists in the fact that, together with a distant object (or a part of the sky), its imaginary image, displaced relative to the object, is visible.). They are stable and wandering, vertical and horizontal. Even special maps of caravan routes have been compiled with an assessment of the places where mirages are usually observed ..

Arabian Desert... 2,330,000 km²

The Arabian Desert is located on the Arabian Peninsula, is located in Saudi Arabia, Egypt, occupies part of Iraq, Syria, southern and eastern Jordan. The vast expanses of the Arabian Desert are occupied by moving sand dunes and massifs of sand, in its center is Rub 'al-Kali, one of the largest sand massifs in the world. Much of the territory is uninhabited due to frequent sand and dust storms and strong winds, high temperatures with usual for deserts with large daily amplitudes.The temperature range is 40-50 ° C in summer, the average temperature in winter is 5-15 ° C, although it can drop to 0 ° C.

Gobi... 1,166,000 km²

A vast region in Central Asia (in the territories of Mongolia and China), characterized by desert and semi-desert landscapes. The Gobi stretches from the Altai and Tien Shan mountains in the east to the North China plateau in the west; in the north, the Gobi passes into the steppes of Mongolia; in the south, the region is bounded by the Nanshan and Altintag mountains and the Yellow River. The Gobi comprise several geographic regions: Trans-Altai Gobi, Mongolian Gobi, Alashan Gobi, Gashun Gobi and Dzungar Gobi. The word "gobi" is of Mongolian origin and means "waterless place"; this word in Central Asia means generally desert and semi-desert landscapes. In aggregate, the Gobi desert is the largest desert in Asia.

Australian desert... 647,000 km²

simpson desert

Great Sandy Desert

Kalahari... 600,000 km²

Desert in South Africa within the states of Botswana, South Africa and Namibia. Recently, by increasing the area, it invades the territory of Angola, Zimbabwe and Zambia. The Kalahari area is about 600 thousand km2. The Kalahari climate is arid with a summer maximum precipitation and mild winters, with aridity increasing towards the southeast. Precipitation (up to 500 mm) is confined to the summer period (November - April), but their value varies considerably both in time and in area. The Kalahari is one of the hottest regions in South Africa. The average maximum temperature is plus 29 °, and the average minimum temperature is plus 12 °

Karakum... 350,000 km²

Sandy desert in the south of Central Asia, covering most of Turkmenistan. The area is 350,000 km². The desert includes the Zaunguz Karakum, Central Karakum, Lowland Karakum and South-Eastern Karakum.

Chocolate candies are named after this desert.

Borders

Of course, a desert of this size could not cover the territory of one or two African countries... It captures Algeria, Egypt, Libya, Mauritania, Mali, Morocco, Niger, Sudan, Tunisia and Chad.

From the west, the Sahara is washed by the Atlantic Ocean, from the north it is bounded by the Atlas Mountains and the Mediterranean Sea, and from the east - by the Red Sea. The southern border of the desert is defined by the zone of inactive ancient sand dunes at 16 ° N, to the south of which the Sahel is located - a transitional region to the Sudanese savannah.

Regions

It is difficult to attribute the Sahara to any particular type of desert, although the sandy-rocky type predominates here. It includes the following regions: Tenere, Greater Eastern Erg, Greater Western Erg, Tanezruft, Hamada al-Hamra, Erg-Igidi, Erg-Shesh, Arabian, Algerian, Libyan, Nubian deserts, Talak desert.

Climate

The climate of the Sahara is unique and is determined by its location in the zone of high-altitude anticyclones, downdrafts and dry trade winds of the northern hemisphere. It rarely rains in the desert, and the air is dry and hot. The Sahara sky is cloudless, but it will not surprise travelers with blue transparency, since the finest dust is constantly in the air. Intense solar exposure and evaporation during the day gives way to strong radiation at night. At first, the sand heats up to 70 ° C, glows with heat from the rocks, and in the evening the surface of the Sahara cools much faster than air. The average July temperature is 35 °.

The high temperature, with its sharp fluctuations, and very dry air make being in the desert very difficult. Only from December to February comes the “Saharan winter” - a period with relatively cool weather. In winter, the temperature in Northern Sahara can drop below 0 ° at night, although it rises to 25 ° during the day. Sometimes it even snows here.

