The National Conference on Combating Desertification was held in Beijing. This is an important event eagerly awaited by the broad masses of cadres and people in the sand area, an important meeting of great concern to all walks of life, and of great significance to further promoting the cause of national defense and sand control in China.
Since the last national conference on desertification control was held for more than ten years, especially since the beginning of the new century, the CPC Central Committee and the State Council have taken a series of effective measures to comprehensively promote the cause of national defense and desertification control. It has achieved a net reduction in the area of desertified land in China, effectively improved the ecological conditions and agricultural and animal husbandry production conditions, promoted the adjustment of rural economic structure and the transformation of production methods, safeguarded national unity and border stability, made important contributions to the national ecological improvement, economic development and social progress, and embarked on a road to solve the desertification problem that is suitable for China's national conditions and has China characteristics. This is the result of the hard struggle of the people in the sand area and the vast number of sand control workers, and it is a great success of the principles and policies of the party and the state for ecological construction.
China is one of the countries with the most serious land desertification hazards in the world. China has 1.7397 million square kilometers of desertified land, accounting for nearly 1/5 of the national territory. The western region, ethnic minority areas and border areas are the main distribution areas of desertified land, which affects the production and life of nearly 400 million people in China, and desertification in some areas is still expanding. This basic national condition determines that desertification has always been an important issue that must be dealt with in the process of modernization in China, and it also determines that the work of preventing and controlling desertification has always been an important work related to the overall sustainable development of economy and society.
The cause of harmony is based on ecology. Promoting the cause of sand prevention and control in an all-round way is not only an urgent need to improve the quality of life of people in sand areas and build a new socialist countryside, but also an urgent need to enhance national unity and build a harmonious socialist society. This is not only an urgent need to maintain and expand the survival and development space of the Chinese nation and promote the sustainable development of China's economy and society, but also an urgent need to effectively implement the United Nations Convention to Combat Desertification and maintain global ecological security. We should fully understand the extreme importance of strengthening sand prevention and control from the perspective of protecting the survival and development foundation of the Chinese nation, promoting sustainable economic and social development, and building a harmonious socialist society. With a highly responsible attitude towards the country, the nation and future generations, we should put sand prevention and control in the strategic position of the country's economic and social development, and put it at the top of the economic and social development in the sand areas, earnestly shoulder the glorious mission entrusted by the times, and unremittingly push forward the cause of sand prevention and control.
In the new period, we must fully implement Scientific Outlook on Development, adhere to the policy of giving priority to prevention, scientific management and rational utilization, follow the laws of natural, economic and social development, and implement comprehensive, scientific and legal prevention and control. It is necessary to firmly establish the idea of long-term struggle, widely mobilize all social forces to participate, establish and consolidate the ecological security system in sandy areas with forest and grass vegetation as the main body, consolidate the achievements in the construction of governance areas as soon as possible, curb the trend of land desertification in the expansion areas as soon as possible, significantly improve the ecological situation in the vast sandy areas as soon as possible, and make greater contributions to building a new socialist countryside and building a harmonious socialist society.
In the historical process of national defense and sand control in China, a large number of advanced collectives and British model figures have emerged. They are loyal guardians of environmental protection and active advocates of ecological construction in China. Their tenacious struggle and dedication will inspire more people to join the cause of sand control. Let's use hard sweat and unremitting struggle to create a more harmonious and beautiful life and write a more magnificent chapter on sand prevention and control.
2. New ideas of desert control
China has more than 700,000 square kilometers of desert, 570,000 square kilometers of Gobi desert and 6.5438+0.5 million square kilometers of plateau desert, all of which are basically in the western region. Moreover, the desert is still expanding at a rate of more than 3,400 square kilometers per year, which has become the source of worries and disasters in our country. Transforming these deserts has always been the dream of several generations of mankind. However, due to factors such as insufficient financial investment and water resources constraints, little progress has been made in greening and sand control: local improvement, overall deterioration, and frequent sandstorms.
