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Where did the sandstorm in China start?
Sandstorm refers to the weather phenomenon that strong winds blow up dust on the ground, making the air very turbid and the horizontal visibility less than 1km. Sandstorm is a weather phenomenon in wind erosion and desertification, and its formation is influenced by both natural factors and human activities. Natural factors include strong wind, decreased precipitation and its sand source. Human activity factor refers to the increase of sandstorm frequency after vegetation destruction in the process of economic development.

In China, there are two sandstorm-prone areas.

The first frequent area is in the northwest, mainly concentrated in three areas, namely, the surrounding area of Tarim Basin, Turpan-Hami Basin passing through Hexi Corridor, Ningxia Plain to northern Shaanxi, Alashan Plateau, Hetao Plain and Ordos Plateau in Inner Mongolia.

The second frequent area is in North China, Chifeng and Zhangjiakou, which directly affects the safety of the capital Beijing.

The sandstorm in China is getting more and more serious, which is mainly caused by unreasonable land development and unreasonable farming. With the increase of population and inadequate management, a large amount of land in northwest and north China has been reclaimed, grasslands have been overgrazed, and natural vegetation has been destroyed artificially, resulting in a large number of bare and loose land, which provides a large number of dust sources for the occurrence of sandstorms. Once a strong wind occurs, it will affect society and endanger people's health.

dust storm/devil

How are sandstorms formed?

The formation of sandstorms requires these three conditions:

One is the dust on the ground. It is the material basis for the formation of sandstorms.

The second is the strong wind. This is the dynamic basis for the formation of sandstorms and the dynamic guarantee for the long-distance transportation of sandstorms.

Third, the air state is unstable. This is an important local thermal condition. Sandstorms often occur in the afternoon and evening, which shows the importance of local thermal conditions.

Man-made factors: the occurrence of sandstorm is not only the product of specific natural environmental conditions, but also has a corresponding relationship with human activities. Man-made overgrazing, deforestation, industrial and mining traffic construction, especially man-made overgrazing, destroyed the ground vegetation, disturbed the ground structure, formed a large area of sandy land, and directly accelerated the formation and development of sandstorms.

Meteorological factors: The formation of sandstorms is based on the special atmospheric circulation in East Asia, which is closely related to winter winds. Its occurrence is mainly related to the cold front crossing driven by Siberian-Mongolian high in winter, which belongs to cold front sandstorm.