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Summary:We need to re-take stock of our assets in order to plan the future development of Xinjiang.

In the 1950s and 1980s, my country conducted two large-scale scientific surveys in Xinjiang, and initially took stock of Xinjiang's water, soil, biological resources, mineral resources, etc. At the end of 2021, 29 professional scientific expedition teams and more than 3,500 scientific and technological workers from across the country gathered again and set out for the third comprehensive scientific survey of Xinjiang.

In the recent CCTV program "China Economic Lecture Hall", Chen Xi, deputy leader of the third Xinjiang scientific expedition team and researcher at the Xinjiang Institute of Ecology and Geography of the Chinese Academy of Sciences, introduced the latest results of the Xinjiang scientific expedition. The following is the main content of the speech.

Chen Xi, researcher at Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences

"Water resources investigation is the top priority of scientific research"

Xinjiang is the geographical center of the Asian continent and the most continental region in the world. With a total area of ​​1.66 million square kilometers, accounting for about 1/6 of my country's total land area, Xinjiang not only has unparalleled beauty, but is also a treasure trove of natural resources.

Interestingly, the Chinese character "疆" in Xinjiang directly reflects the topographic structure of "three mountains and two basins". The three horizontal lines on the right side of the character "疆" represent three mountains: the top horizontal line is the Altai Mountains in the north, the middle horizontal line is the Tianshan Mountains, and the bottom horizontal line is the Kunlun Mountains in the south. The two "田" characters in the middle, the top one is the Junggar Basin, and the bottom one is the Tarim Basin.

Xinjiang is the core area of ​​the Silk Road Economic Belt. It has established trade relations with 181 countries and regions in the world. At the same time, oil and gas, petrochemicals, coal, coal-fired power, coal chemical bases, wind power, photovoltaic bases, etc. are all being built in Xinjiang. The rapid development of social economy has brought pressure to Xinjiang's future resource utilization and ecological environment protection. Therefore, we need to re-inventory our "family assets" and plan for Xinjiang's future development.

The top priority of the third Xinjiang comprehensive scientific expedition is to explore the origins and development of Xinjiang's water resources, because water resources are the lifeline of Xinjiang. With water, there are oases, and without water, it becomes a desert. This is its unique geographical and hydrological characteristics.

Where does Xinjiang's water come from? Mountains are where Xinjiang's precipitation is concentrated, with precipitation reaching 600 mm to 1,000 mm per year. Therefore, mountains are a key area for the formation of Xinjiang's water resources. At the same time, glaciers and snow account for 50% to 60% of Xinjiang's water resources. Therefore, glaciers and snow are an important part of Xinjiang's water resources.

Taking into account the characteristics of Xinjiang's water resources, our scientific expedition team has made glaciers and snow a core task of investigation in this survey.

Let's first look at the Irtysh River in the north. The Irtysh River is the only river in China that flows into the Arctic Ocean. It originates from the southern slope of the Altai Mountains, flows through Kazakhstan and Russia, and finally flows into the Arctic Ocean. The river is 4,248 kilometers long, 546 kilometers of which are in China, and the annual runoff is about 11 billion cubic meters. The Irtysh River in China has a large amount of water, and both sides of the river are lushly planted.

The Wucai Beach Scenic Area on the north bank of the Irtysh River is extremely beautiful. (Photo by Xinhua News Agency)

One of the major discoveries of our expedition is that the global temperature rise has reduced the amount of water in the Irtysh River. The Irtysh River is mainly replenished by snowmelt, icemelt and precipitation. According to our observations and the use of remote sensing, drones and other technical means to verify the amount of water in the Irtysh River, we found that the amount of water in the Irtysh River has decreased. Due to the rise in temperature, the glaciers and snow at the source of the Irtysh River have changed greatly. Compared with 30 years ago, the glacier area has decreased by 15% to 20%, and the snow depth has decreased by about 3 cm every 10 years. According to climate and hydrological forecasts, the glaciers at the source of the Irtysh River will continue to shrink in the next 30 years.

We also focused on the Tarim River. The Tarim River is the mother river of the Tarim Basin. It originates from the Tianshan Mountains and the Karakoram Mountains. The oases south of the Tianshan Mountains are basically irrigated by the Tarim River. We also focused on glaciers and snow. Through remote sensing and field surveys, we compared the glacier catalogs of the first and second scientific expeditions to the Tarim River Basin and found that the glacier area is also decreasing.

