How is the intensity of dust divided? What can be classified as a sandstorm?

What are floating dust, sandstorm and strong sandstorm?

Sandstorm weather can be divided into four categories: floating dust, sand blowing, sandstorm and strong sandstorm.

Sand blowing and sandstorm are caused by dust and sand grains on the surface of a specific area brought by the strong activity of large airflow. Their * * * features are obviously reduced visibility and cloudy weather. It mostly happens when cold air passes through the border or is affected by thunderstorms and squall lines, and it is easy to happen in spring in the north. The difference is that the horizontal visibility of sandstorm weather is between 1 km and1km. The horizontal visibility of sandstorm weather is less than 1 km. When the horizontal visibility is less than 500m, it is defined as a strong sandstorm.

Floating dust is formed by fine particles such as dust and sand floating in the air after sandstorm or sand blowing in remote or local areas, commonly known as "falling yellow sand". When it appears, distant objects are khaki, the sun is yellowish or yellowish, and the horizontal visibility is less than 10 km, which generally appears before and after cold air passes. We usually call floating dust "inhalable particles". Because its light particles can float in the atmosphere for a long time, the floating range is tens of kilometers, and they can accumulate in the atmosphere, gradually increasing the degree of pollution.

Dust weather is actually a normal weather phenomenon in spring, and its quantity is related to a specific weather system and underlying surface. After global warming, the temperature rises and the precipitation decreases, which is beneficial to the development of desertification, so in this sense, it is beneficial to the increase of dust. According to the data released by the State Forestry and Grassland Administration in June last year, since the "Thirteenth Five-Year Plan", China's desertification control has achieved remarkable results. However, desertification is a global problem and requires the joint efforts of all countries in the world. Only by improving the overall ecological environment can it be effectively reduced.

Dust weather will have a great impact on the environment. Floating dust has greatly increased the incidence of eye diseases and respiratory diseases, especially for the elderly and children who have low adaptability to environmental changes and are prone to illness. Many tiny inhalable particles enter and stay in human lungs, which is harmful to health. The yellow sand in the sky also makes people feel depressed and depressed. Most of the flying dust falls on the leaves, which affects the respiration and photosynthesis of plants. Dust greatly reduces the visibility and brings inconvenience to people's travel, so the traffic accidents caused by it are also on the rise.