The Central Meteorological Observatory continued to issue a blue warning of sandstorms. Why do sandstorms often occur in spring?

Due to the dry climate in spring, there is strong cold air invasion, which is the season with frequent sandstorms; The basic condition of sandstorm formation is sand, and the soil from sand source should be dry and loose; As a kind of high-intensity sandstorm disaster, sandstorm can't happen in all windy places, but only in those areas with dry climate and sparse vegetation. The forest coverage rate in northwest China is not high, and some excessive predatory exploitation and destruction have aggravated the sandstorm disaster in these areas. And in spring, when everything just wakes up, many plants have no leaves, and the water loss is accelerated, which leads to low defense, which leads to sandstorms.

In Gansu, Shaanxi and other places, there is dusty weather, full of yellow sand, the city is looming, and the air is a pungent smell of dust and soil. This round of dust will affect most parts of northwest and north China. Sandstorm weather can be divided into four categories: floating dust, sand blowing, sandstorm and severe sandstorm, followed by weather phenomena with visibility less than 10km, 1km to 10km, 1km and 500m. Sandstorm will bring great winds, sand burial, soil wind erosion, air pollution and other hazards.

From late February to May in spring, Mongolian cyclones are prone to appear and develop rapidly, and there are many sand source belts nearby. Affected by factors such as rising seasonal temperature and melting snow, loose sand on the surface easily rises into the air with strong winds, leading to frequent sandstorms in spring. In windy and dusty weather, the visibility is reduced, the line of sight becomes worse and the line of sight is short, which is easy to cause traffic accidents. When driving, pay attention to keep the distance between vehicles, stay away from the buffer green belt, identify the wind direction, drive slowly, prevent vehicles from running off, and avoid special vehicles such as overload, ultra-high, ultra-wide, trailers, tankers and dangerous chemicals. Pay attention to pedestrians and bicycles changing direction temporarily to avoid sandstorms. When driving at night, you should use the anti-glare low beam instead of the high beam, and stop at the parking place. Dust weather, the increase of inhalable particles in the atmosphere, can stimulate the eyes, nose, throat, skin, affect the respiratory system, aggravate the condition of patients with cardiovascular diseases, and increase the spread probability of infectious diseases.

Dust can enter bronchi and bronchioles and finally deposit in alveoli, causing acute and chronic respiratory diseases such as bronchitis, pneumonia and emphysema. Therefore, it is not advisable to open the window for ventilation, wear masks, glasses, hats and scarves when going out, wear bright clothes to reduce traffic accidents, and try to avoid riding bicycles. The elderly, infants, pregnant women, the weak and patients with respiratory diseases and heart diseases should reduce physical consumption and outdoor activities.

Therefore, it is necessary to plant a variety of green plants that do not wither all the year round to prevent surface water loss, reduce the occurrence of bad weather and protect the environment.