Desert nature

Bedouin walks the dunes

Despite the fact that the desert is usually represented by a continuous layer of hot sand forming dunes, the Sahara has a slightly different relief. In the center of the desert there are mountain ranges with a height of more than 3 km, but on the outskirts, pebble, stony, clay and sandy deserts have formed, in which there is practically no vegetation of any kind. It is there that nomads live, driving herds of camels across rare pastures.

Oasis

The vegetation of the Sahara consists of bushes, grasses and trees in the highlands and oases located along the river beds. Some plants are fully adapted to the harsh climate and grow for 3 days after rain and then sow seeds for 2 weeks. At the same time, only a small part of the desert is fertile - these areas take moisture from underground rivers.

The well-known one-humped camels, some of which were domesticated by nomads, still live in small herds, feeding on cactus thorns and parts of other desert plants. But these are not the only ungulates living in the desert. Pronghorns Addax, Maned Sheep, Dorcas Gazelles and Oryx Antelopes, whose curved horns are almost as long as their bodies, are also perfectly adapted to survive in such difficult conditions. The light color of the coat allows them not only to escape the heat during the day, but also not to freeze at night.

Several species of rodents, including the gerbil, the Abessinian hare, which comes to the surface only at dusk, and during the day hiding in burrows, the jerboa, which has surprisingly long legs, allowing it to move with huge leaps like a kangaroo.

The Sahara Desert is also home to predators, the largest of which is the fennec fox, a small chanterelle with wide ears. There are also dune cats, horned vipers and rattlesnakes, which leave winding tracks on the surface of the sand, and many other species of animals.

Video: From Casablanca to Sahara

Sahara in the cinema

The mesmerizing landscapes of the Sahara never cease to attract filmmakers. A lot of films were shot on the territory of Tunisia, and the creators of two famous films left a memory of themselves among the sands. The planet Tatooine is not actually lost in space, but is located in the Sahara. Here is a whole "extraterrestrial" village from the last series of "Star Wars". At the end of filming, the "aliens" left their homes, and now the quaint dwellings and gas station of interplanetary aircraft at the disposal of rare tourists. The white Arab house from The English Patient is still visible next to Tatooine. You can get here only by jeep and with an experienced guide, because you have to go off-road, in the complete absence of signs and landmarks. Fans of the "English Patient" need to hurry a little more and the ruthless dune will finally bury this unusual attraction under the sand.

Even from school, we know that the Sahara is the largest desert in Africa, and the rest of the world. We are used to presenting it in the form of endless sand dunes. In fact, in the Sahara, you can find high mountain ranges and volcanoes, salt marshes and relict lakes, lush oases and rocky deserts. Amazing Berber tribes live here, where matriarchy rules and men hide their faces under the "veil". The famous " star Wars And the Exupery plane crashed. But most importantly, scientists believe that the reasons for the formation of the Sahara Desert are technogenic in nature. We talk about all this in the article!

Location and geographic features

The Sahara occupies a third of the entire African continent. It is located in North Africa and stretches across the territory of ten states. The desert begins at the Atlas Mountains and the Mediterranean coast and lasts until the Sudanese savannah. From the west it is washed by the Atlantic Ocean, and from the east - by the Red Sea.

The relief of the Sahara is extremely diverse, and the height of the desert ranges from mountain ranges, towering 3000 meters above sea level, to depressions 133 meters deep. At the same time, the sands in the desert occupy only a quarter of its territory. The Nile flows in the east of the Sahara, and in the south there are several small rivers that feed Lake Chad, and the Niger River also flows.

Officially, the area of the desert is 8.6 million km². However, cattle grazing and deforestation lead to the fact that its territory increases by 6-10 km annually. Therefore, the World Wildlife Fund (WWF) estimates the actual area of the desert at 9.2 million km². In terms of its size, the Sahara already exceeds the territory of Brazil and is gradually being compared with the United States.

The most amazing thing is that the origin of the desert is the work of man! For millions of years, the savannah stretched across the territory of modern Sahara. North African elephants, extinct in the era of Ancient Rome, lions, rhinos and giraffes lived here. Crocodiles and hippos lived in the waters of many deep lakes, and cities and villages were built on their shores. In general, life in the future desert was in full swing, as evidenced by numerous excavations and preserved rock paintings.

