In meteorology, according to the magnitude of wind speed and its influence on horizontal visibility

Meteorology, according to the magnitude of wind speed and its influence on horizontal visibility, sandstorm weather is divided into five grades: floating dust, sand blowing, sandstorm, strong sandstorm and extra-strong sandstorm.

Sandstorm weather is one of the main disastrous weather affecting northern China in spring. It refers to a weather phenomenon that the wind drags dust and sand on the ground into the air, making the air turbid. 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 1 km.

Sandstorms in northern China mainly appear in spring, and the dust sources mainly include Gobi Desert in southern Mongolia, Eastern Kazakhstan Desert, Badain Jaran Desert, Tengger Desert, Wulanbuhe Desert, Taklimakan Desert, Kumtag Desert and Gurbantunggut Desert.

In case of dusty weather, the public should be prepared for wind and sand prevention and close doors and windows in time; Pay attention to wearing masks and other dust-proof products to avoid dust damage to the respiratory tract.

Spatial distribution:

Sandstorms in China mainly occur in the northern region, among which southern Xinjiang basin, southwestern Qinghai, western Tibet, central and western Inner Mongolia and central and northern Gansu are the most frequent areas, with annual sandstorm days exceeding 10, and southern Xinjiang basin and parts of western Inner Mongolia exceeding 20 days.

There are still 3~ 10 days in Junggar basin, Hexi corridor and parts of northern Inner Mongolia. Less than 3 days in the southeastern part of Northwest China, south-central and eastern parts of North China, Huanghuai, the central and western parts of Northeast China and parts of Xinjiang, Qinghai, Sifang and Hubei provinces (regions).