Desertification area in China and other desert-related contents (not less than 300 words)

Present situation, harm and causes of desertification in China

43% of the land on the earth's surface is distributed in arid areas, and more than 65,438+065,438+00 countries suffer from land desertification, resulting in huge losses of $42 billion worldwide every year. China is one of the countries most affected by desertification in the world. First, the area is large and widely distributed. According to the results of the second monitoring of desertified land by the State Forestry Administration, by the end of 1999, the area of desertified land in China had reached17.43 million square kilometers, accounting for 18% of the national territory, involving 84 1 county (flag) in 30 provinces (autonomous regions and municipalities). Eight deserts and four sandy lands are the main sand sources in China, and there are also scattered sandy lands along the river, river and sea in the south. China has a mobile sand dune area of 427,200 square kilometers, fixed and semi-fixed sand land of 463,000 square kilometers, Gobi and wind erosion land of 7 1. 1.404 million square kilometers, and others 1.4 1.400 square kilometers. A sandstorm belt with a length of about 4,500 kilometers and a width of about 600 kilometers is formed in the northwest, north China and northeast China. It starts from the Tarim Basin in the west and reaches the west of Songnen Plain in the east, endangering most areas in the north. Second, the expansion speed is fast and the development situation is grim. According to dynamic observation, in 1970s, land desertification in China spread at the rate of 1.56 square kilometers per year; in 1980s, it was 2 1.00 square kilometers; in 1990s, it reached 2,460 square kilometers; in the early 20th century, it reached 3,436 square kilometers, which was equivalent to losing the land area of a medium-sized county every year.

The harm of land desertification. Desertification is a major environmental and social problem facing human beings in the world today, and it is a cancer of the earth, and its harm to China is also very alarming.

-The space for the survival and development of the Chinese nation has shrunk. The area of desertified land in China is equivalent to the area of Guangdong province 10, and the new area in five years is equivalent to the total area of Beijing. The population of China is increasing by140,000 every year, while the cultivated land is decreasing year by year. Since the founding of New China,100000 mu of cultivated land, 35.25 million mu of grassland and 95.85 million mu of forest land have become mobile sandy land. The sandstorm is approaching, and 24,000 towns and villages are endangered, so that tens of thousands of farmers and herdsmen are forced to become ecological refugees, and some towns and villages are forced to relocate many times. 85% of the land in Alxa League, Inner Mongolia has been desertified, and it is expanding at the rate of 6.5438+0.5 million mu per year. It is not alarmist to predict that Ejina Oasis will become the second Lop Nur in 50 years. As one of the sources of sandstorms in Beijing, the area of quicksand in Hunshandake Sandy Land increased by 93% in 7 years and 9 1% in Bashang area in 9 years.

-leading to a serious decline in land productivity. According to the calculation of Lanzhou Desert of Chinese Academy of Sciences, the annual wind erosion loss in China is equivalent to 270 million tons of chemical fertilizer, which is equivalent to several times the national agricultural chemical fertilizer output. Desertification has degraded 2.07 billion mu of grassland in China, accounting for 60% of grassland area in sandy areas, and raised nearly 50 million sheep every year; Cultivated land degraded by 65438+160,000 mu, accounting for 40% of the cultivated land area in the sandy area. Cultivated land in desertification areas, in some places, yields tens of kilograms per mu, which requires multiple sowing and cultivation.

-causing serious economic losses. According to the evaluation of desertification in economical loss, the direct economic loss caused by desertification in China reaches 54 billion yuan every year, which is equivalent to several times the fiscal revenue of several provinces in northwest China. 1in may, 1993, a serious sandstorm occurred in northwest China, and 72 counties (banners) in Xinjiang, Gansu, Ningxia and inner Mongolia were affected, killing 1 16 people, losing120,000 heads of livestock, affecting 5 million mu of crops and causing direct economic losses of more than 400 million yuan. There are 10 1 national poverty-stricken counties in the sandy area, accounting for 17% of the 592 poverty-stricken counties in China.

-aggravated the deterioration of the ecological environment. Of the 65.438+0.6 billion tons of sediment imported into the Yellow River every year in China, 65.438+0.2 billion tons come from desertification areas, and the Kaifeng section of the Yellow River has become a "suspended river" due to serious soil erosion. There are frequent sandstorms in China, 8 times in 1960s, 3 times in 1970s/kloc-0, 4 times in 1980s/kloc-0 and 23 times in 1990s. The increase of atmospheric dust, the aggravation of air pollution, the decline of environmental quality, the sandstorm in the northern cities and the mud rain in the south have affected South Korea and Japan, attracting domestic and international attention and becoming the topic of eco-environmental diplomacy.

