You can't hang clothes tomorrow. What does the old man mean by wind dragon?

When the old man said wind dragon, he meant sandstorm.

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.

Sandstorm weather mainly occurs in winter and spring. This is because there is little precipitation in winter and spring in semi-arid and arid areas, the surface is extremely dry and loose, and the wind erosion resistance is very weak. When the wind blows, a lot of dust will be entrained in the air, forming sandstorm weather.

environmental factor

With the efforts of experts from the Institute of Environment and Engineering in Cold and Arid Regions, Chinese Academy of Sciences, the wind tunnel simulation experiment of sandstorm was successfully completed to explore the starting and transport mechanism of sandstorm materials.

Experts found through experiments that soil wind erosion is the primary link in the occurrence and development of sandstorms. Wind is the most direct driving force of soil, among which the nature of airflow, the magnitude of wind speed and the related conditions of wind action in soil wind erosion are the most important factors. In addition, soil water content is also one of the important reasons that affect soil wind erosion.

human factor

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 sandstorm is based on the special atmospheric circulation in East Asia, which is closely related to the winter monsoon. Its occurrence is mainly related to the cold front transit driven by Siberian-Mongolian high in winter, which belongs to cold front sandstorm.