The Sahara desert is the largest desert in the world. Let me show you!
When it comes to Sahara, I have to mention a woman and a book, that is Sanmao and her Story of Sahara. In her works, a distant, mysterious, dreamlike, romantic and affectionate Sahara has been achieved. But when you really set foot in the Sahara, you will find that the Sahara is actually a place that has nothing to do with romance.
the hala desert is the largest desert in the world, but this is not her original face. In the Sahara, where sand and stones are everywhere, there are not only wonderful natural landscapes, but also tenacious life. It is hard for people to imagine that there was a prosperous ancient civilization in such a harsh environment if they didn't see the vivid and varied murals with their own eyes.
The Sahara Desert, located in the northern part of the African continent, is the largest desert in the world except Antarctica, which was formed about 2.5 million years ago. ? Sahara? One is from Arabic, from a local nomadic people? The Tuareg language was introduced, which means? The great desert? .
Location
The Sahara desert is bordered by the Atlantic coast in the west, the Red Sea in the east, the Atlas Mountains in the north and Sudan in the south. It is about 5611 kilometers from east to west, and it runs through 1511 meters from north to south. 2111 kilometers, and across the borders of Morocco, Algeria, Tunisia, Libya, Egypt, Mauritania, Mali, Nigeria, Chad, Sudan and other countries. Sahara desert is the largest desert in the world, covering an area of about 9.6 million square kilometers, accounting for almost one third of the entire African continent. The Sahara region is vast and sparsely populated, with an average of less than 1 people per square kilometer. Arabians are the main people, followed by Bers and others. Residents and agricultural production are mainly distributed in the Nile valley and oasis, and some are mainly nomadic. Since 1951s, abundant minerals such as oil, natural gas, uranium, iron, manganese and phosphate have been discovered in the desert, which has changed the economic outlook of some countries in this area.
The Sahara Desert is divided into three parts: Western Sahara, the central plateau and the eastern desert. The mountainous areas in the central plateau include the Ahagar Plateau in Algeria, the Aier Plateau in Niger and the Tibesti Plateau in Chad, and the highest point of the Sahara desert is located in Kuxi Mountain in the Tibesti Plateau, with an altitude of 3,415 meters. The eastern part is Tenere Desert and Libyan Desert. The Sahara desert divides the African continent into two parts? North Africa and southern Africa. The climate and culture of these two parts are completely different. The southern border is semi-arid savanna, which is called in Arabic? Sahel? Further south is southern Africa with abundant rain and lush plants, which is called in Arabic? Sudan? , which means black Africa.
The Sahara Desert is located near the Tropic of Cancer and has a tropical desert climate. Usually controlled by subtropical high pressure downward flow, the climate is very dry, so it is not easy to form rainfall, even if the rainfall is mostly explosive showers. The average annual rainfall in most areas is less than 111 mm, which is the least in the world. In the central area, even a few drops of rain did not fall for several years. For example, in Kaag, a desert area in Egypt, there was a record of no rain in 2117. Not only that, the evaporation power is very strong, almost more than 21 times or even 111 times that of precipitation, and the relative humidity of the air is also very small. All this has led to a year-round heat wave in the desert area, and the heat is pressing, thus obtaining? World fever? The title of.
if less precipitation and large temperature difference are the characteristics of desert climate, then? How windy and dusty? It is a common weather in the desert. Especially in spring, sandstorms are prevalent and frequent. Whenever a sandstorm comes, the wind roars, flying sand and stones, and suddenly the sky is dark, quicksand is rolling, and sand dunes move with the wind, engulfing large areas of fertile soil and pastures, burying many towns and villages and blocking road traffic. When the sandstorm subsides, there is a thick layer of dust everywhere, and sand piles or dunes are often piled up at the front of the forest. But the weather is particularly sunny, and everything seems clearer than usual. The wind over the sand mountain is particularly bright? The feeling.
In most people's impression, the Sahara should be an undulating area of sand dunes, but in fact there are bare gravel plains, rocky plateaus, steep mountains and salt flats besides sand dunes. The plateau is covered with dry valleys formed by flowing water in the past humid climate. The periphery of the plateau is a large area of rocky desert and gravel desert, and then the sand sea is outside, and the oasis is just an ornament.
