Turpan basin is an intermountain basin on the southern slope of East Tianshan Mountain in Xinjiang, with Turpan as the main one. "Turpan" means "lowland" in Uighur. It is a typical graben basin with the lowest terrain (-15438+0m) and the highest temperature in summer in China. Most of the ground is 500 meters below sea level. Since 1980s, sandstorms have been initially controlled and the ecological environment has been improved by building shelter forests and strengthening irrigation management.
Brief introduction of basin
Turpan basin is surrounded by mountains, located near (90° e, 43° n), and Bogda Mountain in the north and Kalau Mountain in the west are both between 3500 and 4000 m high. Among them, Bogda Peak is 5445 meters above sea level. Jueluotag Mountain in the south is generally below1500m. However, the water level of Aiding Lake at the southern foot of the basin is lower than sea level 154m, which is the lowest depression in China.
If the surrounding ridge line is taken as the boundary, the area is 50 140 square kilometers, of which the area below sea level is 4050 square kilometers, and the Aiding Lake depression is 154 meters above sea level, which is the lowest place in Chinese mainland, surrounded by mountains at the edge of the basin, and the highest Bogda peak is covered with snow all year round.
The elevation of the central part of the basin is about 4,000 square kilometers, the surface of Aiding Lake is-154 meters, and the bottom of the lake is-16 1 meter. There are two east-west low mountains in the middle of the basin, and the northern flaming mountain is below 900 meters; Jueluotag Mountain in the south, about1000 ~1500m; There is an oasis between them.
Flaming Mountain takes this as the alluvial fan at the southern foot of Tianshan Mountain, which is a gravel Gobi with rich groundwater, so Karejing (underground diversion channel) began to take water from it. Rainfall is scarce in the basin, with the average annual rainfall of 16.4 mm in Turpan, 6.9 mm in Toksun and 300-400 mm in the northern mountainous area. There is snow on the top of the mountain, which is the main irrigation water source in the basin. Therefore, the three main oases in the basin (Turpan, Shanshan and Toksun) are located in the north of the middle near the water source.
In order to improve water use efficiency, most irrigation methods are karez. The basin is rich in light and heat resources, with annual sunshine of more than 3000 hours, greater than or equal to 10℃, and annual accumulated temperature of about 5000℃. It is hot in summer, and the average temperature in June-August is above 38℃.
The extreme maximum temperature in the suburbs of Turpan is 49.6℃ (measured at Turpan Airport in July 1975). Rich in light and heat, grapes, melons and long-staple cotton are famous products, and sericulture should also be developed. The basin is rich in oil and gas resources. Lanzhou (State) New (Xinjiang) Railway runs through the river basin, and the South Xinjiang Railway starts from Turpan and has been opened to Korla.
Geological landform
Turpan area is an olive-shaped intermountain basin in the eastern Tianshan Mountains, surrounded by mountains. The basin starts from Alashan Goukou in the west and ends at the west of Qijiaojing Canyon in the east, with a length of 245 kilometers from east to west. In the north is the foothills of Bogda Mountain; South to Kurutag Mountain, about 75 kilometers wide from north to south.
The discovery of ancient fish and dinosaur fossils here proves that it was once a sea. Due to the crustal movement, it gradually turned into land and the basin began to form.
Turpan basin has experienced Jurassic, Cretaceous, Tertiary and Quaternary geological ages, and is an ancient basin gradually depressed. Especially during the Himalayan orogeny 30 million years ago, Bogda Mountain in the northern margin of the basin rose sharply, while Kuruktag Mountain in the northern and southern margins of the basin rose slightly, and the fault between the two mountains collapsed, eventually forming an asymmetric basin with high north, low west and narrow east. There are Flame Mountain and Wula Mountain in Bolto in the middle, which cross the territory and divide the local area into two parts: south and north.
The water level of Lake Aiding at the bottom of the basin is lower than sea level 154m, which is the lowest basin in China and the second lowest in the world after the Dead Sea in Jordan, with a water level of 39 1m below sea level. The aerial view of Turpan basin clearly shows that it is an annular terrain with Aiding Lake as the center and consists of three areas.
The outermost ring is composed of mountains and snow-capped mountains, and Bogda Mountain is in the north, towering into the sky and covered with snow all year round; There is Kurutag Mountain in the south; Kalou is a mountain in the west; There is Kumtag Mountain in the southeast; It can be said that it is surrounded by mountains.
The central part of the basin is a Gobi gravel belt, which has been weathered and eroded by mountains for a long time and carried down by running water. The third zone of the basin is the most dynamic and attractive oasis plain zone.