Recently, I read "A Good Strategy for Sand Control-Building a Desert" by "Little Citizen" in the forum of powerful countries, and I feel that "building a desert" is really a new idea for sand control. However, according to his article "gradually covering deserts with solar panels", although there are some benefits mentioned in the article, there are also some problems: for example, the cost is too high, and the generated electricity lacks the market. On the one hand, the current cost of solar power generation is still too high compared with thermal power and hydropower, and these deserts are all located in the west. The southeast coastal cities with large power demand are too far apart, and the transmission cost is too high, while the north has the advantage of thermal power.
In this regard, the author believes that it may be possible to cover sand control with cheap plastic woven cloth and plastic film-that is, cover it on the sand and hold it down with sandbags, so that the dust will not be blown away by the wind. Because on the one hand, "solar panels can gradually cover the desert" can greatly reduce the cost and improve the economic feasibility. On the other hand, compared with greening and sand control methods such as planting trees and grass, the advantage of covering sand control is that it is not limited by water resources, seedlings, planting time, etc., and can be built on a large scale day and night all year round (because plastic woven cloth, plastic film, etc. can be industrialized and mass-produced compared with seedlings to meet the needs of large-scale construction). At the same time, the effect is faster, because it takes time to plant trees and grass, and it is difficult to ensure that everyone can survive. In fact, due to the lack of water, the shelterbelts previously built by China in the Three North Areas are in danger of being destroyed.
Although covering sand control can not bring direct return to this project, considering that this project can promote employment (because it is a labor-intensive project) and stimulate economic growth; At the same time, it can reduce the harm caused by sandstorm invasion and desert expansion, and indirectly increase the output; In addition, it has created favorable conditions for gradual greening and western development. -when there is water or when necessary, it can be removed and re-greened, or used for industrial and agricultural development. It should be a public project, which has good social benefits and deserves the government's consideration.
Of course, the feasibility of covering sand control with cheap plastic woven cloth and plastic film needs further study: for example, how long the plastic film can resist "wind and sun", that is, how high the maintenance cost is, and which scheme is better than the one with high price and good resistance to "wind and sun". And can you find a cheap and weather-resistant cover? ! At the same time, it is necessary to compare in detail the short-term and long-term costs and short-term, long-term, direct and indirect benefits of green sand control methods such as covering sand control. If the comprehensive cost of covering sand control is too high, it may be difficult to implement, or it can only be mainly used in places that are really difficult to afforest sand control: flowing sand dunes lacking water, ancient lakes prone to sandstorms, saline-alkali land and so on. If it is only slightly higher than the greening sand control, considering the above benefits, the covering sand control project can be implemented. If the comprehensive cost of covering sand control is less than that of greening sand control, it is naturally more feasible.
But in fact, considering the limitation of water resources, it is difficult to permanently control the desert simply through large-scale greening. Therefore, even if the cost of covering sand control is high, it may become the only feasible scheme to eradicate desert harm in the future and has to be implemented.
Part II: Typical viewpoints and examples.
1. "Land desertification" and "land desertification" have different meanings. "Land desertification" is the result of both natural and human factors. The process is dominated by wind erosion of cultivated land and wind accumulation of grassland. The latter is based on the fact that the thickness of the sand layer covered by the surface is greater than 10 cm. Most of the accumulated aeolian sand comes from the surface materials in this area, that is, it belongs to "sand lifting in situ" Land desertification is a sign of environmental degradation and a positive feedback process of environmental instability. If fundamental measures are not taken, the process of land wind erosion and desertification will not stop automatically, but will intensify development. "Land desertification" refers to the environmental degradation process in which the fragile ecological balance is destroyed by excessive human activities in the arid and windy sandy surface environment, so that desert landscapes similar to sandstorm activities appear in the original non-desert areas, leading to the decline of land productivity. Desertification is an important ecological and environmental problem in the world at present, and it is also a prominent geological problem. The serious problem is that "global desertification is still spreading". China also has the problem of land desertification. Among the desertified land in China, there are 6,543,800 square kilometers of desertified land, 6,543,800 square kilometers of land with potential desertification risk and 6,543,800 square kilometers of aeolian sand in humid areas. More than 50 million people are affected by desertification, and nearly 4 million hectares of dry land and 5 million hectares of grassland are affected by desertification. In recent years, the area of desertified land in China has increased from 13.7 square kilometers to 17.6 square kilometers. Therefore, the erosion of land resources in China is also very serious.