However, about 5-8 thousand years ago, the tribes inhabiting North Africa began to switch to pastoralism. They raised cattle, sheep and goats. Uncontrolled grazing of large livestock led to the disappearance of vegetation in a particular area. As a result, the amount of sunlight reflected from the surface increased, and this led to a decrease in precipitation. As a result, the process of desertification began, and over several millennia from a flourishing and fertile region, North Africa turned into a huge desert.

Climate and air temperature

The Sahara can be roughly divided into two natural areas with different climates: northern subtropical and southern tropical. The subtropical part is characterized by hot summers and cold winters. In December-January, snow often falls in the mountains on the territory of the desert, and at night the soil even manages to freeze.

The most low temperature in the Sahara Desert was registered just in sub tropical zone and was -18 ° C. Daytime temperatures in winter usually hover around + 37 ° C. In summer, the temperature in the Sahara Desert rises above + 50 ° C, and the desert sands heat up to + 70 ° C. Daily temperature drops are significant here both in summer and winter. In the southern tropical zone, winters are not so cold, but summer temperatures are quite comparable.

As for the rains, they mostly fall in the desert from December to March. On average, up to 130 mm of precipitation falls per year in the south and up to 76 mm in the north. The relative humidity is 30-50%. At the same time, an increased evaporation rate is observed in the region (up to 6000 mm per year).

At the same time, impressive underground water resources are concentrated on the territory of the Sahara, including artesian waters. In those places where underground waters break through to the surface, oases appear. Also in the desert you can find rocky lakes "gelty", which fill up during the rains and do not dry up throughout the year, and relict salt lakes, preserved in the mountains from time immemorial.

One of the main attractions of the Sahara are wadis - dry beds of ancient rivers, which, during the rains, turn into real full-flowing rivers.

Plants and fauna of the Sahara

Despite the fact that the Sahara is considered a lifeless and hot desert, its fauna is surprisingly diverse. It is home to about 60 species of mammals, 300 species of birds, reptiles and protozoa. Large animals are usually found along the northern and southern borders of the desert. Antelopes, ostriches, jerboas, hares and hedgehogs are found here. Not without predators - foxes, hyenas, jackals and even cheetahs.

In the rocky and sandy parts, the main inhabitants of the desert are insects and reptiles. Here you can find lizards, monitor lizards, snakes and scorpions. Frogs, crustaceans and even crocodiles live in lakes and oases! Well, the main food for migratory birds among sand dunes is desert snails, which can hibernate for several years in anticipation of rain.

As for the flora, it is scarce throughout the desert. In oases mountainous regions and along the beds of the dry "wadi" rivers one can find olive trees, acacias, cypresses and palms. However, in most of the desert, there is either no vegetation at all, or it is a small accumulation of grasses and small shrubs.

Moreover, plants in the Sahara are maximally adapted to the local climate. For example, in many seemingly low shrubs and grasses, the root system can reach 15-20 meters in length, thereby reaching groundwater. Individual plants come to life during the rains, in just a couple of days they ripen and scatter their seeds. Well, in the oases, you can observe gorgeous vegetation. Olives, figs, citrus fruits and dates are often grown here.

Desert population

In those days, when the Sahara was a flourishing savannah, a large number of inhabitants lived on its territory. Basically, these were the Berber and Zaghawa tribes, who were engaged in cattle breeding and agriculture. Important trade routes connecting the Atlantic coast of Africa with the Middle East also passed through the Sahara. Later on these roads Islam penetrated and spread to the region. Nowadays, many desert dwellers practice this religion.

With the desertification of the region, people began to leave here. Only small groups of farmers remained to live in the territories of the oases. Cattle breeding became nomadic and consisted of a constant search for new pastures. Traders have also adapted to the changed climatic conditions- moved from horses to camels. Gradually, the number of desert inhabitants was replenished at the expense of the Berber and Arab tribes, who first hid here from the ancient Roman conquerors, and then from the spread of Islam. This is how the famous Tuaregs appeared among the peoples of the desert.

The Tuaregs are a nomadic tribe of Berber warriors. They live in the south of the desert on the territory of several countries at once: Mali, Niger, Libya, Algeria and Burkina Faso. The Tuaregs have long been engaged in trade and controlled the caravan routes laid in the desert, and also often conquered agricultural settlements in the oases. Now they mainly breed camels and goats, are engaged in agriculture and jewelry making.