The arid landform of the Sahara desert is mainly composed of rocky desert, gravel desert and desert. The storm in the desert blows away the gravel, sand and dust, leaving the rock exposed on the ground, which becomes a rock desert, also known as a stone desert. Stone desert is mostly distributed in the high-lying areas in the central and eastern Sahara. The sand accumulated on the ground was blown away by the wind, leaving stones and stones, which became the gravel desert, which is often called Gobi. Gravel desert is more common between stony desert and desert, and mainly distributed in the rocky areas of Libyan desert, Mount Atras, Kuxi Mountain and other piedmont alluvial fan areas. A large amount of sand deposited in the local area is blown away by the wind, fine dust is blown away, sand is left behind, and the sand carried in the sandstorm is deposited, so that more and more sand is accumulated on the ground and a sand sea is formed? An endless desert. Except for a few high mountains and plateaus, the desert has the widest area. The famous ones are Libyan Desert, Laibuyanai Desert, Obari Desert, Algerian Eastern Desert and Western Desert, Shesh Desert, Zhufu Desert, Arvana Desert and Bilma Desert. The one with a large area is called? Shahai? The sand sea is formed by the complex and regular arrangement of large and small sand dunes, with complex and diverse shapes, including tall fixed sand dunes, low mobile sand dunes and large areas of fixed and semi-fixed sand dunes. The mobile sand dunes are constantly moving along the wind, and there was a record that they moved 9 meters a year.
The Sahara Desert has the largest sand sea in the world. Yellow sand dunes as fine as powder, black sand dunes as black as ink, and white sand dunes as white as silver constitute the most splendid landscape. In the desert, it is said that you can often hear a strange scream, like the roar of a beast and the sound of a whistle. Although there is no rhythm, it sounds very strange, and the wind and sand are walking and screaming. Mirages are also often encountered.
There is a desert called Kosapeka near Morocco, with an area of only 811 square kilometers, but there is a very famous desert in the eastern highlands. Ghost lake? . Because its appearance is unpredictable. For example, in the evening, it seems that there is a big lake with a water depth of 111 feet, but in the morning, it has become a big sand dune of more than 111 feet. Moreover, its appearance is irregular, sometimes during the day, and for ten or eight days in a row, the situation remains the same, and the lake is crystal clear and drinkable. To verify? Ghost lake? The existence of a group of explorers once went to camp near Dangdi. In the middle of the night, the lake suddenly rose from the sand, and the momentum surged rapidly, instantly forming a lake. Fortunately, the explorers escaped in time to survive. But the next day, when they got there again, what they saw was still flat sand. Geogeographers speculate that in? Ghost lake? There may be a place nearby. Ghost lake? A high-lying underground cavity stores groundwater seeping from other places, and there is an underground tunnel like a siphon spring. Ghost lake? Connected to an underground cavity? . When the siphon phenomenon appears, a large amount of water flows out of the underground cavity, and it appears? Ghost lake? And because? Ghost lake? Located on the desert, even if the amount of water is large,
will flow under the sand layer or seep to other places without much effort; Even if the water that has not seeped out for a while, it will be covered by quicksand and become a vast sea of sand in a short time because of the strong wind in the desert and the wind and sand.
The wind in the desert is very strong, and its power is often unexpected. It can blow away the weathered broken gravel and sand grains on the rock surface and enlarge the cracks and fissures in the rock. At the same time, the gravel and sand carried by the wind abrade the rock wall in the upper part of the rock and the cracks and grooves between the rock blocks, so that the rock blocks are gradually ground and deformed. In addition, it can constantly change its carving techniques and strength with the change of wind power and direction, like a skillful craftsman, making all kinds of shapes more wonderful and magnificent. So people call these beautifully shaped scenes? Wind carving? .
There are some grotesque earth mountains in the Sahara desert, most of which are eight or nine meters above the ground. These heaped-up mountains are not only strange in appearance, but also special in composition, because they are formed by the soil grabbed by a termite in the desert and the mucus and excrement secreted by them over a long period of time. These heaped-up mountains have naturally become a beautiful landscape in the desert, but this is also a unique landscape in the Sahara desert, which is rare in other deserts.
The suffocating high temperature, strong sandstorm and bad weather conditions in the vast Sahara desert often make people? Talk about desert color change? . However, its ever-changing desert scenery, continuous sand dune contour lines, various kinds of sand stones with special texture and exquisite characteristic stone carvings strongly attract people to explore and visit.
tenacious life in the desert
On the earth, the places with bad climate, little rain and sandstorm are the most unsuitable places for biological growth.
The Sahara desert that meets the above conditions should be a barren land with thousands of sand dunes and thousands of miles of silence. However, this is not entirely the case, because there are some oases in the vast Sahara desert. Oasis is a place where underground water is exposed or streams are poured, and it is also the center of people's economic activities in desert areas. There are flowing water and lush trees. From a bird's eye view, it looks like a green island in the sand. The periphery of the oasis is palm forest, and the villages and towns are hidden in the depths of the palm forest. The houses there are civil structures, with thick walls and yellow soil on the top. The house is warm in winter and cool in summer, which can prevent both heat and sandstorm. Tall acacia trees, date palms, etc. decorate the yellow sand-filled wilderness with green. There are also dry and hot-resistant plants such as Trifolium repens and cactus that can be seen everywhere, which bring infinite vitality to the vast desert.