2. Although ecological management is called for every year, and the state has invested a lot of manpower and material resources, the ecological environment in the sand area of western China is still deteriorating at an accelerated pace. Facing the increasingly serious ecological disaster, we should be alert from the concept of sand control.
Ecological "refugees" appear in the dust source. The ecological environment of Alashan League in Inner Mongolia Autonomous Region and Minqin County in Gansu Province, the source of severe sandstorms in northwest China, has been deteriorating continuously, and a group of local farmers and herdsmen have been forced to relocate and become ecological "refugees" after losing their production and living conditions.
Meng Gen Qiqige, 40, said helplessly in Mandela Sumu, Alashan Right Banner that more than 20 years ago, her family lived by herding camels in Tamusu town. Later, due to grassland degradation and desertification, her family's sheep soon decreased by more than 10, and a family of four could not make a living by grazing. With the help of the local government, she moved to Mandela Sumu to start farming, and now she has planted 30 acres of land. It is understood that in recent years, Mandela Sumu has successively accepted 140 ecological "refugees" from ecologically fragile areas in Alashan Right Banner, such as Meng Gen Zigejia.
There are two deserts in Alashan League, Badain Jaran and Tengger, with a total land area of about 270,000 square kilometers, of which more than 80% is desertification. Under the strong north wind, in recent years, the mobile sand dunes in the Badain Jaran Desert have invaded south at an average annual rate of 20 meters, and the local quicksand belt has "shaken hands" with the southwest edge of the Tengger Desert. According to the national forestry department through satellite monitoring and ground investigation, three new quicksand belts have appeared between the two deserts. With the further deterioration of the local ecological environment and the intensification of wind and drought disasters, the desertification land in Alashan League is expanding at an area of 1 10,000 square kilometers per year.
In Minqin County, Gansu Province, another major birthplace of severe sandstorms in northwest China, due to the decrease of incoming water in the upper reaches of Shiyang River year by year and the over-exploitation of groundwater, the forest and grass on the surface died and the land was desertified, and a large number of farmers were forced to live in different places. The Qingtu Lake area in the north has become a channel for large-scale invasion of oases by deserts. The quicksand advances 8- 10 meters every year. During the period of 10, the outflow population reached 32,000, and only a few families were left in some villages. Due to water shortage and sand damage, more than half of the 440,000 mu of farmland is abandoned.
3. In southern Xinjiang, the ecological disaster in the lower reaches of the Tarim River continues, and the Taklimakan Desert and the Kumutage Desert have "shaken hands" in many places. Local cadres and the masses are worried that if the two deserts finally meet and close, resulting in the disappearance of the green corridor in the lower reaches of the Tarim River, it will cause more serious ecological disasters and social problems such as large oases being annihilated by sandstorms and internal and external traffic jams.
What is even more worrying is that if the two deserts meet, a 300-kilometer-long green corridor composed of natural desert Populus euphratica forest and shrub forest in the lower reaches of Tarim River will disappear. Not only the national highway 2 18, the second channel connecting Xinjiang with the mainland, will be completely blocked, but also Korla, the capital of Bazhou and an important town in southern Xinjiang, will be surrounded by desert, which will further make the rich mineral resources in Tarim Basin and Altun Mountain lose their support for development.
Tarim River is the largest inland river in China, with a total length of 1, 32 1km. It is not only the mother river of millions of people of all ethnic groups in southern Xinjiang, but also the ecological river to prevent the desert from invading the oasis. Due to long-term unreasonable development and utilization and climate change, since 1972, the 363-kilometer-long river below Daxihaizi Reservoir in the lower reaches of Tarim River has been cut off for a long time, the tail taitema lake has dried up, coastal trees have withered and died in a large area, and Taklimakan Desert and Kumutage Desert have been attacked from east to west, which has aggravated land desertification.
