What conditions are needed for the formation of sandstorms? What is the real harm to the earth?

From the scope of influence, the sandstorm weather affected Xinjiang, Inner Mongolia, Gansu, Ningxia, Shaanxi, Shaanxi, Hebei, Beijing, Tianjin, Liaoning, Jilin, Heilongjiang and other 12 provinces (autonomous regions and municipalities directly under the Central Government). Affected by the north wind, sandstorms will not be ruled out, and will further develop to the south. Judging from the impact intensity, in addition to sandstorm weather, sandstorms have also appeared in western Inner Mongolia, Hexi, Gansu, northern Ningxia, northwestern Shaanxi, north-central Hebei, Beijing and other places. Dust weather is divided into five grades: floating dust, sand blowing, sandstorm, ginger yellow sand and special yellow sand. Among them, the grade of Jiang Huangsha is called "the weather phenomenon that strong winds blow away dust on the ground, the air is very turbid, and the horizontal field of vision is less than 500 meters".

The formation of sandstorm should meet three conditions: strong wind, sandstorm and unstable air. Zhang said that the causes of sandstorms are mainly affected by two factors. First, affected by the cushion conditions, it is said that the thermal conditions are very good. In the early stage, the temperature in Mongolia and northwest China was obviously higher, the precipitation was less, and various indicators were gradually thawed, so sandstorm particles were easy to cause sand blowing. Influenced by the strong Mongolian cyclone, the dynamic conditions are sufficient. Strong winds of 9- 1 1 were blown successively in northern Xinjiang, central and western Gansu, Inner Mongolia and even northern North China, which provided very good dynamic conditions for the occurrence of this sandstorm.

Sandstorm weather mainly occurs in winter and spring, because there is little precipitation in dry areas in winter and spring, the surface is unusually dry and loose, and the wind resistance is weak. If there is a strong wind, there will be a lot of sandstorms in the air, forming sandstorm weather. Then, why are sandstorms so frequent in 16 countries? Let's briefly analyze the influence of natural conditions. Geographical conditions are the prerequisite for the formation of sandstorm weather. 16 China, except Cheng Han, most of the other regimes are located on the north side of the 3354 Qinling Line of Huaihe River, that is, the north of China. Most of northern China belongs to temperate continental climate. The main characteristics of this climate are cold in winter and spring, drought and little rain, and the annual evaporation of water is much greater than the annual precipitation. This creates a premise for the formation of sandstorm weather.

Yingjun University has more than 80 main wheels and more than 900 foundations. Jiaping Zhao two years ago: Gefei badminton, Su Yang 15th, shipbuilding. In the eighth year of Zhao Jianwu, tiger lion Tai Tai sent prison sacrifices and became a palace. Since ancient times, there have been more than 40 books, and Osaka Changan Luoyang has left the palace with more than 400,000 authors. It is this uncontrolled civil construction in Datong that has caused a large number of forests to be cut down, plants to be destroyed, and the land to remain bare, which has lost its restraining effect on strong winds and accelerated the emergence of dusty weather to a certain extent.