- What caused the emergence of the Sahara
- Sahara climate
- Water sources
- Flora and fauna of the Sahara Desert
- Video
Sahara is the largest sandy desert on Earth. Its name comes from the Arabic word "sakhra", which in translation means "desert" (although some sources claim that it is translated from ancient Arabic as "red-brown"). The Sahara Desert is located in the northern part of the African continent and occupies almost a third of its entire territory - more than 9 million square meters. kilometers. The western outskirts of this geographic giant are washed by the Atlantic Ocean, and the eastern ones by the waters of the Red Sea.
According to scientists, from a geographical point of view, this part of Africa became a desert in its present form quite recently - only about four thousand years ago. Prior to that, its significant area was distinguished by a favorable climate and fertile soils, due to which there were many ancient civilizations on this territory, which left the descendants of the richest historical and cultural heritage. The most famous of these is Ancient Egypt.
What caused the emergence of the Sahara
The opinions of climatologists, geographers and geophysicists on this matter are ambiguous. Someone "blames" the change in the angle of inclination of the earth's axis for this, and someone else - the active and reckless "development" activities of the representatives of the above-mentioned civilizations.
At the word "Sahara" many people think of barren and deserted spaces of sand waves, above which mirages appear from time to time in the hot air from the heat - almost everyone has heard about this phenomenon, although few have actually seen them. However, sands make up only about 25% of the Sahara's area, the rest of the space is occupied by rocky rocks and mountains of volcanic origin.
In territorial terms, the Sahara is a conglomerate of deserts with very different soil characteristics. These include:
- Western Sahara, which combines both lowlands and mountain plains.
- The Ahaggar Highlands, located in the south of Algeria. Its highest point is Mount Tahat (2918 m above sea level). In winter, you can even see snow on its top.
- The Tibesti Plateau is the central part of the Sahara Desert. It covers the south of Libya and the northern part of Chad. Emmi-Kusi volcano rises above it, the height of which is about three and a half kilometers. Here, winter snowfalls are a fairly systematic phenomenon.
- Tenere is a sandy "sea" that occupies the northern part of Niger and western Chad. Its area is approximately 400 sq. km.
- The Libyan Desert is a "heat pole" in the Sahara.
Sahara climate
The climate and temperature regime of most of the Sahara can hardly be considered favorable. Its characteristics depend on which of the two zones - subtropical or tropical - will be discussed. In the first (northern) summer period is characterized by extremely high temperatures (+ 58 ° C), while winters are not African-style cold (in the mountains, frosts reach -18 ° C). Southern tropical winters can only be called such.
The lowest temperature of this time of the year is + 10 ° C here. There is little rain in the mountains, but it is quite regular. And in the low-lying part of the Sahara, near the Atlantic coast, thunderstorms and fogs occur. The difference between daytime and nighttime temperatures in the Sahara reaches twenty degrees: from + 35 ° C during the day to + 15 ° C at night.
Winds blowing over the Sahara have a great influence on climatic factors. The movement of air masses usually goes from north to east. The penetration of moist Mediterranean air deep into the Sahara is hindered by the Atlas mountain range.
Water sources
The main sources of water in the Sahara Desert are the Nile River (in the eastern part), the Niger (in the southwest) and Lake Chad (in the south).
After rare but powerful downpours in the mountains of the Sahara, streams of rainwater - wadis - appear. They dry out quickly, but some of them, flowing down, accumulate and remain under a layer of sand. It is thanks to such hidden water "lenses" that oases are formed in the desert.
Also, the composition of the water resources of the Sahara includes relict lakes - the remnants of the seas that occupied this territory millions of years ago. Most of them are more like salt bogs, but there are also freshwater ones.
Flora and fauna of the Sahara Desert
Considering the above factors, it is not surprising that the flora and fauna of the desert is rather poor. All plant species belong to drought-resistant forms and are concentrated in those places where at least sometimes there is water. The animals of the Sahara also live there - mostly snakes and lizards, but there are also representatives of mammals: hyena, fox, mongoose.
The population density here is very low: only two and a half million people live on a huge territory. Some of them are nomadic, but most settled in the oases and along the river banks, engaged in cattle breeding.
The Sahara is divided among themselves by the following ten states: Algeria, Egypt, Libya, Mauritania, Mali, Morocco, Niger, Sudan, Tunisia, Chad.
Nowadays, it continues to "win back" more and more areas from humanity. Scientists' forecasts sound disappointing: if this process does not stop, then in 200-300 years its borders will approach the equator, and in the future the entire African continent will turn into a desert.
