Air pollution in Beijing, 2013-2017


Understanding Beijing’s climate, problems and progress

Mapping time against Air Quality

Here we would display how the different components of pollutants would distribute across different time ranges and cycles. We would notice the patterns of particles and poisonous molecules in the span of a day, or four seasons.

AQI Levels' annual variance

This is an overview of AQI levels for an average day in each month of the years involved in the dataset.

 

In a seasonal sense, it is noticeable that winters and nights are the most suffering in all the years; but in some particular years we have April hikes, possibly because of another long-standing but currently partially solved problem: sandstoms from the Gobi Deserts in the grand north of China and Mongolia.

Air quality over each hour

This is a general overlook of the whole year of all pollutant articles.

 

In a annual sense, we can notice that the smog come in waves. PM10, the most noticeable element of a smog, reaches a high level in a very short time, and then goes away instantly, never trying to last for a particularly long term. Other pollutants are relatively stable/invariant, but generally Ozone levels rise and fall simply because of temperature and season.

Annual average changes in air quality

On annual average, urban air quality levels are nearly constantly higher than rural ones (which is intuitive since the the major source of pollutants are urban ones including factories, power plants and cars).

 

In 2016 we have seen a significant drop in air pollution in most sources, while the seemingly rise in 2017 is due to the fact that data only covers the first two winter months, in which the main source of pollution comes from burning coal for thermal supply towards households.

Generally, there has been some progress made in reducing levels of pollutants, which could include moving out factories, promoting electric cars, etc.

Air quality over each hour

On the whole, PM10, PM 2.5 and NO2 levels rise at night and drops by day; O3 levels rise significantly during the day and drops through the night. We can notice its highest level around late afternoon and early evening, since the primary source of ozone is the discomposition of nitrous oxides and VOCs (Volatile organic compounds) under sunlight and ultraviolet light. This also explains the lowest point of NO2 and SO2 concentrations being late afternoon.

 

IThe rise of PM10 and PM2.5 in the early night could be due to the night rush hour congestion leading to higher car emissions, and a higher usage of electricity because of turning on the lights; since there are not many factories in the city proper, (especially the ones that use very significant amounts of electricity, iron and steel production being one example), during the day the concentration of PMs ar bit lower. PMs generate from burning all kinds of heavy fossil fuel (excluding natural gas) for energy and transportation.

Air quality over each month

It is still clearly seen that winter months suffer more from days of worse air quality, with all pollutants except ozone being more concentrated in winter than in summer on the whole.

Considering Beijing’s climate, in summer it is obviously hotter much hotter and rich in sunlight. Ozone generates from discomposition of oxides in light, and winter hours are normally short.

PM particles, however, typically generate from burning coal, and there are also the burning of corn or rice stalks in order to restore fertility to the farmlands. In the winter days lesser precipitation and wind contribute to even harder removal of smog particles.