What causes the haze

A few days ago Chai Jing self-funded million shot public service documentary "Under the Dome" placed online for people to watch for free, causing an uproar, Chai Jing declared war on the haze this time triggered an unprecedented public concern about the haze, what are the main causes of the formation of the haze? How is the haze formed? The main reasons for the formation of haze include the following factors.

Exhaust emissions

Exhaust emissions are the main and most direct factor leading to the appearance of hazy weather. Exhaust emissions include exhaust emissions from various automobiles, dirt work trucks, private cars, etc., as well as industrial emissions such as thermal power generation, including emissions from residents using coal and natural gas, and also emissions from farmers burning straw, straw and other crop residues.

Surface vegetation destruction

We all know that surface vegetation has an important role in nourishing water and preventing soil erosion. The trend of desertification in China is obvious due to the influence of climate and human factors, and the desertification of the surface leads to dusty soil, which is also an important factor in the emergence of haze.

Meteorological changes

The main component in the main in the haze is aerosol, and the suspension of aerosol in the air is influenced by meteorological conditions. For example, in the southern part of the rainfall in recent years less and less precipitation, air dust more and more serious, thus aggravating the haze; and North China in recent years the winter wind is weak, "scraping away" the haze, so last year Beijing-Tianjin-Tang area has become the hardest hit by the haze in China.

Dust from construction roads

In order to revitalize the declining economy, infrastructure construction is being carried out all over the country, especially the refurbishment of subways, railroads and highways, and many cities are showing a patchwork of potholes, as if they were urban patches; coupled with the real estate bubble and urban expansion, construction dust has also become an important factor leading to serious haze.

How the haze is formed

The appearance of haze actually refers to PM2.5 pollution, haze haze, mainly divided into "haze" and "fog". When PM2.5 reaches a certain concentration in the air, the visibility of the air is less than 10 km, which is "haze". PM2.5 particles mainly contain seven main components, some of which will absorb moisture when the relative humidity is high, and will be activated when the air conditions reach a certain level, turning into condensation nuclei of clouds and fog; PM2.5 will rapidly absorb water after becoming condensation nuclei, forming small droplets in the air and forming clouds. What you see in the air is "clouds", when the clouds and the ground receive together, it is called "fog".