Despite professing Islam, matriarchy reigns in Tuareg society. Women here do not hide their faces and learn to read and write without fail. Men, on the other hand, may remain illiterate, and after marriage they transfer to the wife's family. Upon reaching adulthood, young people are presented with a tagelmust headscarf - a turban with a veil. From this point on, a Tuareg man must hide his face in public.

Another amazing people of the desert is the Tubu tribe. Its representatives live in the Tibesti Highlands in Central Sahara, on the border of Chad, Libya and Niger. Hot and lifeless mountain plateau resembles a lunar surface. However, the tuba can pass through it up to 80-90 km per day, doing without food and water. Local wisdom says that a tuba needs only one date a day: he will eat the peel for breakfast, the pulp for lunch, and the bone for dinner. Indeed in better days their diet includes desert herb tea, a handful of millet and dates. At the same time, tuba are known for their longevity and extremely low infant mortality rate!

We used to think of the Sahara as a hot desert. However, there are floods here too! History remembers two similar disasters: in 1922 and in August 2018. Both floods occurred in the vicinity of the city of Tamanrasset in the south of Algeria. Heavy downpours caused dry riverbeds to overflow and streams of water spread across the desert, eroding roads and demolishing settlements.

There is really plenty of water in the Sahara! In the north-east of the desert is the world's largest underground source of fresh water - the Nubian Aquifer. In the 1970s, Libya began to extract fresh water here to irrigate crops. After that, a unique plumbing system called the "Great Underwater River" was built, with the help of which water is delivered to the arid northern regions of the country, the cities of Tripoli and Benghazi. This project was recognized as the largest waterworks in the world! Recently, Egypt has also joined in the extraction of water through the Nubian aquifer.

Nubian aquifer

Another fact that completely destroys the image of a deserted and useless desert territory is the presence in the Sahara large deposits mineral. Here, rich deposits of oil and gas, iron, copper, gold, tungsten, uranium and other rare metals have been discovered. In the north of Niger, table salt is also mined from clay.

The benefits of the Sahara are manifested not only in its depths. The desert has inspired many writers, filmmakers and musicians. Perhaps the most famous "inhabitant of the desert" was Antoine de Saint-Exupery. His acquaintance with the Sahara took place in 1926, when the young pilot was appointed commander of an intermediate postal airport in the desert in southwestern Morocco. Here he wrote his first work - the novel "Southern Postal".

Antoine de Saint-Exupery at the crashed plane in the Sahara

In 1935, Exupery decided to set a record on his own plane, flying from Paris to Saigon. However, over the Libyan Desert, one of the driest parts of the northeastern Sahara, his plane crashed. The pilot and his mechanic spent four days in the desert and nearly died of thirst. They were rescued by local Bedouins. This incident subsequently formed the basis of "The Little Prince".

Sahara also served as a filming location. In Tunisia, George Lucas filmed Star Wars. Then the "planet Tatooine" was built in the desert. It was 40 years ago. However, until now, due to the absence of rain and the remoteness of the place, the scenery is safe and sound. Another director who worked in the Sahara is Ridley Scott. He filmed The English Patient here.

A still from the movie "Star Wars". The planet Tatooine rebuilt in the Sahara

Sahara Desert Excursions

The best time to travel to the hot Sahara Desert is during the off-season. At this time, conditionally ideal weather is established here: the nights are not as cold as in December-January, and during the day it is not as mercilessly hot as in summer. V southern regions desert tourists prefer to travel in winter. However, whichever season you choose, you will have to take both light clothes for day walks and a warm sleeping bag for spending the night.

The territory of the Sahara covers ten African countries, however, due to the difficult political situation, it is unlikely that it will be possible to cross the entire desert. Now you can safely travel to Tunisia, Morocco, Egypt and Algeria. Tours to the Sahara depart from the main tourist destinations in these countries. Cities in the desert itself are usually small and located in oases.

And I would gladly write you letters,

About ten thousand years ago, the territory where the largest desert of our planet, the Sahara, is now located, was covered with grass, low bushes and was densely populated. After our planet slightly changed the inclination of its axis, the climate began to gradually change, it became hot, the rains stopped - and many representatives of the animal world left the formed desert.

