Causes of haze weather

1. Poor pollutant diffusion conditions

The high-rise buildings in the city and the obstruction of ventilation corridors make the particles in the air accumulate in the urban area and cannot diffuse.

Rivers in cities lead to low ground temperatures and high high-altitude temperatures. The air flow in the vertical direction is restricted, forming an inversion layer of "hot at the top and cold at the bottom". The particles in the air are pressed at low altitudes, making it difficult to Diffusion upward.

2. The intensity of pollutant emissions is high

Pollution emissions mainly include industry, coal burning, motor vehicles, dust, etc. For example, as the demand for cars increases, exhaust emissions will inevitably increase, emissions from industrial production, dust on construction sites, waste incineration, etc.

3. Regional transmission impact

In a transmission channel, such as Beijing-Tianjin-Hebei and surrounding "2+26" cities, the average impact on each other is 20% -30%. When heavy pollution occurs, it will increase to 35% to 50%. In some cities, it may reach 60% to 70%. The impact on each other is obvious.