Taklimakan Desert

Taklimakan Desert

This entry is compiled and applied by "popular science China" Science Encyclopedia

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Taklimakan Desert (Uyghur: تكلىماكنقۇمۇى) is located in the center of Tarim Basin in southern Xinjiang. It is the largest desert in China, the tenth largest desert in the world, and the second largest mobile desert in the world. The desert is about 1000 kilometers long from east to west and 400 kilometers wide from north to south, covering an area of 330000 square kilometers. The average annual precipitation is less than 100 mm, and the lowest is only 45 mm, while the average evaporation is 2500-3400 mm. Here, pyramidal dunes stand 300 meters above the plain. Strong winds can lift sand walls up to three times their height. The sand dunes in the desert are continuous and often move due to the influence of wind. There are also a small number of plants in the desert, whose roots are extremely developed, tens or even hundreds of times more than the aboveground parts, in order to absorb underground water. The animals there have the phenomenon of dormancy.

The origin of the name

Taklimakan desert is a cursed and submerged city in Uygur legend. The word "Taklimakan" is divided into two parts, "Taklimakan" and "maklimakan", in which "Taklimakan" means "underground", "below"; "maklimakan" means "field", "home", "place to live"; therefore, "Taklimakan" means "underground city" or "underground City".

geographical environment

position

The whole desert is about 1000 kilometers long from east to west and 400 kilometers wide from south to north, covering a total area of 337600 square kilometers. It is distributed in four regions of Xinjiang: Bayinguoleng, Aksu, Kashgar and Hotan. It is the largest desert in China, so it is called "Taklimakan Desert". It is also the second largest mobile desert in the world, next only to the lubkhari desert (650000 square kilometers) in the Arabian Peninsula The area of quicksand is the largest in the world.

Taklimakan Desert

landforms

The altitude of desert is 1200-1500 meters in the West and south, and 800-1000 meters in the East and North. The dunes are up to 200 meters high. Data also show that Taklimakan desert is the second largest mobile desert in the world. Taklimakan hinterland is rated as one of the five most beautiful deserts in China.

Located in the center of Eurasia and surrounded by mountains, the Taklimakan desert is full of fantasy and mystery.

The area of mobile sand dunes in Taklimakan desert is very large. The height of sand dunes is generally 100-200m, and the highest is about 300m. The types of sand dunes are complex and diverse. The complex sand hills and ridges are like giant dragons resting on the earth. The tower shaped sand dunes are in various honeycomb, feather and fish scale shapes, which are unpredictable.

There are two red and white high dunes in the desert, named "Shengmu mountain". They are respectively composed of red sandstone and white gypsum, and the sedimentary rocks are formed after exposed to the ground. The wind erosion mushroom on the "holy tomb mountain" is spectacular, about 5 meters high, and can accommodate more than 10 people under the huge cover.

The Taklimakan desert is flanked by majestic mountains: Tianshan Mountain in the north, Kunlun Mountain in the south, and Pamir Plateau in the West. In the South and West, between the desert and the mountains, there is a slope desert lowland composed of pebble clastic sediments.

Several small mountains and mountain chains are formed by sandstone and clay of Paleogene and Neogene (66.4 million to 1.6 million years ago) and uplift in the west of the desert. The arc-shaped mazala mountains, between Hotan and Yeerqiang River Valley, arc to the southwest.

It is 145 km long and 3-5 km wide, with the highest altitude of 1635 meters. It is only 300-350 meters higher than the surface of Shayuan. Nearby is another isolated mountain, surrounded by mobile sand dunes on all sides; the tokhtakaz mountains are 1560m above sea level, 183-244m higher than the plain.

The surface of Taklimakan desert is formed by loose alluvium hundreds of meters thick. This alluvium is affected by the wind, and the sand cover moved by the wind is 300 meters thick. The topographic features of wind formation are various, and dunes of various shapes and sizes can be seen.