According to the information provided by Bazhou Forestry Bureau, over the past decades, due to the obvious weakening of the ecological regulation function of Tarim River, 60% of the natural Populus euphratica forests and 40% of the shrubs in the lower reaches withered and declined due to lack of water, and more than 4 million mu of grassland was degraded. Dozens of places on the 2 18 national highway are often covered by quicksand, and some people in some areas have lost their homes.
The key to curb the further deterioration of ecological environment in the lower reaches of Tarim River is to ensure ecological water use. Since 2000, the state and the government of Xinjiang Uygur Autonomous Region have launched the recent comprehensive management plan of Tarim River Basin, and transferred water from Bosten Lake to the lower reaches of Tarim River for six times, which has played a certain role in improving the ecological environment, restoring vegetation and protecting green corridors in the lower reaches of Tarim River. However, due to the accumulation of ecological disasters, the expected scene of "blue waves rippling, dead trees meet spring" did not appear in the lower reaches of Tarim River.
Picked up sesame seeds and lost watermelon. According to the survey, although the state has invested a lot of money in afforestation, the ecology in some areas has improved, but a large area of natural desert forests has been destroyed, which has aggravated the fragile ecology in northwest China. Local cadres and the masses vividly said that returning farmland to forests is lighter than enclosure, and "sesame seeds" were picked up and "watermelons" were thrown away.
-Natural desert forests have been severely damaged.
Qiemo County, Xinjiang, located at the southeast edge of Taklimakan Desert, has planted 6.5438+0.8 million mu of trees since 1980s, which has provided a good ecological guarantee for agricultural production in the county. However, due to the dual influence of nature and traditional habits, local farmers and herdsmen still maintain the original lifestyle of chopping wood and firewood, which has caused serious damage to natural desert forests. Natural desert forest ecosystem belongs to the most fragile forest ecosystem in the world. It takes thousands of years for its self-succession and formation, but only a few years for the destruction of mankind.
Facing the increasingly serious wind and sand hazards, Qira County has fenced off 480,000 mu of natural desert forest. The reporter saw at the scene that natural red willows and wild reeds have grown to a height of 1 meter. Ranger's monthly salary 150 yuan has no source to solve.
-The investment in artificial afforestation is high, and the benefit of afforestation by closing sand is good.
In the investigation, the reporter found that the cost of artificial afforestation in the northwest sandstorm area is amazing. However, artificial afforestation is supported by state funds, and the task of natural desert forest enclosure is small, so it is often difficult to get funds in place.
Kule Ecological Management Zone in Postan City, Mo Yuxian is located on the vast Gobi Desert, and the local people planted 6,543,800+0.2 million mu with the support of state funds. Zhang Zhennian, director of the county forestry bureau, said that the cost of saplings alone is as high as 200 yuan, and it costs 600~800 yuan to afforest an acre of land, plus land preparation, pit digging, well drilling and water conservancy canal system. Zhang Zhennian said frankly: "The Woods on the Gobi Desert are hard to feed."
In Cele, Qiemo, Ruoqiang and other counties on the southern edge of the Taklimakan Desert in southern Xinjiang, it was learned that under the condition of harsh local natural environment and prominent contradiction between ecological water and agricultural production and domestic water, drip irrigation technology had to be adopted in the construction of artificial shelter forest, and drip irrigation afforestation not only had high investment cost, but also required long-term investment in later management and protection. Although some places have caused forests, they are unable to manage them, and then they have a huge "burden".
4. To curb land desertification, we must give priority to prevention, give consideration to both prevention and control, and combine prevention with prevention.
On May 20th, at the seminar on "Water and Desertification" held by these organizations all over the country, a person in charge of the Desertification Control Office of the State Forestry Administration made a speech on the present situation and countermeasures of land desertification. He said that at present, in addition to natural factors, the main human factors causing land desertification in China are "five abuses", namely, indiscriminate reclamation, deforestation, overgrazing, indiscriminate exploitation and abuse of water resources. To curb the expanding trend of land desertification, we must do a good job in prevention. "Prevention" is first embodied in strengthening the management of "five evils" and putting an end to man-made destructive factors.
