The problem of desertification
Desertification is now a problem to be reckoned with, with more than 20 per cent of the earth's fertile land degraded.
Desertification is still eroding other lands at a faster rate, so fast that people sometimes have no time to respond to it.
According to United Nations statistics, 12 million hectares of fertile land disappear every year as a result of desertification.
That is, 2,000 football fields of soil turn to sand every hour.
As the global population grows further, humanity needs more food production, and the total amount of food needed in the next 40 years must exceed the amount of food produced by humans in the past 500 years combined.
FAO at the United Nations Convention to Combat Desertification
As the most successful country in the world for greening, China's achievements are obvious to all in the world.
For decades, the heroes of the desert have turned the desert into an oasis step by step through the efforts of generations.
Once one of the worst sands on the mainland, the Mu Usu Sandy Land is now surrounded by green water and wooded.
For the northwest region, drought and lack of water, the desert Gobi makes life here a difficult task.
But it turns out that deserts can be changed under the influence of humans, as long as they are through a reasonable scientific method and persistent labor.
Although the mainland has solved the problem of desertification in many areas by returning farmland to forests and grasslands, sustainable development has become an important local policy.
But in Xinjiang, there is still one of the most difficult bones to gnaw, the Taklamakan Desert.
It is the second most mobile desert in the world, with flowing dunes covering an area of about 277,000 square kilometers, accounting for 82% of the total desert area.
This means that it will not be too easy to govern the desert.
Geographical map of the Taklamakan Desert
In addition, the average precipitation of the Taklamakan Desert is 100 mm, the minimum can reach 4 to 5 mm, and the average annual evaporation of 2500 mm makes it difficult to retain water.
The sand walls blown by the fierce wind can reach hundreds of meters, and the sand can easily bury any plant with poor sand protection ability.
From the Tianshan Mountains, Kunlun Mountains, Arjin Mountains and the Pamir Plateau in Xinjiang -
The east-west corridor is more than 1,100 kilometers, the north-south width is 550 kilometers, and the area reaches 337,600 square kilometers, accounting for half of the entire Chinese desert area.
Aerial view of the Taklamakan Desert
Its formation also has more complex factors, which are largely related to the Qinghai-Tibet Plateau.
According to an investigation by the Chinese Academy of Sciences, the Taklamakan Desert has existed for at least 5.3 million years.
And in the process of formation, the formation of the southwest direction of the desert also contains a large number of loess moved by wind movement, which is piled up here to form the formation of the Cenozoic.
It is precisely such a huge desert that makes it difficult for Xinjiang to develop its economy and also brings great difficulties to the surrounding areas.
Of course, some people say that if the Taklamakan Desert can be treated, Xinjiang will become better, and perhaps China's entire environment will also improve.
A view of a large desert
In other words, can the mainland wipe out the Taklamakan Desert?
The governance of large deserts is possible
To solve this problem, we can analyze it from the location of the entire desert, as well as the geographical environment, including desert movement.
As a mobile desert, the largest area of the Taklamakan Mobile Desert is in the eastern Tarim Basin.
It is close to the Hexi Corridor region of Gansu, which is the key area to control the sandstorms in Xinjiang.
The problem, however, is that this area is located in the heart of the desert, with almost no water system and little vegetation, making it difficult to fix water.
Its northern edge is downstream of the Tarim, which is also a water-scarce place, so it will be difficult to manage.
Desert distribution in China
Considering the geographical location of the desert and the characteristics of the basin, the lack of precipitation and the large annual evaporation are the main disturbance factors.
Therefore, one of the main ways to control the Taklamakan Desert is to divert water to the surrounding areas and reduce the harm of the mobile desert and sandstorms by building canals to divert water.
As the saying goes, sand control is first water, if it is not soil erosion, then how can desertification occur?
One of the current discussion options is to divert water from the Tibetan Plateau to the west, or from the Bohai Sea region to solve the drought problem in the northwest.
Possible water transfer schemes in Tibet
Technically, it's not too much of a problem, and the problem with the solution is that it's going to be a hugely expensive project.
Far water does not quench the thirst of the near, and it is not feasible in the short term.