After this investigation, we basically clarified the data of Xinjiang's water resources in the past 30 years, including rivers, groundwater, glacier meltwater and snowmelt water, updated Xinjiang's glacier catalog, and conducted a census of Xinjiang's water resources.

"Xinjiang wild apple is the "ancestor" of other apples"

Xinjiang has mountains, grasslands, forests, deserts, wetlands and Gobi, which complement each other and give birth to unique species resources and biodiversity on this land. Since the establishment of the first nature reserve in 1980, Xinjiang currently has 28 national and autonomous region-level nature reserves, accounting for 10.8% of Xinjiang's total area.

The Ili River Basin is the concentrated area of ​​the wild fruit forests in the Tianshan Mountains. We conducted a detailed investigation and survey of the wild fruit forests in the Ili River Tianshan area, collected a large number of flower, fruit, leaf, branch and soil specimens as well as various insects for analysis, and found that the Ili River, especially the area within Xinyuan County, is the birthplace of apples, walnuts, apricots, pears and other fruits in the world.

Why is this the birthplace of apples, walnuts, apricots, pears and other fruits in the world? This scientific survey confirmed that there are 469 species of wild fruit forests in this area. For example, Xinjiang's wild apples, also known as Sevastopol apples, have 84 types in this area, that is, there are 84 types of one type of apple. There are 46 types of wild apricots, 21 types of cherries, and 14 types of walnuts, indicating that the species diversity in this area is very rich.

We sequenced the genomes of all 117 cultivated apple species in the world and compared them with the wild apples here, and found that the wild apples in Xinjiang are the "ancestors" of all apples in the world.

So how did they spread from Yili? They spread outward through fragmented pollen transmission. Some were spread along the westerly circulation, some were carried by insects and birds. Some, like the Japanese Fuji apple, were hybridized from fruit tree seeds collected directly from Yili in Japan.

The preservation of wild apple genes is very important because if you want to improve the quality of apples, you need to go to its ancestral home, the Yili wild fruit forest, to collect the most original genes for trait improvement. It can also be seen that the wildlife resources in the Yili River Basin in Xinjiang are extremely valuable.

However, our survey found that the wild fruit forests in the Yili River Basin have been declining over the past 20 years. Why is it declining? Through investigation and research, we found that the biggest threat to wild fruit forests is an insect called the apple borer. This insect is an invasive pest. Before this pest existed, the local wild fruit forests grew very lush. This insect will drill into the trunk of the tree and cannot be seen on the surface. Its adults and larvae are inside the trunk, so pesticides alone are not very effective, so it is very harmful to fruit trees.

In response to the problem of apple borer, we are now using biological pest control technology to kill the apple borer's natural enemies. We have created a large-scale artificial breeding technology for natural enemies. On the basis of killing pests, we have also adopted rejuvenation and renewal technology to restore wild fruit trees. At present, 80% of Xinjiang's wild fruit trees have been restored, and lush fruit trees have begun to grow again.

During the survey of aquatic life in the Irtysh River, we also accidentally discovered a new species of gammarus. The gammarus in the Irtysh River is significantly different from those in other areas. We called this new species the Hebuksai gammarus.

On this basis, we further studied the gammarus in the Altai Mountains and the Tianshan Mountains using genomic methods, and found that gammarus showed a diverse distribution in Xinjiang, with a total of 9 major types. After comparing the genomes of gammarus with those in other regions of the world, we found that all invertebrate cold-water animals in the world, represented by gammarus, originated from the Tianshan Mountains. Later, with large-scale climate and geological changes, gammarus gradually expanded to Central Asia through rivers and lakes, and then came to Europe.

Populus euphratica forest in the Tarim River Basin of Xinjiang. (Photo by Xinhua News Agency)

In addition, the Tarim River in Xinjiang is the main distribution area of ​​Populus euphratica in the world, and 90% of the world's Populus euphratica is concentrated in this area. Therefore, Populus euphratica is a very precious species for Xinjiang and China.