The larger dune chain ranges from 30 to 150 meters high, 240 to 503 meters wide, and the distance between chains is 0.8 to 5 kilometers. The highest topographic form of wind is pyramid shaped sand dunes, 195-300m high. In the East and middle of the desert, the sand dunes in the middle depression and the net formed by huge and complex sand dune chains are the main ones.

 

It is also common in the west of the desert (east of the Hotan River Valley), where the transverse and longitudinal (wind direction) topographical forms coexist. Such a wind forms a variety of topographic features, which is a result of the complex situation of basin wind.

climate

Taklimakan desert is a warm temperate arid desert. The highest temperature in hot summer is 67.2 ℃, and the temperature difference between day and night is more than 40 ℃. The average annual precipitation is less than 100 mm, and the lowest is only 45 mm. The average evaporation is 2500-3400 mm.

 

The climate of Taklimakan desert is warm and moderate, which is obviously continental. The annual maximum temperature is 39 ℃. Annual precipitation is very low, ranging from 38 mm in the west to 10 mm in the East. The temperature is high in summer, and it can be as high as 38 ℃ in the eastern edge of the desert.

 

The average temperature in the eastern region in July is 25 ℃. Cold winter: the average temperature in January is - 9 ~ - 10 ℃, and the lowest temperature in winter is generally below - 20 ℃. One third of the year is sandstorm day. Due to the cross influence of the northwest and North-South prevailing wind directions, the wind sand activities are very frequent and intense, and the mobile dunes account for more than 80%.

 

It is estimated that the low sand dunes can move about 20 meters every year. In the past 1000 years, the whole desert has extended about 100 kilometers to the south.

Northerly and northwesterly winds prevail in summer in Western China. After the two kinds of air flow meet near the desert center at the northernmost end of the Keriya River, a complex circulation system is formed, which is clearly reflected in the shape of sand dunes.

In spring, when the surface sediment is warm, the updraft develops, and the northeast wind is especially strong. During this period, strong hurricane dust storms often occur, making the atmosphere full of dust, up to 3962 meters above sea level. Wind from other directions also brings dust into the air, covering the Taklimakan Desert almost all year round.

In the daytime, Taklimakan is red and the silver sand is dazzling. The temperature of the sand surface is sometimes as high as 70-80 degrees. The vigorous evaporation makes the surface scenery erratic. Desert travelers often see hazy "mirages" in the distance.

rivers

Around the desert, there are Yeerqiang River, Tarim River, Hotan River and Che'erchen River running through the two banks. As Tarim Basin is an internal water system basin, all the runoff from the surrounding mountains is gathered in the basin itself to supply water for the river and groundwater.

Most of the groundwater under the desert has a continuous channel, flowing from the west to Lop Nur in the East. Due to the small rainfall and high evaporation rate, rainfall is negligible for moistening the desert and supplying groundwater.

The rivers of Kunlun Mountains and rivers infiltrated into the desert for 100-200 km, and gradually dried up in the desert. Only the Hotan River passes through the hinterland of the desert, and can flow into the Tarim River occasionally in summer.

natural resources

Botany

The Taklimakan desert is extremely sparsely vegetated; almost the whole area is devoid of vegetation. In the depression between the sand dunes, the groundwater is not more than 3-5 meters away from the surface, and there are sparse Tamarix, nitre shrubs and reeds. However, the thick quicksand layer hinders the spread of this vegetation.

Vegetation is abundant at the edge of desert, where sand dunes meet river valleys and deltas, and where groundwater is relatively close to the surface. There, in addition to the above plants, there are some valley specific varieties: Populus euphratica, Elaeagnus Elaeagnus, Alhagi, Tribulus terrestris and Salsola. Dunes on hills often form around shrubs.

Around the desert, dense Populus euphratica forest and Tamarix shrub grow and develop, forming "sand sea green island". Especially on both sides of Hetian River, which runs through the desert, there are many kinds of sandy weeds, such as perennial reed, Populus euphratica, etc., which form the "green corridor" in the desert. The water in the corridor is gurgling and the oasis is connected.

Rabbits and birds live in the forest belt