The glade is cultivated farmland, and all kinds of crops are planted in the field, among which date palms are the most popular. Date palm is the most common green tree in desert oasis, and it is also a special tree in arid area. The trunk of the date palm tree is tall and straight, the leaves are pinnately compound, the leaves are long and narrow, similar to coconut trees, and the fruit is shaped like dates, so it is named date palm tree. It is drought-resistant, alkali-resistant, heat-resistant and likes humidity. The desert oasis is dry with long sunshine time, little rain in autumn and mild winter, which is very suitable for the growth of date palm trees. Moreover, the hotter the weather, the more fruits the date palm trees produce. Dates are rich in sugar and nutrition, which can be used as food and raw materials for sugar and wine making. Date palms are the staple food of desert residents and the necessary dry food for caravan travel in desert. Not only that, date palms can be made into various sweets, high-grade syrups, biscuits and dishes, as well as vinegar and alcohol, and date stones can also be used as feed. Trunk can be used to build farmhouses and bridges, branches can be used to make chairs, beds and baskets for transporting fruits, vegetables, chickens, ducks, fish and shrimp, leaves can be used to weave mats, bind brooms, make trays, etc., and can also be used as fuel. In a word, date palms are full of treasures.
In the desert, besides date palm trees, there is another plant that is very eye-catching, and that is? A camel thorn? . They either grow in pieces or open in bits and pieces, and the branches with pink flowers sway with the wind, forming a beautiful landscape in the desert. Camel thorn, also known as camel grass, is a natural drought-tolerant plant, with spiny and hard green leaves on its stems, which is named after camel's favorite food. Although the camel thorn is short, its root system is very developed, up to 21 meters long. As long as it absorbs enough water in the rainy season in spring, it can < P > supply a tuft of camel grass for a year, so it can grow in this harsh and dry environment. Camel thorn is not only the main food source of camel, but also known as? Gobi guardian? Strong roots can fix the flow of sand under your feet, which is beneficial to soil and water conservation. Camel spines are drought-resistant, salt-tolerant, and not afraid of wind and sand. Even if they are submerged by quicksand, their roots will grow new buds, and soon they will break out of the sand and continue to reproduce and grow, so they have become a common plant in the Sahara desert.
In addition to drought tolerance and well-developed roots, plants in the Sahara desert can reduce evaporation and consumption of water by themselves. When there is no rain, the part of some plants growing on the sand surface will automatically shrink, greatly reducing the consumption of water. Some plants are born without leaves and rely on the stem part for photosynthesis in order to avoid water evaporation. Some plants shed their leaves automatically in the dry season, so as to keep the moisture in the stems and roots;
Some plants have leaves in the form of rolls, thus reducing the evaporation of water. In short, to survive in the desert, you must have extraordinary skills.
Even though the climate is hot and dry, there are few plants and sand dunes, this does not make the Sahara desert a desperate place for life. There are also many kinds of animals, such as scorpions, snakes, lizards, mice, rabbits, antelopes and camels. There are all kinds of birds living in this land, including ostriches, larks, desert bears, sand chickens and wild geese. They live in small groups, some live in wind-eroded caves on cliffs, and some haunt the bushes in sand dunes? Ostrich is the largest bird in the modern world. It is about 2.5 meters tall and weighs 151 kilograms. Ostriches can adapt to the desert environment very well. They are omnivorous animals and generally live in groups. The ability to endure hunger is also super strong. In the absence of food, sand can also satisfy hunger. Although the wings have degenerated and can't fly, the lower limbs are particularly thick and developed, running like flying in the desert, and the speed can reach 41 kilometers per hour. The ostrich in the Sahara desert is the running champion of the ostrich in the world desert.
among these desert animals, the antelope is the most attractive? People call it? Children of the desert? . Antelopes are gentle and agile, and they run very fast, up to 61 an hour. 71 thousand meters They urinate little, defecate little, and have strong drought tolerance. They feed on psammophytes, their meat is delicious, and their skins can also be made into leather.
lizards are common reptiles in the desert. Lizard is a fierce animal. It never chews when eating. Even food as big as itself is swallowed in one gulp. Lizards live in caves or burrow into sand dunes. They often communicate with sand. In order to prevent sand from sucking into the lung cavity, a special tissue grows in the nostrils. When inhaling, it immediately stands up and gathers into the pores to prevent sand from being inhaled. In addition, there are a pair of well-developed glands in the nostrils, from time to time, mucus flows out and sand accumulated in the nostrils is discharged. The biggest and fiercest lizard is the monitor lizard. It is 1 meters long.