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Why there are “lakes” in the Taklamakan Desert

  In the arid and barren vast sea of ​​sand, there are puddles of blue and shining lake water. The yellow sand and the clear water complement each other, shining brightly under the sunlight, and the scene is spectacular. Not long ago, the video of “a lake appeared in the Taklimakan Desert in Xinjiang” rushed into the hot search and attracted social attention.
  Why do “lakes” appear in the desert? Does it mean that “deserts turning into oases” will become a reality? What impacts do desert lakes have on the production and life of local people? To this end, the reporter interviewed authoritative experts to respond to social concerns.
Where did the “lake” come from?

  Located in the center of the Tarim Basin in southern Xinjiang, the Taklimakan Desert is the largest desert in my country, with a length of about 1,000 kilometers from east to west and about 400 kilometers from north to south.
  Here has an extremely arid desert climate. The high temperature in the hot summer season can reach about 67 degrees Celsius. The average annual precipitation is around 100 mm, and the extreme value is 4 mm to 5 mm.
  In such a “sea of ​​death”, why do “lakes” appear?
  ”These ‘lakes’ mentioned in the news are not lakes in the traditional sense. These ‘lakes’ are ‘reservoirs’ or ‘reservoirs’ formed by floodplain water overflowing from the Tarim River after the water volume of the Tarim River increased. Duan Weili, a researcher at the Xinjiang Institute of Ecology and Geography of the Chinese Academy of Sciences, pointed out straight to the point that this “lake” is not the other “lake”.
  He analyzed that these temporary water surfaces are not the same as the long-term lakes in the desert itself.
  ”There are lakes in the Taklamakan Desert, that’s true.” Duan Weili changed the subject, “Like Lop Nur, known as the ‘Earth of the Earth’, Taitma Lake, which once dried up and has now recovered, and Lop Lake, now Compared with the 1970s and 1980s, the water area has increased.”

  ”These lakes belong to tail lakes, and they were formed because of a continuous and stable water supply.” Duan Weili said, from the video, these new “lakes” in the desert obviously do not belong to this situation. They are considered as temporary water storage points. It is more appropriate to call them ponds. The accumulated water formed in the lowlands by the overflow of the Tarim River will disappear due to infiltration and evaporation after a while.
  So, what causes these temporary “lakes” to appear?
  Duan Weili, who has been focusing on water resources research in Xinjiang for a long time and is currently undertaking the third water resources investigation in Xinjiang, said that this has the most direct relationship with the water volume of the Tarim River. This year is the year with the largest amount of water in the Tarim River in the past 10 years. Since May, the high temperature has caused a sharp increase in the melting water of glaciers and snow in the high mountain area, combined with the impact of heavy rain in the upper mountainous areas of the basin, causing the Tarim River to exceed the warning water level. This year, the water system of the Tarim River Basin has expanded significantly, and the river water has soared and drained into the desert lowlands, forming so-called “lakes.”
  Yao Junqiang, deputy director of the Urumqi Institute of Desert Meteorology of the China Meteorological Administration, agreed.
  Yao Junqiang introduced that this summer, the entire northern hemisphere, including Xinjiang, was shrouded in high temperatures, breaking the high temperature records in recent years, including the Qinghai-Tibet Plateau and the Kunlun Mountains and Tianshan Mountains on the north and south sides of the Tarim Basin. At the same time, precipitation in July and August caused the source streams of the Tarim River, the Aksu River, the Yarkand River, the Kaidu River, and the Hotan River to run above the warning water level, and flood peaks appeared many times.

  ”This year’s flood is not only large in volume, but also lasts for a long time.” Yao Junqiang said that according to the information he has consulted, from late May to late September this year, the runoff of the upper reaches of the Tarim River was 150% higher than that of the same period in previous years. Floods above the warning level occurred in 25 rivers, which lasted for more than 80 days, setting a record in recent decades.
  ”During the flood, the water level of the Tarim River rose, and the river overflowed and flowed to the lower-lying areas in the Taklamakan Desert, forming so-called ‘lakes’; and more flood resources were diverted, diverted, and ecologically diverted. It has been transported to ecological protection areas such as wetlands and Populus euphratica forest along the coast, realizing the resource utilization of flood waters.” Yao Junqiang said.
Can “Desert Oasis” Reappear