Causes of land desertification. The result of the interaction between natural factors and human activities. The lack of precipitation and sparse vegetation in northern China, coupled with global warming and persistent drought and lack of rain, aggravated land desertification. However, the pressure of population growth on ecological environment capacity and human factors such as "five abuses" are the fundamental reasons for the expansion of land desertification.

One is overgrazing. According to statistics, the overload rate of livestock in sandy grassland in China is 50- 120%, and it is as high as 300% in some areas, which leads to the serious "three modernizations" of grassland. The yield per mu of grassland in Inner Mongolia decreased from 109 kg in the 1960s to 43 kg in the 1980s, and the place where "the wind blows grass, cattle and sheep are low" has become a "rat's back". 10.9% (1152,000 square kilometers) of grassland desertification and degradation in the monitoring area of State Forestry Administration in 1999 were caused by overload and overgrazing.

The second is deforestation. Due to deforestation, land desertification in some areas is very serious. In Hotan area of Xinjiang, 57,000 mu of Populus euphratica, Populus euphratica and other natural desert forests were destroyed due to firewood harvesting in five years, and 30 million mu of original sand-fixing vegetation in Qaidam Basin of Qinghai Province. In the mid-1980s, 65,438+0/3 of the land was desertified due to logging. There are only 300,000 mu of natural Haloxylon ammodendron forest in the northwest of Salt Lake in Lantai Town, Inner Mongolia, and half of the 56,000 mu of salt mine has been buried by quicksand.

The third is digging. The phenomenon of destroying vegetation, such as digging Chinese herbal medicines, throwing seaweed and digging indiscriminately, is very prominent in the sand area. There are 654.38+ten thousand farmers and herdsmen entering Alashan League every year, and the grassland area destroyed by this phenomenon in Inner Mongolia reaches195 million mu, of which 60 million mu has been desertified. Because of coal field development, 260,000 mu of vegetation in Yulin, Shaanxi Province was destroyed and the land was desertified. Gansu province destroyed 5.02 million mu of grassland in five years because of digging licorice;

The fourth is indiscriminate planting. 1994- 1999 China's fixed sandy land and grassland have an area of10.7 million square kilometers, with an average annual reclamation of 3,400 square kilometers, about half of which become mobile and semi-fixed sandy land. The local people said sadly, "one year to open grasslands, two years to distribute grain, and three years to change sand beams";

Fifth, the disorderly use of water resources. Upstream interception, flooding, waste of water resources, land salinization, downstream water shortage, and desert vegetation death. The Tarim River and its downstream were cut off for 270 kilometers, and 5.3 million mu of Populus euphratica forest died. The amount of water flowing from Heihe River into Inner Mongolia Oasis dropped from 900 million cubic meters to 200 million cubic meters, the Juyan Sea in the east and west dried up, 65.438+0.4 million mu of Haloxylon ammodendron forest died, and desertification intensified. In Minqin Oasis, due to the large-scale exploitation of groundwater, the groundwater level dropped sharply, a large area of sandy vegetation dried up and died, and sand dunes were activated.

Experiences and lessons of sand prevention and control abroad and the course of national defense and sand control in China.

Countermeasures for national defense and sand prevention in junior middle schools in the new century

The countermeasures for China's national defense and sand control in the new period are: following the principle of "protection first, comprehensive management and people-oriented"; Constructing three barriers to curb land desertification; Clarify the responsibility goal and make a breakthrough in regional governance; Solve six problems and introduce policies and measures; Improve the six systems and management methods; Sand control project management, project responsibility to people.

(1) Build three barriers to curb land desertification.

The eight deserts and four sandy lands in China are natural landscapes. Sand control is not to plant trees in Gobi desert or desert, but to curb the expanding trend of desertification and control it in certain surrounding areas. It is a long-term process for sand blowing and sandstorm to appear in China, but it is possible to curb land desertification through sand fixation by forest and grass organisms.

The first is to protect the existing sandy vegetation and desert vegetation. Desert vegetation is the main component of maintaining desert ecosystem, which is easy to be destroyed and difficult to recover. Therefore, we should put the protection of desert vegetation in the first place, otherwise all the management and afforestation will be in vain. The soil consolidation function of Populus euphratica forest in the desert is very obvious, and it is hundreds or thousands of years old. Salix psammophila, Haloxylon ammodendron, elm, Caragana korshinskii and Hippophae rhamnoides are also good sand-resistant tree species, which must be protected. Without the maintenance of desert vegetation, the effect of sand control will be greatly reduced. Therefore, it is necessary to speed up the demarcation of primary desert closed protection areas, desert wildlife nature reserves and national desert (psammophyte) parks, and protect them according to law. Take strong vegetation protection measures in accordance with the law, prohibit indiscriminate reclamation, grazing, mining, cutting and other destructive acts, and protect the existing vegetation in the sand area; Measures such as fixing livestock with grass, improving varieties and keeping in captivity will restore and improve the production and ecological functions of grassland; Take strict water resources management measures to improve the utilization rate of water resources and realize the rational distribution and coordinated utilization of domestic, production and ecological water.