Most of this area belongs to the sloping plains in mountainous areas, with a large area of fine soil alluvium. Because the Flame Mountain is located in the center of the basin, the groundwater level rises, forming an overflow zone on the north and south edges of the mountain, forming two oases in the south and north, which has become the basis for the people of all ethnic groups in Turpan Basin to thrive from generation to generation. Turpan basin has a mountainous area of 9,850 square kilometers and a plain area of 59,863 square kilometers.
The climate in Turpan basin is extremely dry, with little rain, and the ability of water to carry things naturally is extremely poor, so there is very little sediment in the basin, which is an important reason. In addition, in the fourth neotectonic movement, a flaming mountain from east to west was formed in the middle of the basin. Due to the barrier effect of this low mountain, the weathered materials carried by the running water in Tianshan Mountain can only accumulate in the north of the mountain, while the south of the mountain is protected to avoid accumulation, so it remains below sea level for a long time.
Turpan basin has a special terrain and is surrounded by mountains. The main peak of Bogda Mountain in the north of Turpan Basin is 5445 meters above sea level, and Aiding Lake in the basin is-154 meters above sea level. In such a short horizontal distance, the height difference is 5600 meters, which is naturally a must.
Climatic characteristics
Turpan basin belongs to continental desert climate, which is dry and hot. The annual precipitation is about 16 mm, the evaporation is as high as 3000 mm, the highest temperature in summer has been recorded as 49.6℃, and the average highest temperature in June-August is above 38℃. At noon, the temperature of the sand surface is as high as 82.3℃, so it has been called "Huoshao Island" since ancient times.
The sunshine time is long, about 3200 hours a year, and the frost-free period is about 2 10 days. Because of the low gas pressure in the basin, it attracts airflow, and it is also a famous "wind warehouse" in China. The spring rainstorm from Dabancheng reached 50 meters per second, and the strong wind from Qijiaojing once overturned the vehicle.
Turpan basin belongs to a unique warm temperate arid desert climate. The main features are: dry, high temperature and windy. In the basin, the sunshine time is long throughout the year; Large evaporation; There is little precipitation, but it is local. South of the Flame Mountain, the summer is long and hot, the winter is less cold, and there is less wind and light snow. In spring, the temperature rises rapidly and is unstable, dry and rainy, and the wind is strong. Autumn is crisp, the temperature drops rapidly, and the temperature difference is large. Compared with Shannan, the northern part of Huoyan Mountain has four distinct seasons, with severe cold in winter, extremely hot in ciel phantomhive and more precipitation. Spring and Autumn is half a month longer than Shannan.
The basin is rich in groundwater resources, and its water source is mainly Tianshan snow melt water. In the process of infiltrating into the basin through the underground coarse gravel layer, the meltwater of ice and snow was intercepted by the flaming mountain, gushed out of the ground in the ravine and merged into the river. On both sides of the river, the countryside is lush, beautiful and rich in fruits. The most famous fruit varieties are seedless white grapes and cantaloupe. Located in the grape valley, northeast of Turpan 10 km, for a long time.
The mountain of fire
Famous. The ditch is 7 kilometers long and 2 kilometers wide, and passes through the fire-trapped mountain. The peaks on the east and west sides are opposite, the springs in the ditch flow happily, and the fruit trees are clustered, which is refreshing. Rows of towering poplars are lush, and the grape racks with ditches and slopes are layered. Strings of grapes are as green as jade and dazzling, and are known as "the green pearl of China".
There are three main reasons for the summer heat in Turpan Basin. First, because the climate is particularly dry, there are no clouds in the sky to block the strong sunlight heat, and there is no water evaporation on the ground to consume heat, so we can make full use of sunlight heat to raise the temperature; The second is the basin topography of Turpan, and the heat of the sun is not easy to spread out during the day. Third, the altitude here is low, close to sea level, which is the lowest in the inland arid area of China. The lower the altitude, the higher the temperature, with an average increase of 0.6℃ per 100 meter.
deposit
Turpan is the driest place with the least precipitation in China and one of the arid regions in the world. The annual average precipitation is 16.4mm, and it is unevenly distributed, with large seasonal differences, and there is little continuous precipitation, mostly intermittent. There are more mountains than basins, more in the north and less in the south, decreasing gradually from north to south, and decreasing more and more toward south; Days without precipitation are longer. At the same time, the annual precipitation changes greatly year by year; The most abundant year in northern Shaanxi can reach 76.8 mm (Shanshan 1998), and the youngest is only 12.6 mm (Shanshan 1985). The year with the most precipitation in Shannan can reach 33.4 mm (Turpan 1998), and the year with the least precipitation is only 4.3 mm (Turpan 1976). The annual precipitation is the highest in summer, followed by spring.