The Sahara (in the translation from Arabic - "desert") is the largest desert on our planet, which is located in northern Africa and is located on the territory of ten states. On the geographic map it can be found at the following coordinates: 23 ° 4 ′ 47.03 ″ s. latitude, 12 ° 36 ′ 44.3 ″ E etc.

The Sahara occupies about thirty percent of the African continent, and its area is about 9 million km2:

From east to west, the length of the desert is 4,800 km: the Sahara begins off the coast Atlantic Ocean and ends off the coast of the Red Sea.
The length of the Sahara from south to north ranges from 800 to 1200 km. The desert begins in the north of the mainland, off the coast of the Mediterranean Sea and the Atlas Mountains, southern border limited to 16 ° N. sh., in the area of inactive ancient dunes, to the south of which begins the tropical Sahel savanna, a transitional territory between the desert and fertile soils of Sudan.

When exactly the Sahara desert was formed on the territory of the African continent, scientists do not have a unanimous opinion: earlier its age was estimated at 5.5 thousand years, then at four, recently they began to tend to the idea that it was even younger, and its lands became deserted only about three thousand years ago.

The desert is located in the northwest of a stable ancient African Platform, therefore, shuddering of the soil is rarely observed at the present time. In the center of the platform, the relief rises from west to east: one of the largest high-mountain regions of the desert are the Ahaggar and Tibesti plateaus, where, unlike other regions of the Sahara, snow falls briefly almost every year.

From the northern and southern parts of the uplifts - the deflections of the platform, where in the past there was a sea, and therefore the presence of marine sedimentary rocks is characteristic of the soil. In the south of the desert, the trough of the platform has led to the formation of large lakes, which are the main suppliers of fresh water for their region. First of all, we are talking about Lake Chad and the Unianga group of lakes.

Sands occupy only one fourth of the Sahara, while the thickness of the sandy layer is about 150 meters. Stony soil predominates: it occupies about 70% of the desert area, the rest is volcanic mountains, as well as pebble and sandy-pebble soil.

There are also many aquifers (sedimentary rocks with varying degrees of water permeability, the cracks and voids of which are filled with water), which are the main suppliers of water to the oases.

Sometimes fertile lands are found in the desert - mainly near oases that take water from underground rivers and reservoirs, the water of which, due to its own pressure, was able to reach the ground.

On the map of Africa, the Sahara is divided into several regions:

Western Sahara - located in northwest Africa, the territory is characterized by coastal lowlands, which turn into elevated basement plains and plateaus.
The central highlands of Ahaggar - on the map it is located in the south of Algeria, the highest point is Mount Tahat with a height of 2918 meters, so it often snows here in winter.
The Tibesti mountain plateau is located in the center of the desert, in the north of the state of Chad and partly in the south of Libya. Highest point the plateau is the volcano Emi-Kusi with a height of almost 3.5 km, on the top of which snow falls annually.
Desert Tenere - located in the south of the central Sahara. It is a sandy plain with an area of about 400 thousand km2, which is located in the northeastern part of Niger and in the west of Chad.
Libyan Desert - on the map of Africa, it is located in the north and is the driest region of the desert.

Climate

The Sahara is the hottest and hottest place on our planet: not even the driest desert in the world, the Atacama, located in South America, can compare with it.

The weather in summer is extremely hot here: air temperature at this time often exceeds 57 ° С, and the sands heat up to 80 ° С. At the same time, the Sahara Desert is one of the few places on our planet where evaporation significantly exceeds the amount of precipitation (with the exception of narrow coastal strips). While the average indicators of precipitation are only 100 mm (while in the center they may not be for several years in a row), from 2 to 5 thousand mm of moisture evaporates.

Conventionally, the Sahara can be divided into two climatic zones, northern (subtropical) and southern (tropical):

The northern part of the desert is characterized by hot summers (up to 58 ° C) and cold winters (especially cold weather in the mountains, where temperatures can drop to -18 ° C). The annual rainfall is 80 mm, rainy weather is here from December to March and in August, with frequent thunderstorms and even severe short-term floods. In winter, snow falls briefly on the high mountain plateaus Ahaggar and Tibesti almost every year.