The second is to build a large windbreak and sand-fixing forest and grass belt along the eight deserts and four sandy lands due to damage. Establish a large area of sand-fixing shelterbelt between desert and oasis according to law. Around the sandstorm belt, which is 4500 kilometers long and 600 kilometers wide from east to west, the government should make overall planning, implement it step by step, set aside plots and organize the masses to implement it year by year.

Third, the construction of farmland forest network and the conversion of desertified farmland into forests. Consolidate oasis and densify farmland forest network in farming-pastoral ecotone; For arid cultivated land with serious sandstorm damage, measures such as no-tillage method, "root-keeping" cultivation and expanding winter wheat area should be popularized to reduce sandstorm disaster; Returning farmland to forest and grassland in desertified farmland, choosing varieties and modes of planting trees and grass, promoting national ecological goals, increasing farmers' income and getting rich, and coordinating regional economic development.

(B) people-oriented, innovative ideas. On the basis that the county's financial resources are insufficient 1000 yuan/year and the people's income is insufficient 1000 yuan/year, it is difficult for China to engage in the great cause of ecological construction. Some experts pointed out through monitoring and analysis that 5% of the land desertification in China is caused by drought and 95% by human factors, among which "five abuses" are the main reasons, such as over-cultivation, grazing, mining, excavation and improper utilization of water resources. However, these are all appearances, and the core problems are the population capacity of the environment, overpopulation and excessive consumption of natural resources by survival and development. In order to solve this problem, we should advocate people-oriented and harmonious coexistence between man and nature, consider the survival and development of the masses when formulating national policies, and explore innovative ideas according to the sustainable development strategy of coordinating people, resources and environment.

First, encourage relevant departments to increase the construction of basic farmland and grassland in existing sand areas and increase the output per unit area. Support the agricultural sector to propose grassland construction, banning grazing or increasing farmland construction.

Second, the implementation of closing hillsides (sand) for afforestation should solve the energy and fuel problems in rural areas. Relevant state departments are conducting pilot research on rural energy construction projects, and biogas digesters can be developed in southern China. The construction of biogas digesters is four in one, with an average of more than 4,000 yuan per pool, and the state subsidizes about 1000 yuan per household, thus avoiding firewood burning. At the same time, the northern region can develop wind power generation and solar energy utilization.

Third, individual areas can migrate ecologically to achieve the purpose of closing hillsides for greening. The alpine, alpine and remote areas which are not suitable for production and life, such as fragile ecology, inconvenient transportation and serious endemic diseases, should be moved in an organized and planned way. The government demarcates basic farmland and subsidizes housing construction, and the state subsidizes about 25,000 per household. Grassroots units are allowed to concentrate limited funds, including closing hillsides for afforestation, poverty alleviation, grain subsidies for returning farmland to forests, and closing hillsides for greening by ecological immigrants.

Fourth, encourage the masses to keep the basic grain ration fields, increase investment, increase the output per unit area, and lay the foundation for other desertified cultivated land to increase returning farmland to forests.

Fifth, the national ecological goal should be organically combined with the increase of people's income and the development of regional economy, and forestry and ecological construction must find this combination point. For a long time, the purpose of afforestation work is not strong, and this view must be changed. Afforestation should be linked with the macro-ecological goal of China, and combined with increasing people's income, increasing enterprise benefits and increasing government taxes. Therefore, the ecological construction should first choose varieties and models, and develop some tree species and grass species suitable for local ecological and economic benefits. Seabuckthorn, Caragana korshinskii, Haloxylon ammodendron (inoculated with Dayun), Glycyrrhiza uralensis and other varieties and some intercropping patterns have achieved good results. In Siziwangqi, Wumeng, Inner Mongolia, people used to grow grain on sandy farmland, and the annual net income per hectare was less than 150 yuan. Moreover, due to the harm of sandstorms, it had to be replayed several times. Now Caragana korshinskii is planted on the sandy land, and the net income per hectare reaches10.5 million yuan. The forest medicine model and forest fruit model also have good effects. The model of "company+base+farmer" is very promising. As long as a county can select one or two projects correctly, under the pull of the whole industry, ecological construction can make a leap and people's economic income can be greatly improved. At present, the people in the sand area are still very poor, and it is far from enough to rely on one household to carry out ecological construction. It must be developed on a large scale under the guidance of the government, and finally realize the organic combination of ecological construction and people's income increase.