  With the increase of glacial meltwater, many people have linked this with the trend of “warming and humidification” in the Northwest. Some point out that the appearance of these “lakes” may be a precursor to the recovery of the “Loulan Oasis”.
  ”There is no scientific basis for such a view. The appearance of a temporary ‘lake’ is an extreme meteorological and hydrological event, and it does not mean that a warm and humid climate has appeared in the arid area of ​​​​the Northwest. It is also difficult for netizens to turn the desert into an oasis.” In response Yao Junqiang said when netizens proposed to use the new “lake” to plant trees and turn the desert into an oasis.
  Yao Junqiang said that in the short term, the Tarim River flood process has a positive impact on agriculture and forestry in the desert areas on both sides of the river. However, the area of ​​the remaining water body is relatively small, and the existence time is relatively short, so it cannot have a substantial impact on the regional climate.
  Duan Weili also expressed the same view. “The oasis in the desert must have a stable water source to maintain a certain area. The lake formed by this temporary overflow will soon disappear under the action of evaporation and seepage, and it is difficult to become the oasis we imagined. He said that in order to plant trees in the desert, you need suitable soil, continuous artificial tending and continuous water supply. It is not realistic to rely on these temporary lakes for support.
  In recent years, precipitation in Northwest China has increased significantly. Does the appearance of lakes in the desert further confirm the trend of “warming and humidification” in the western region?
  Duan Weili analyzed that the wet and dry conditions of an area generally depend on the combined effect of precipitation and evaporation, and the two most direct factors are precipitation and temperature. In the past 60 years, the precipitation in Northwest China has increased at a rate of about 9.3 millimeters per decade. Although the increase was large, the increase in total precipitation was very limited. At the same time, in the past 60 years, the average annual temperature in the arid region of Northwest China has been rising at a rate of about 0.32°C per decade. Under the conditions of rapid temperature rise and increasing precipitation, the actual evaporation in this arid region is increasing at a rate of about 11.9 millimeters per decade, while many areas originally had an average annual potential evaporation of more than 2000 millimeters. Therefore, the increase in water can completely offset or even be ignored for the evaporation effect. In other words, the effect of “wet” is not obvious at present.

  Yao Junqiang said that in recent years, the arid regions of Xinjiang, including the Taklimakan Desert, have clearly felt that the total amount of precipitation has increased, but the frequency of precipitation has decreased. That is to say, the number of torrential rains is increasing, the number of moderate and light rains is decreasing, and the probability of floods and droughts is increasing. This reminds us that we should take more active measures to intervene, “such as building a reservoir in the upper reaches of the Tarim River and continuing to carry out ecological water transfer to the Populus euphratica forest will have a positive impact on the climate.”

  Facing the reality of increasing water flow in the Tarim River, how to make good use of these “living water” while avoiding disadvantages? At the same time, how should the areas along the line take precautions to eliminate the possible adverse effects of heavy rain and floods?
How to use water resources scientifically

  Facing the reality of increasing water flow in the Tarim River, how to make good use of these “living water” while avoiding disadvantages? At the same time, how should the areas along the line take precautions to eliminate the possible adverse effects of heavy rain and floods?
  ”Water resources are the most important natural factor for economic and social development and ecological environment protection in southern Xinjiang. In recent decades, the amount of water coming from the mountainous areas of the Tarim River Basin has fluctuated and increased. To use water resources scientifically, it is necessary to focus on scientific water disaster prevention and control, Water resources planning and management, let water resources for my own use.” Duan Weili analyzed.
  In fact, in Yuli County, Bayingolin Mongolian Autonomous Prefecture, where the beautiful scenery of desert “lakes” appears, with the increasing abundance of water resources and the optimization of the ecological environment, the crab breeding industry has flourished.
  This summer, the plump and plump “June Yellow” harvested in Lobu Lake this summer and became the “new favorite” on the tables of local residents. According to Chu Ningning, the person in charge of the farm, thanks to the water quality of Lobu Lake, which contains a small amount of saline and alkali, and the “human-free-breeding” farming model, the survival rate of crab seedlings has reached 98%. This year, the farm invested a total of 50,000 yuan in Yangtze River crab seedlings, and the crab output is expected to reach 20 tons.

  On both sides of the Tarim River, in order to make good use of water resources, the implementation of ecological water replenishment in key Populus euphratica forest reserves has become the focus of local ink. Xinjiang Tarim River Basin Administration, in accordance with the principles of precise allocation, targeted water delivery, and system assessment, and the Xinjiang Institute of Habitat and Geology of the Chinese Academy of Sciences, determined the ecological protection goals of three-year irrigation and full coverage of Populus euphratica forest, and designated 24 affected areas. In the water area, 37 water delivery channels were dredged to transport ecological water to areas that are far away from the river, were not covered in the past, and showed signs of ecological degradation, so that the original Populus euphratica forest in Xinjiang can “drink enough” ecological water.
  As of mid-October, Xinjiang has completed a total of 2.639 billion cubic meters of flood diversion and replenishment for Populus euphratica forests, 1.283 billion cubic meters more than the same period last year. The results of the staged analysis of the Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences show that the total area of ​​Populus euphratica forest with ecological replenishment and flood irrigation is about 5.82 million mu, of which the area of ​​Populus euphratica forest is about 2.36 million mu with flood diversion and flood irrigation. , the ecological environment continues to improve.
  ”The key to taking precautions is to use the system concept as a guide to further improve the scientific overall allocation of water resources, strengthen the construction of water conservancy projects, and realize the two-pronged approach of prevention and utilization through the utilization of flood resources. While improving the ecological environment, effective Help economic and social development.” Duan Weili said.

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