The south is characterized by mild winters, and rains fall at the end of the hot and dry period. There is little precipitation in mountainous regions, and it goes evenly throughout the whole year. In the lowlands, it rains in the summer, often accompanied by thunderstorms, about 130 mm of precipitation falls per year. In the west, near the coast of the Atlantic Ocean, humidity is higher than in the rest of the Sahara, and there are often fogs here.

The difference between daytime and nighttime air temperatures in the Sahara is often about forty degrees: the average temperature in the center of the desert in July is 35 ° C, while at night the air temperature drops to + 10 or + 15 ° C. The weather here is also warm in winter: the temperature of the coldest month of the year is + 10 ° С (therefore, snow is an extremely rare phenomenon).

The climate of the Sahara is very strongly influenced by constantly blowing strong winds, especially in the north of the desert (only 20 days a year are calm). The winds blow mainly from north to east: the movement of the wet air masses Mediterranean air stops mountain range Atlas Mountains.

As for the air currents that move from the south, when they reach the central part of the desert, they have time to lose moisture, so the winds in the northern part of the desert are especially destructive. They move at a speed of about 50 m / s and, raising dust, sand, small stones to a height of more than a thousand meters, cause tornadoes and strong sandstorms, often moving the dunes.

Water resources

The only river North Africa that goes through eastern part Sahara towards the Mediterranean Sea is the Nile, which is 6,852 km long (the river is the second longest after the Amazon, and flows through South America).

Since a considerable part of the water evaporates as we move through the desert, its two tributaries, the White and Blue Nile, play an important role, which flow into it in the southeast of the desert (they are very clearly distinguishable on the map). In the 60s of the last century, the Nasser reservoir was created between Egypt and Sudan, the total area of which exceeds 5 thousand km2.

In the south of the Sahara, several river streams flow into Lake Chad, the area of which ranges from 27 to 50 thousand km2 (depending on precipitation in the region), after which part of the water leaves the lake - and the water continues to flow in a northeastern direction, replenishing watersheds.

In the southwest flows the Niger River, which flows into the Gulf of Guinea in the Atlantic Ocean. This river is interesting because it starts almost near the ocean, 240 km from the coast, it flows in the opposite direction, to the Sahara, after which it turns sharply to the right and continues its way in the southeast direction (the shape of the river, if you look at the map of Africa, resembles a boomerang).

In the northern part of the desert, water comes from wadi streams, temporary water flows that appear after heavy rains and flow down from the mountains. Also, wadis feed the soil of the desert in its central part. A lot of rainwater is in the dunes: once in the sand, water seeps down the slopes and flows down.

Under the sands of the desert there are huge pools of groundwater, thanks to which oases are formed (especially in the north of the Sahara, while in the south the aquifers are located deeper).

Another source of water in the largest desert of the planet is relict lakes (remnants of the former seas) located on the outskirts and in mountain ranges, often swampy and salty, although fresh ones are often found among them (for example, the water of most lakes of the Unianga group).

Flora

There is not much vegetation in the Sahara - mainly shrubs, herbs and trees that grow near a natural reservoir, along a wadi or in high-altitude regions, including olives, cypress, dates, thyme, citrus fruits.

In areas where water is scarce, there are only those types of vegetation that tolerate drought well. There are no plants at all in rocky massifs, in places of accumulation of sand.

Fauna

The desert is inhabited by almost 4 thousand representatives of the animal world, most of which are invertebrates. The animals of the Sahara Desert live mainly near the water (they are practically not found in arid regions) and are nocturnal.

Most of the animals are monitor lizards, cobras, lizards, chameleons, snails. Crocodiles, frogs, crustaceans are found in reservoirs. There are about sixty species of mammals, among them - cheetah, spotted hyena, sand fox, mongooses.

The Sahara is home to about 300 species of birds, 50% of them are migratory. These are primarily ostriches, African owl, trumpet and desert crows and others.

Desert and people

Despite its huge area, the desert is hardly inhabited: only 2.5 million people live here. Some peoples are nomadic, but most prefer to settle. People settle only near oases, as well as in the valleys of the Nile and Niger rivers, where, in order to survive on their own and feed livestock, there is enough water and vegetation. At the same time, breeding of cattle: goats and sheep prevails over fishing and hunting.