First, we should prevent blind reclamation. Overexploitation is the main reason of land desertification in China. Since 1950s, China has carried out four large-scale land reclamation, with grassland reclamation reaching 208 million mu, of which 654.38+0 billion mu has been reclaimed as sandy land. From 1994 to 1999, the cultivated land on fixed sandy land and grassland in China reached170,000 square kilometers, of which about 50% became mobile and semi-fixed sandy land.
Second, livestock should be determined by grass. At present, the grazing of most grasslands in China greatly exceeds its carrying capacity. The theoretical carrying capacity of grassland in China is 450 million sheep units. By the end of 1997, the number of large livestock in China had reached1400,000, with 260 million sheep, equivalent to 860 million sheep units, nearly doubling.
Third, the cutting of firewood should be controlled. Deforestation and excessive felling have always been the enemy of vegetation in sandy area, which not only directly reduces the coverage area of forest and grass, but also destroys the harmonious forest and grass environment. From 1994 to 1999, 600 hectares of sandy vegetation were destroyed by firewood harvesting in Shazhuyu Township, * * County, Qinghai Province, and 3,800 hectares of natural desert forests dominated by Populus euphratica and Populus euphratica were destroyed by firewood harvesting in Hotan area, Xinjiang.
Fourth, indiscriminate mining and digging are strictly prohibited. From 1994 to 1999, the grassland destroyed by Tricholoma matsutake in Inner Mongolia reached1950,000 mu, of which more than 60 million mu had been desertified. Only one coal field development in Yulin, Shaanxi Province destroyed 260,000 mu of vegetation and desertified 300,000 mu of land. In the past two years, the state has promulgated laws and regulations, and Nostoc commune has been controlled to a certain extent through law enforcement, but the phenomenon of indiscriminate collection of Chinese herbal medicines and destruction of vegetation is still very prominent.
Fifth, we should strengthen the management of water resources. Irrational use of water resources leads to land desertification, which is very common. Since 1950s, the upper reaches of Tarim River Basin in Xinjiang have continuously exceeded the standard water consumption, resulting in 270 kilometers of river cut off in the lower reaches, 5.3 million mu of Populus euphratica forest died, 6.5438 million mu of grassland was degraded, and 250,000 mu of farmland was forced to be abandoned.
The person in charge also stressed that there are many factors that cause land desertification and ecological deterioration. Therefore, comprehensive management should be emphasized in the management of desertification land. We should act in accordance with the natural laws of plant succession, take the restoration of forest and grass vegetation in sandy areas as the core, take a multi-pronged approach, comprehensively apply forestry measures, agriculture and animal husbandry measures and water conservancy measures, and implement afforestation and grass planting, returning farmland to forests and returning grazing to forests according to local conditions; We should vigorously promote conservation tillage, no-tillage and crop stubble in cultivated land. As for water resources, it is necessary to develop and utilize them reasonably, and combine open source with throttling. In addition to ensuring the necessary industrial water and people's living water, we should also focus on ensuring ecological water. The Beijing-Tianjin sandstorm source control project covering more than 90% of the desertified land in China and the fourth phase of the Three North Project have comprehensively considered the prevention of disasters and the sub-regional policy, and the progress is smooth and the effect is obvious.
In view of the current practical problems, the person in charge suggested that the state should implement four policies as soon as possible: first, contract all grasslands to households as soon as possible, and resolutely change the situation that livestock eat large pots of grass; Second, state-owned barren hills and wasteland should be provided free of charge to those who plant trees and grass. Implement the policy of "whoever makes the plant owns it" and allow inheritance, transfer and auction; Third, afforestation in barren hills, deserts and wasteland is exempt from any taxes and fees; The fourth is to reduce or exempt business tax for forest products and livestock products processing industry.