-
Anonymous users2024-02-12In addition to reducing visibility, sandstorms also have many hazards, it will erode the soil on the surface, affect the growth of plants, lead to reduced crop yields, and greatly reduce air quality, easy to get upper respiratory diseases, in short, it is a bad thing, so to eliminate sandstorms, afforestation is still very important.
-
Anonymous users2024-02-111. Sandstorms.
Causes: Nature: drought, high winds, rising air currents; Anthropogenic: Destruction of vegetation.
Distribution: Northwest China, North China (spring).
Hazards: Reduced atmospheric visibility, endangering health, transportation, lakes, reservoirs, agricultural production, villages, cities.
Measures: Biological measures: protection of existing vegetation and afforestation; Engineering measures: cross-basin water transfer, water diversion for irrigation; Management measures: returning farmland to forests and pastures.
2. Desertification.
Causes: Nature: arid climate, degraded vegetation, intensified physical weathering, strong winds; Anthropogenic: deforestation, over-reclamation, overgrazing.
Distribution: Northwest, North China, West Northeast China.
Harm: The ecological environment has deteriorated, and the area of cultivated land, forest land and grassland has decreased.
Measures: Biological measures: protection of existing vegetation and afforestation; Engineering measures: cross-basin water transfer, water diversion for irrigation; Management measures: return farmland to forests and grasslands.
3. Eutrophication of water bodies.
Causes: A large amount of waste liquid containing N and P is discharged into ponds, lakes and rivers.
Distribution: suburbs of towns, rivers, lakes and seas.
Hazards: Lack of oxygen in the water affects the survival of aquatic organisms.
Measures: Reduce the use of fertilizers and pesticides; the use of chemical fertilizers and pesticides with low retention; Industrial wastewater and domestic sewage are discharged into rivers, lakes and seas after treatment.
-
Anonymous users2024-02-10The reason for the formation of sandstorms is the low precipitation in dry areas in winter and spring. And the surface is dry and loose, and the wind erosion resistance is weak. Therefore, when a strong wind blows, a large amount of sand and dust will be swept into the air, forming a sandstorm.
The formation of a dust storm requires three necessary conditions: dust matter, high winds, and unstable air conditions. Sandstorm is a general term for sandstorms and dust storms, which are a sign of desertification.
Sandstorm: Sandstorm is a general term for sandstorms and dust storms, and is a sign of desertification. It refers to a disastrous weather phenomenon in which strong winds roll up a large amount of sand and dust from the ground, making the horizontal visibility less than 1 km, and having the characteristics of suddenness and short duration.
Among them, sandstorm refers to the sandstorm formed by strong winds blowing a large amount of sand into the near formation; A dust storm is a storm formed by high winds that sweep large amounts of dust and other fine particles into the air.
-
Anonymous users2024-02-09Shi Yulin, academician of the Chinese Academy of Engineering and head of the land desertification research group, pointed out that sandstorms are a natural phenomenon that cannot be eliminated. However, unreasonable human economic activities have contributed to or promoted the occurrence and development of sandstorms. He believes that the expansion of desertified land in northwest China is an important reason for the increase in the intensity of sandstorms in China in recent years, and the situation of ecological and environmental management cannot keep up with the destruction has not been fundamentally reversed.
Shi Yulin pointed out that in the long-term historical evolution, various problems have emerged in the ecological environment of the northwest region, such as drought and water shortage, drying up of rivers and lakes, soil erosion, and vegetation degradation. According to expert research, the main crisis of the ecological environment in Northwest China is comprehensively manifested in land desertification. Although there are other ecological and environmental crises, in general, land desertification is the main ecological and environmental crisis.
He pointed out that from the perspective of natural laws, sandstorms cannot be eliminated. Humans should and can only mitigate the harm of dust storms by eliminating the adverse factors caused by humans themselves.
Shi Yulin said that the results of the two national land desertification surveys in 1994 and 1999 showed that the northwest region, whether it was desertification or desertification, showed a trend of spreading, expanding, and aggravating.
Shi Yulin said that in the northwest region, the two main human reasons for the expansion of desertified land are the irrational use of water resources and the irrational use of land resources.
He believes that the correct relationship between human beings and the desert should be that people and the desert coexist in harmony, and that it is necessary to avoid "sand entering and people retreating", and not blindly "marching to the desert". In general, deserts should not and cannot be destroyed or "conquered".
Dust storm. Sand-Dust Storm) is a general term for sand storm and dust storm, which is a sign of desertification. It refers to a disastrous weather phenomenon in which strong winds roll up a large amount of sand and dust from the ground, making the horizontal visibility less than 1 km, and having the characteristics of suddenness and short duration. >>>More
1. Sandstorms are formed by the wind blowing up a large amount of sand and dust on the ground and rolling them into the air. >>>More
Sandstorms are the products of specific natural environmental conditions, and have a corresponding relationship with human activities, artificially overgrazing and deforestation of forest vegetation, industrial and mining transportation construction, especially man-made excessive reclamation to destroy ground vegetation and disturb the ground structure, will form a large area of desertified land. Dust storms will form. Sandstorm is due to the strong wind blowing up the sand and dust on the ground, so that the atmospheric visibility is sharply reduced disastrous weather, since the founding of the People's Republic of China shelter forest measures and planting trees and grass at the edge of the desert and other projects, to prevent and control the occurrence of sandstorms have played an important role, so China does not often have sandstorms.
Sand duststorm is a general term for both sandstorm and duststorm, which refers to a severe sandstorm weather phenomenon in which strong winds blow up a large amount of sand and dust on the ground and roll it into the air, making the air particularly turbid and the horizontal visibility is less than 100 meters. Sandstorms refer to sandstorms formed by strong winds blowing a large amount of sand into near-surface formations. A dust storm is a storm formed by high winds that sweep large amounts of dust and other fine particles into the air.
Under the condition of good vegetation growth, the underlying surface can trap more rainwater runoff (replenishing the ground through infiltration on sunny days), and the flood peak arrival time is later and the peak flow is smaller (compared with the latter case). If the vegetation growth is poor (such as Gobi and desert), the ability of the underlying surface to store rainwater runoff decreases, the runoff retention time is shortened, the peak flow increases, and the flood peak arrival time is advanced, which will increase the risk of flooding to a certain extent. Under the conditions of urbanization, the vegetation is destroyed in large quantities and replaced by impervious underlying surfaces, and the in-line drainage method is adopted, which greatly increases the risk of flooding by advancing the arrival time of flood peaks and increasing peak flows! >>>More