(3) Clarify the responsibility objectives and make breakthroughs in regional governance.

The State Council's National Ecological Environment Construction Plan requires that by 2003, the land area for desertification control will be 96,000 square kilometers, 2010,220,000 square kilometers and 201-20,304,000 square kilometers. The Draft National Plan for Desertification Prevention and Control puts forward that the short-term goal is to basically curb the trend of continued expansion of desertified land by 20 10. The medium and long-term goal is that by 2030, on the basis of consolidating the existing achievements, the ecological environment will be further improved and the ecological system will be initially formed; By 2050, it is necessary to build a relatively complete ecological system in the sand area, scientifically and rationally utilize the resources in the sand area, and coordinate the development of ecology and economy. To achieve this goal, the task is very arduous. It is necessary to decompose tasks into provinces, prefectures and counties, and establish a target responsibility system for assessment at different levels. At the same time, the work guidance should be easy before difficult, focusing on different demonstration sites and governance models of different types of districts, establishing a responsibility system for the objectives of the leadership term, determining the governance objectives in stages, grasping the phased results, further strengthening the monitoring and evaluation of desertification, and giving local governments leadership power, responsibility and pressure.

According to sand control experts, China's sand control division is divided into five areas, and five key projects are arranged for control, forming a national sand control pattern.

-arid desert edge and oasis type area. There are seven deserts to the west of Helan Mountain and to the north of Qilian Mountain and Altun Mountain, with annual precipitation below 200 mm, drought and little rain, sparse vegetation, and desert, Gobi and oasis alternately distributed.

-Semi-arid and semi-humid land types. To the east of Helan Mountain, to the north of the Great Wall and to the west of the northeast, there are four sandy lands with annual rainfall of 200-400 mm, dry and windy, sparse vegetation and abundant water resources.

-Plateau alpine desertification land type area. The alpine region of the Qinghai-Tibet Plateau is over 3000 meters above sea level, with precipitation 100-300, sparse vegetation and fragile ecology.

—— Semi-humid and humid sandy land types in Huang-Huai-Hai Plain. The alluvial plains such as the old course of the Yellow River have good hydrothermal conditions, with an annual rainfall of 500-800 mm.

-South wet sandy land type area. Sandy land is distributed along the southern river, river and sea, with annual rainfall of 600- 1200mm, high temperature and lack of fertilizer.

The climate, geographical conditions, present situation and characteristics of water and fertilizer fields in different types of areas are different, and the main attack direction and control countermeasures are also different. The layout of national or regional key projects can achieve remarkable results.

-Sand control projects around Beijing. Focusing on most of the second-class areas, the ten-year plan covers an area of 458,000 square kilometers, and the scope of the project includes 75 counties in 5 provinces, autonomous regions and municipalities with a total investment of 56.8 billion yuan.

-the fourth phase of the Three-North Shelterbelt Project. Focusing on the first, second and third class areas, the ten-year planning area is 4 million square kilometers, and the project scope includes 590 counties in 14 provinces, autonomous regions and municipalities, with a total investment of 35.4 billion yuan.

-Comprehensive control project of desertification land in Tibet's "one river and two rivers" area and ecological construction project of desertification land control in Hotan area of Xinjiang. Belonging to the third and first category areas, desertification is serious, and it is difficult to fundamentally improve without increasing control efforts. The planning of sand control project in Tibet covers 28 counties with a total investment of1364.38+0.8 billion yuan. The ecological construction project in Hotan, Xinjiang covers an area of 25,000 square kilometers. The scope of the project includes 1 1 county (regiment, farm) with a total investment of 19 1 100 million yuan.

-Comprehensive control project of desertified land in the old course of the Yellow River. The planned management area of the project is 76,500 square kilometers, and the construction scope includes 3 provinces and 85 counties, with a total investment of 654.38+0.6 billion yuan.

-Demonstration Project of Desertification Control in Southern Wetland of China. The scope of pilot demonstration construction is 14 provinces and 232 counties.

(four) the management of sand control projects, the project responsibility to people.

At present, the state has invested a lot of money and food in ecological construction, but some local people complain that the quality of the project is poor, the money and food are not in place, and there are many problems in the "tofu residue" project. We must strengthen project management in the spirit of being responsible to the party and the people.