Populus euphratica forest is a typical riparian forest distributed on both sides of arid areas. Its survival mainly depends on the following water sources: first, flood water and second, groundwater on both sides. Flood water can also spread Populus euphratica seeds and provide water to young Populus euphratica, allowing them to grow quickly and renew the Populus euphratica forest. Groundwater provides the main water source for the survival of Populus euphratica.

In recent years, my country has invested nearly 10 billion yuan in the Tarim River ecological governance project. The project has two purposes: the first is to prevent the two deserts in the lower reaches of the Tarim River from merging, and the second is to protect this poplar forest.

This time, we found through precise measurements by drones that although the Populus euphratica forests on both sides of the Taiwan Strait are growing better, their overall structure is not reasonable. Why do we say that?

The survival limit of Populus euphratica is when the groundwater level reaches 9 meters, 6 meters is its survival warning line, and above 4 meters is the environment suitable for its survival. Although ecological projects have continuously raised the groundwater level on both sides of the Tarim River, which has met the basic requirements for the growth of Populus euphratica forests, the results of this survey also show that the growth of Populus euphratica forests is getting better, but the structure of the Populus euphratica forests is relatively old, that is, there are more old and middle-aged Populus euphratica, and few new young Populus euphratica.

This is because a relatively complete canal system has been built on both sides of the Tarim River, and the flood overflow phenomenon has been reduced, so there are fewer young poplars. In the future, we plan to set up ecological gates in some key areas to release some flood water to both sides, so that poplar seeds can take root there and grow as quickly as possible, constantly renewing the poplar population.

"The Sea of ​​Death has its uses"

Xinjiang not only has rich biological resources, but also has a life forbidden zone that makes all living things feel despair, that is, the desert.

Xinjiang has the largest desert in my country, the Taklimakan Desert, which has a harsh environment and is known as the "Sea of ​​Death". The Taklimakan Desert is located in the center of the Tarim Basin in southern Xinjiang. It is about 1,000 kilometers long from east to west and about 400 kilometers wide from north to south, covering an area of ​​330,000 square kilometers. The average annual precipitation is less than 100 mm, with a minimum of only 4 mm, while the average evaporation is as high as 2,500 mm to 3,400 mm.

Hotan Prefecture in Xinjiang borders the Taklimakan Desert to the north, and 2/3 of the 365 days of the year are sandstorms. There is a saying that goes: "If you don't eat enough sand during the day, you will eat an extra pound of sand when you sleep at night."

So, how are deserts formed? At first, gravel from the mountains is constantly polished and turned into smaller gravel, and then the wind forms sand ripples. As the wind increases, large sand dunes are gradually formed, and the highest sand dunes can reach 100 to 200 meters. Finally, the sand dunes continue to connect, forming a desert.

Desert scenery at the N39° Desert Tourist Area in Maigaiti County, Kashgar Prefecture, Xinjiang. (Photo from Xinhua News Agency)

During this expedition, we entered the core area of ​​the desert and drilled a 1,300-meter deep well. Why drill deep wells? To find out when the Taklimakan Desert was formed. This deep well goes from the surface of the desert to the bedrock beneath the desert. We can find the sand and gravel deposited in the desert at different ages, and analyze how the environment has evolved.

Research shows that there are three historical periods when the environment of the Taklimakan Desert has undergone major changes, which are 5.3 million years ago, 2.6 million years ago and 0.3 million years ago. Some major events have occurred during these historical periods. These events are directly related to the uplift of the Qinghai-Tibet Plateau, that is, the formation of the Himalayas and the Kunlun Mountains, which blocked the water vapor of the Indian Ocean. Therefore, the formation of the Taklimakan Desert is related to my country's geological history.

From the perspective of desert landscape, the Taklimakan Desert was formed about 300,000 years ago, which is also a conclusion we reached during this scientific expedition. Deserts are divided into three types: one is grid-shaped sand dunes, one is crescent-shaped sand dunes, and one is comprehensive longitudinal sand dunes. We conducted wind tunnel experiments in the desert and conducted real simulations, and found that the sand dunes in the Taklimakan Desert are constantly moving. During the second Xinjiang scientific expedition in the 1980s, Mr. Peng Jiamu once led the scientific expedition team to Lop Nur for an investigation, but he disappeared in search of water. At that time, we sent a large amount of manpower and material resources to find him, but we couldn't find him after a week. This is also related to the very fast movement speed of the sand dunes in the Taklimakan Desert.

