Recently, sandstorms ravaged northern China. What is the cause of sandstorm?

On March 15, the Central Meteorological Observatory upgraded the sandstorm warning to a yellow warning. There are obvious sandstorms in Xinjiang, Inner Mongolia, Gansu, Ningxia, Shaanxi, Shanxi, Hebei, Beijing, Tianjin, Heilongjiang, Jilin, Liaoning and other provinces 12, and sandstorms occur in some areas.

Recently, a large-scale sandstorm appeared in northern China for the first time, and yellow warning signals were issued in various places. Residents should pay attention to carrying dust-proof articles such as masks and scarves to avoid dust damage to eyes and respiratory tract. Sandstorm weather mainly occurs in winter and spring. This is because there is little precipitation in winter and spring in arid areas, the surface is unusually dry and loose, and the wind erosion resistance is very weak. When there is a strong wind blowing, a lot of dust will be involved in the air, forming sandstorm weather. Sandstorm is one of the main disastrous weather affecting northern China.

Sandstorm not only affects the environment and our daily life, but also does great harm to the human body. First, there are a lot of particles in sandstorm, which can be deposited in various organs of human body and cause diseases. Second, dust storms mixed with a large number of allergens such as pollen can cause allergic symptoms. Third, sandstorms are also mixed with a large number of bacteria and viruses, which are easy to invade the human body. Fourth, sandstorms will affect the radiation intensity of ultraviolet rays. Fifth, it has a negative impact on people's psychology.

A large part of the causes of sandstorms are over-exploitation of natural resources, over-cutting of forests and over-reclamation of land caused by population expansion. Therefore, in order to reduce the occurrence of sandstorms, we should also actively take preventive measures: First, strengthen environmental protection. Second, restore vegetation, strengthen biological protection system and prevent sandstorms. Three, according to the local conditions in different regions, formulate disaster prevention, disaster prevention and relief planning, actively promote various disaster reduction technologies, and build a model project, gradually from point to area, to further improve the regional comprehensive defense system. Fourth, control population growth, reduce the pressure of human factors on land and protect the environment. Fifth, strengthen the popular science propaganda on the relationship between the occurrence and harm of sandstorms and human activities, so that people can realize that once the living environment is destroyed, it will be difficult to recover, which will not only aggravate natural disasters such as sandstorms, but also form a vicious circle, and people should consciously protect their living environment.