Then we turn to Xinjiang itself, there are high mountains on the northwest border of Xinjiang, and high mountains mean that there is abundant glacier water and precipitation.
Although Xinjiang is deep inland, the annual precipitation in this area is more than 400 mm, so it can be considered to use water diversion for treatment.
In addition, the unreasonable development and use of the Tarim River is also a major problem.
Tarim Hanoi's wetland system
Extensive water use causes the downstream of the river to stop flowing, which in turn leads to the deterioration of the surrounding desert ecology.
If the water supply in the region can be ensured to be reasonable, and water is diverted from the north and south banks to the hinterland of the Taklamakan Desert, the desert flow can be reduced.
Local water management and water diversion and canal construction can minimize the impact of mobile deserts, thereby improving the ecological environment of mobile desert areas.
In the process of sand control, we can use methods such as grass squares to solidify water and soil, and develop aeolian shelterbelts to protect the green areas around the desert.
Sandy land after returning farmland to forest
This is only one aspect of this, on the other hand, there is population activity and the rational implementation of the surrounding policy of returning farmland to forests, and the scientific method of controlling the desert.
From the perspective of technology and reserve strength, the mainland has the ability to improve the environment of the Taklamakan Desert, but this will undoubtedly consume a lot of national strength, and it may not be possible to see results in the short term.
Another point is that such a huge desert, if it disappears into a grassland, is it good or bad?
At this time, someone must say that the desert has become grassland, is this not good? Today, we advocate reducing carbon emissions, protecting the earth, saving energy and reducing emissions.
If the Taklamakan Desert is completely treated, China will certainly become the most powerful country in sand control.
The role of deserts in natural systems
Don't say it so deadly, in fact, the desert itself is also part of the earth's environmental system.
Not to mention that the Taklamakan Desert is so vast that its impact on the environment cannot be underestimated.
In a joint survey, the Desert Meteorological Research Institute of the China Meteorological Administration and the Taklamakan Desert Research Institute in Xinjiang found:
The role of the Taklamakan Desert is even greater than we think.
Desert researchers have found for the first time in the study that deserts can isolate carbon dioxide through non-photosynthetic processes, and that its contribution to the total carbon dioxide exchange activity of shifting sands is surprisingly strong.
The scientists collected data from multiple analytical instruments and displayed the results of group tests.
Mobile sand releases carbon dioxide during the day and peaks at noon, and at night, the mobile desert absorbs carbon dioxide from the atmosphere and carbon fixes it.
Changes in the CO2 flux of the instrument during synchronous observation
Through comparative analysis of the measurement of mobile sandy lands, this effect was also verified in experiments in the Taklamakan Desert, the Mu Usu Desert and the Gurbantunggut Desert.
Heat fluctuations in quicksand cause soil air containing carbon dioxide to expand and contract, while salinity in sand controls the release and absorption of carbon dioxide in the soil.
This explains why sand releases carbon dioxide during the day and absorbs carbon dioxide at night.
Further revised proofreading analysis by the scientists showed fluctuations in carbon dioxide flux in the shifting sands of the Taklamakan Desert hinterland.
After correction, the desert has a relatively strong absorption effect in the dynamic balance of release and absorption throughout the year.
Corrected data for CO2 fluxes
If the carbon sequestration rate of the quicksand in the hinterland of the river is taken as a reference, and 70% of the quicksand area of the river is expanded, then the carbon sequestration of the river quicksand is 1488500 tons per year.
This suggests that even deserts can play a positive role in mitigating climate warming.
In addition, scientists hypothesized that if the average carbon sequestration rate of quicksand in the hinterland of the Taklamakan Desert is used as a benchmark, the global mobile desert system can carbon fix about 200 million tons of carbon dioxide per year.
However, as global climate change warms, the expansion effect of the temperature difference in the sand makes carbon dioxide release more, and the ability to be fixed is gradually decreasing.
As a result, the carbon fixation capacity of the Taklamakan Desert is weakening at a rate of 0.4% per year.
Therefore, desert governance is not a hammer deal, it requires us to look at it comprehensively.
While managing the desert, it is possible to keep it in good shape, or even maintain the status quo. As part of a natural ecosystem, the role of deserts is far more important than we think.