The first is to implement the local government project management responsibility system. The tasks, objectives, responsibilities, money and food are implemented in the province, and the administrative target responsibility system is implemented in the form of a letter of responsibility to the provinces, prefectures, counties, townships, villages and farmers, and strict inspection and assessment are carried out.

The second is to strengthen project quality and fund management. The implementation of two hooks, that is, when arranging the production task, it is linked to money and grain, and when paying grain, it is linked to the completion of qualified area. Do a good job in planning and design and seedling supply. The development of forests through science and technology should be embodied in planning and design. Do a good job in the management of inspection and acceptance and reimbursement system, and establish an inspection and acceptance system of national verification, provincial review and county-level comprehensive self-examination. The results of inspection and acceptance at the county level are used as the basis of reimbursement system, and the inspection results at or above the county level are used as the basis for regulating investment and rewarding and punishing.

Third, three responsible persons are in place. The responsibility system of administrative leaders, especially the responsibility of county heads, should be clear; Technical person in charge system, agriculture, forestry, water conservancy, planning commission, finance, food and other relevant departments, should be responsible; It is necessary to establish the system of the person in charge of the project, that is, the person in charge of the farmers, to prevent the masses from managing the life of planting, and also to ask the state to give money and food subsidies. In a word, our sand control technology has reached the standard. As long as the responsibility system is established in project management, two important links and three responsible persons are in place, there is full hope to do a good job in sand control and ecological construction projects.

(5) Improve the six systems and management methods.

First, improve the organizational leadership and management system. From the central government to the provinces, prefectures, counties and townships, a coordination or leading group for sand prevention and control should be established, with its office located in the Ministry of Forestry. The forestry departments of 13 provinces, prefectures and counties with serious desertification have established administrative departments and desertification monitoring centers (stations);

The second is to improve the policy system. Policies and regulations supporting this law will be promulgated as soon as possible. Establish policies and mechanisms that meet the needs of the project and are conducive to encouraging non-public ownership to participate in sand control, such as financial support, tax incentives, land use policies, and protecting the legitimate rights and interests of managers;

The third is to improve the scientific and technological support and technology promotion system. Formulate standards, regulations, rules and measures to prevent and control desertification, vigorously popularize advanced technologies and scientific research achievements, strengthen supporting projects for scientific and technological research, establish a technical grading training system, and do a good job in supporting the construction of scientific and technological organizations;

Fourth, establish a national, provincial and county-level desertification monitoring and early warning system, implement effective monitoring and implement a regular notification system;

Fifth, improve the law enforcement system, realize desertification control according to law, and do a good job in publicizing and enforcing the Law on Combating Desertification and the United Nations Convention to Combat Desertification.

Sixth, implement the international cooperation system for desertification control. Through the communication and publicity between the secretariat of China Implementation Committee and the secretariats of United Nations conventions, international organizations and developed countries, we will actively seek cooperation mechanisms to attract foreign investment and broaden the fields of sand control technology, policies and cooperation at home and abroad.

(six) to study six issues and introduce policies and measures.

First, it is necessary to establish the awareness that desertification control should be promoted simultaneously with economic development and social progress, and solve the status problem of desertification control in the whole national development strategy from the perspective of social and economic sustainable development;

Second, according to the requirements of priorities, scientifically divide the desertified land in the whole country, and solve the strategic layout problem of desertification control from the macro-division of national economy and ecology;

Third, it is necessary to analyze the deep-seated reasons leading to the "five evils", start with the root causes of land desertification, and solve the strategic measures to prevent and control desertification;

Fourth, follow the principle of material interests, start with the policy mechanism of mobilizing the masses to participate extensively, and solve the dynamic problem of sand prevention and control;

Fifth, it is necessary to form a mechanism of responsibility for defending the land, punishment for losing the land, and rewarding the excellent land, so as to solve the responsibility problem of sand prevention and control from the formulation of the performance evaluation index system of government officials;

Sixth, according to the requirements of the market economic system, we should start with speeding up the economic reform and industrial structure adjustment in the sand area to solve the problems of economic development and farmers and herdsmen getting rich. In view of the new situation, study new problems, introduce new methods and achieve new breakthroughs.

Our national defense and desertification control work is arduous, lofty and great. The broad masses of cadres and people on the sand control front are determined and confident. Under the leadership of the CPC Central Committee and the State Council, they will work hard, fulfill their duties and accomplish the glorious tasks entrusted to us by the times, so that the dry desert land will be rejuvenated and the mountains and rivers of the motherland will be more beautiful.