The main hazards of the desert are as follows: First, it will have a significant impact on roads and railways, such as burying roads and railways; second, the pollution caused by sandstorms is also very serious. For example, there are more than 200 days of sandstorms in Hotan area a year, which has a great impact on human health, agricultural production and urban environment.

During the Xinjiang expedition, we encountered many sandstorms. When the sandstorm came, we could not see anything on the road, only a black mass rolling over. If you have no place to hide at this time, you may be buried by the big sandstorm, which is very dangerous. Therefore, when our expedition vehicles enter the no-man's land, they must bring satellite phones in case of emergency. Moreover, once an accident occurs, the team members cannot run around in the desert area, but can only hide in the car or in the tent and wait for rescue.

Of course, deserts also have a lot of value. On the one hand, deserts are important oil and gas gathering places in my country, and the Taklimakan Desert is also a key area for oil development in my country. At the same time, deserts are also very attractive tourist attractions. At present, Xinjiang is developing a railway around the Tarim Basin. After the entire line is opened to traffic, everyone can take a train along the Taklimakan Desert and appreciate different desert landscapes.

"Why "large mines do not cross national borders""

Xinjiang's unique geological structure and advantageous mineralization geological conditions have created rich mineral resources.

Xinjiang is a mineralized region formed by two major plates: the Tethys Plate and the Central Asian accretionary orogenic belt. These two plates converge in Central Asia, making Xinjiang and Central Asia a region rich in mineral resources.

However, there is a very strange phenomenon in this region, that is, "large mines do not cross the national border." What does "large mines do not cross the national border" mean? In Xinjiang, we have not found any super-large mines or mining areas, but there are super-large mines in Kazakhstan, Uzbekistan, and Kyrgyzstan.

Why does such a phenomenon occur? This has always been a big problem that the academic community wants to solve. In response to this problem, our country has carried out a lot of research work, discovered the mechanism of geological mineralization in Xinjiang, and proposed the theory of mountain bend structure.

This theory demonstrates in detail why large mines appear in other areas of Central Asia rather than in Xinjiang: on the one hand, the mountain bend structure makes the mineralization belt in the bend area mainly distributed in other parts of Central Asia. On the other hand, the collision of continental plates has caused the mining areas in Xinjiang to enter the deep, so there are relatively few areas with outcropping mines. This geological and mineralization research has laid a solid foundation for our prospecting in Xinjiang.

The most valuable thing about this expedition is the discovery of oil-rich coal. What is oil-rich coal? In a broad sense, coal resources with a tar yield of more than 7% are collectively referred to as oil-rich coal. The tar yield of the oil-rich coal discovered in the Tuha Basin is close to 20%, which is one of the few concentrated oil-rich coal producing areas in the world. We preliminarily predict that the resource volume of this oil-rich coal can reach 55 billion tons, which can be said to be the "oil-rich coal" among oil-rich coals.

The traditional development and utilization of oil-rich coal is to form liquid fuel and produce chemical raw materials such as olefins and ammonia through gasification and pyrolysis technology. This time, through the research on oil-rich coal, we have explored a unique oil-rich coal deep processing industry chain that can improve the recovery rate of coal tar together with chemical experts.

The formation of this industrial chain can increase the utilization rate of oil-rich coal by an order of magnitude. It can generate three major categories of products: the first category is directly converted into gas, the second category is converted into raw materials for fine chemicals, and the third category is chemical materials such as hydrocarbons and benzene. It is expected that a trillion-yuan industrial chain will be formed in the Tuha Basin in the future, which will be a major breakthrough in the construction of my country's Xinjiang petrochemical base and coal chemical base.

In short, Xinjiang is no longer a remote area, but a core area and a hub of our country, and the frontier of western development. In the future, we will further conduct research on the carrying capacity of Xinjiang's resources and ecological environment.

We have collected a lot of data and information in the past few years. We will calculate how many people Xinjiang's resources can support, how large a scale of economic development it can support, and what kind of industrial layout it can support. At the same time, we will also clearly propose what should be done and what countermeasures should be taken for the protection of Xinjiang's ecological environment. We also look forward to the third Xinjiang scientific expedition to contribute to Xinjiang's high-quality development and the construction of a beautiful Xinjiang, and to add new vitality to Xinjiang's development.