Sunlight and evaporation
Turpan has strong solar radiation, long sunshine time and rich light energy. The annual average total radiation is 5938.3 MJ/m2, the longest is 6397.0 MJ/m2, and the youngest is 5648.2 MJ/m2. The maximum value in the middle of the year appears in July, which is 680.3-800.2 MJ/m2, and it is greater in spring than in autumn. The average annual total sunshine hours is 3056.4 hours, the maximum is 3349.6 hours, and the minimum is 2829.7 hours, and the annual sunshine percentage is 69%.
Turpan has a dry climate and strong evaporation capacity, with an average evaporation of 2837.8 mm; The change characteristics of evaporation are: it gradually increases from north to south, and the evaporation is the most vigorous in late spring and early summer, accounting for more than 75% from April to August.
Turpan basin is surrounded by mountains, and the middle is low, so the heat radiated by the surface is not easy to dissipate. It is a famous dry-hot area in China, with an extreme high temperature of 47.8℃ in history. There is little rain in the basin, with sunshine hours of 3,200 hours, annual average precipitation of 16 mm, annual evaporation of more than 2,539.4 mm, and frost-free period of 2 10 days. There are 30-mile wind zone and 100-mile wind zone in the territory, which is known as the "wind warehouse".
Superior light and heat conditions and unique climate make it rich in cash crops such as grapes, cantaloupes and out-of-season vegetables, and it is a veritable "hometown of melons and fruits".
mineral resources
Turpan is rich in mineral resources, with 68 kinds of proven minerals. Coal, petroleum, natural gas, gold, iron, copper, mirabilite, granite, potassium nitrate, sodium nitrate and bentonite have large reserves and high grade, which have great development value and potential. Among them, the predicted coal reserves are 565,654.38+billion tons, and both Shaer Lake and Aiding Lake belong to super-large comprehensive coalfields, with the predicted reserves exceeding 654,380+billion tons; The total oil resources are 654.38+0.58 billion tons, and the total natural gas resources are 365 billion cubic meters. The proven reserves of iron ore are 350 million tons, ranking first in Xinjiang, with reserves of 230 million tons; The proven reserves of potassium nitrate (sodium) are 220 million tons, which is the largest potassium nitrate (sodium) resource in the world. Granite has a large reserve and good color, with a reserve of 8 1.79 million cubic meters. "Shan Shan Hong" has become a famous brand product in China. Montmorillonite is the only large deposit with a certain scale in China. Bentonite reserves rank second in Xinjiang, and it is one of the few sodium bentonite in China.
Wind resources
Wind is also one of the important natural features of Turpan. Strong winds occur in March 3- 10/0 and are strongest in March-June, especially in May, and the wind direction is mainly northwest wind. The terrain of Turpan is very different, the heating area is large and the temperature range is large, which leads to windy weather. Strong winds are mainly affected by local and large weather systems. The former is generally below 10, with short duration and little harm. The latter is fierce and lasts for a long time, and the wind force is above 10, which is very harmful. Turpan is rich in wind energy resources. According to the statistics of Toksun Weather Station, the number of gust days (wind speed ≥ 17.0m/s) above level 6 is 80.3 days per year, the longest 1985 is 127 days per year, and the smallest 1997 is 35 days per year. Especially in the tuyere of Turpan, wind energy resources are more abundant. For example, Baiyang Valley, which is about 100 km long and 10 km wide from Dabancheng to Toksun, has obvious narrow tube effect and strong pressure gradient inside and outside the basin, and is called "wind bank". Therefore, Turpan has inexhaustible, low-cost, pollution-free wind energy resources, and has practical development and application potential.
grape
In Xinjiang, especially in deserts and Gobi, water is the source of life. The flowing water of Karez makes Turpan full of vitality. Here, the solar radiation is strong, the temperature is high and the heat is large.
Grapes in Turpan are of good quality, especially seedless white grapes. The juice is delicious, crystal clear, fresh and delicious, and rich in nutrition. Turpan has a long history of brewing, and the wine brewed here has always been a tribute, not far from Wan Li, and sent to the Central Plains, winning an extraordinary reputation. After the famous Tang Dynasty conquered Gaochang, they brought the brewing technology back to Gaochang. Li Shimin was very happy about it. After a little modification, he brewed eight kinds of famous wines. After tasting it, court officials praised it. Rich and beneficial to plant growth; The temperature difference between day and night is large, the alienation is weak, and the long-staple cotton and fruits produced are excellent. Especially cantaloupe and grape are well-known at home and abroad.