Our country is one of the countries with serious desertification, what are the reasons for this? How

China is one of the countries with the largest and most serious desertification area in the world. The area of desertified land in the country is 10,000 square kilometers, accounting for the total land area. It is mainly distributed in Northwest China and North China, involving 18 provinces, autonomous regions and municipalities directly under the central government. �

Desertification has had a serious impact on China's industrial and agricultural production and people's livelihood. According to expert estimates, China's annual economic losses caused by desertification are as high as 54 billion yuan, and in some areas where desertification is serious, the problem of food and clothing for the masses has not yet been completely solved. At present, the general trend of desertification in the country is:

Desertification in some areas has been effectively controlled, and remarkable results have been achieved, but on the whole it is still expanding and deteriorating, and the desertified land in the country is still expanding at a rate of 2,460 square kilometers per year. The situation facing the fight against desertification is still very serious. �

China has always attached great importance to the prevention and control of desertification, and since the founding of the People's Republic of China, various measures have been taken to control large areas of desertified land. Since the launch of the desertification prevention and control project in 1991, the treatment and development area of 10,000 hectares has been completed, and a relatively complete ecological system has been initially formed in some sandy areas (such as many areas of the Horqin Sandy Land and the Mu Wu Sandy Land), and the ecological and social benefits have been developed in a coordinated manner. �

However, due to the weak awareness of combating desertification, driven by profit and population pressure, there is a situation of destruction while controlling, which leads to the continuous expansion of desertified land. At present, the desertification situation in China has been very severe, and the area of desertified land has accounted for the total land area of the country, while in arid, semi-arid and sub-humid arid areas, the proportion of desertified land has been close to 80%. In particular, the degradation of grassland and cultivated land directly related to the people's livelihood has been quite serious, the degradation rate of grassland has reached more than 40%, and at the same time, natural forests and artificial forests have also been seriously threatened, and there has been large-scale degradation and even decline, and the lower reaches of the Tarim River are 180 kilometers long"Green corridors"The river is on the verge of extinction due to a drastic decrease in the volume of water; The Alxa Oasis has shrunk by 10,000 hectares, the Juyanhai Sea has nearly dried up, and the Minqin Oasis is also declining rapidly, so that if some people continue like this, the Minqin Oasis will cease to exist in the next century.

According to the national census, since the 70s of the 20th century, China's desertified land has expanded at an average annual rate of 460 square kilometers. �

Indiscriminate felling Severely punish those who cut down trees.

Northwest and Northeast regions.

According to the materials published by the Office of Desertification Prevention and Control of the State Forestry Administration in 1998, China is one of the countries with serious desertification in the world. According to the results of the national desert, Gobi and desertification land census and desertification survey, China's desertified land area is 10,000 square kilometers, accounting for nearly 400 million people affected by desertification. According to research by the China-US-Canada International Cooperation Project, China's direct economic losses due to desertification are about 54.1 billion yuan.

The desertification of the land has created a material source for the sand to be raised by the wind. Therefore, sandstorms in northern China (strong sandstorms are commonly known as "black winds". Because of the sandstorm, you often can't see the five fingers) occurs more and more frequently, and the intensity is large, and the scope is wide.

On May 5, 1993, severe sandstorms struck Xinjiang, Gansu and Ningxia, killing or missing 116 people, injuring 264 people, losing tens of thousands of livestock, affecting 10,000 hectares of crops, and causing direct economic losses of 100 million yuan. From April 15 to 21, 1998, a severe sandstorm swept through arid, semi-arid and sub-humid areas of China from west to east, passing through Xinjiang, Gansu, Ningxia, Shaanxi, Inner Mongolia, Hebei and western Shanxi. On April 16, the dust floating in the air settled in Beijing, Tianjin and the north of the lower reaches of the Yangtze River, forming a large area of floating dust.

Among them, Beijing, Jinan and other places meet the rain cloud system due to floating dust, so the "mud rain" falls from the sky. In Yinchuan, Ningxia, due to the continuous falling of sand, the plane was grounded, and people even found it difficult to breathe.

Minqin in Gansu Province is one of the areas prone to sandstorms in China. Between 1998 and 2006, there were an average of 11 sandstorms per year.

2016 New Curriculum Standard) Geographical factors of frequent sandstorms in Minqin, Gansu Province: the desert around Minqin is widely distributed (rich sand sources and little vegetation), the temperature rises rapidly in spring, the precipitation is less, the surface is dry, and it is easy to form sand; Cyclones and cold air are frequently active (just on the path of the cold wave moving south), and windy weather is frequent. Affected by the topography (narrow tube effect), the wind speed on the ground increases.

(1) Causes of desertification.

From the perspective of natural factors, the soil is loose, coupled with the large number and concentration of windy days, the climate is arid, and the precipitation is low;

The main manifestations of human factors are excessive firewood, overgrazing, over-reclamation, improper use of water resources, and lack of attention to environmental protection in industrial and mining transportation.

2) Desertification control.

rational use of water resources; the use of biological and engineering measures to build a protection system; regulating the relationship between agriculture, forestry and animal husbandry; Adopt comprehensive measures to solve the energy problem in agricultural and pastoral areas in multiple ways; Population control (or: adjust the land use structure, return farmland to forest and grassland; expand the area of forest and grassland, and intensively manage the lowland between the hills with good water and soil conditions; It is also possible to create field protection forests and shelterbelts).

The phenomenon of land desertification in China is very serious according to the figures provided by the state every year. Of China's 9.6 million square kilometers, 2.7 million square kilometers are desertified, and the northwest of China is the most serious area of desertification.

Along with the phenomenon of desertification, there will be various unfavorable ecological problems, aiming at desertification in the northwest region.

Measure. 1. Rational use of water resources.

2. Use biological and engineering measures to build a shelterbelt system.

3. Regulate the relationship between agriculture, forestry and pastoral land.

Fourth, take comprehensive measures to solve the energy problem in agriculture, forestry and pastoral areas in multiple ways.

Fifth, control population growth.

Core: Harmony between man and nature.

Measures: 1. Save water, you can wash the dishes with water, wash the dishes, and then flush the toilet ......2. Controlling population growth.

Third, water resources and forest resources should not be destroyed indiscriminately.

Fourth, we should plant more trees, so that the environment will become better.

Fifth, there should be harmony between people, animals and nature, and this friendship should not be destroyed.

1. Natural causes. The climate is arid, with little precipitation, many windy days and strong winds; The ground is sandy sediment, and the wind and sand damage are serious; There is little surface runoff, and the river is underdeveloped; Vegetation is scarce, and there is a lack of vegetation protection on the ground; The climate is abnormal.

2. Human causes. excessive wide sedan car grazing; Over the Imperial Command; over-reclamation; irrational use of water resources; No attention is paid to environmental protection in the construction of industrial and mining transportation.

1. Plant management, desert plant management refers to the sowing of psammophytes in desert areas to prevent desert expansion and improve desert land. Psammophytes have the characteristics of less water transpiration, developed mechanical organization and transport organization, etc., which can resist the attack of strong winds, and transport water and spine orange material to the organs in urgent need as soon as possible, and often maintain a high osmotic pressure in their cells, and have a strong ability to continuously absorb water, so that the plant is not easy to lose water and can adapt to the environment of drought and little rain.

2. Water resources utilization, water resources utilization is the most important in the process of desert governance, the main water sources in the desert are groundwater, river water and precipitation, but the precipitation in the desert area is unstable, generally changes with the change of climate, the precipitation in wet years is more, and the precipitation in dry and warm years is less, the groundwater in the desert is more stable, its sand layer is thick, has a certain thermal insulation, so that the water can be preserved underground, but this stability is relative, subject to the restriction of precipitation. The solution of water resources is mainly considered from the aspects of water withdrawal, water transportation and water-saving irrigation.

3. Restoration and reconstruction, the fundamental cause of the formation and expansion of desertification, is caused by the man-made destruction of the desert ecosystem, is the result of the inherent stability and balance imbalance within the system caused by the intensive development and utilization of water resources, biological resources and land resources in the system.

<>1. Desertification includes desertification.

2. Causes of desertification.

1) (the most important natural factors) drought, evaporation is greater than precipitation, deep inland, far from the sea, ocean water vapor is difficult to reach. Surrounded by high mountains, it is blocked by the Qinghai-Tibet Plateau.

2) How windy.

3) Close to the source of the winter wind (Siberia), the terrain is undulating, and there is no high-altitude core mountain to block it, so that the strong wind drives straight in.

4) Vegetation is scarce and the vegetation coverage rate is low.

5) The soil is loose and desert (this is the basis of desertification).

6) Cold currents flow through temperature and humidity reduction.

7) Reclamation of over-delayed bridges: adjust the land use structure.

8) Overgrazing: The number of livestock should be adapted to the carrying capacity of the pasture, and the policy of returning grazing to grassland should be improved.

9) Excessive wood mining: take comprehensive measures to solve the energy problems in agricultural and pastoral areas (such as solar energy, etc.) in multiple ways.

10) Irrational use of water resources: rational use of water resources.

11) The construction protection of traffic lines and other projects is not: strengthen management and protection of code loss.