China has a centuries-long history of putting fireworks on Chinese New Year’s Eve. However, as air pollution attracts more attention, fireworks became a target of criticism because they produce much smoke, dust, and hazardous gases like sulfur dioxide. What impact does fireworks have on air quality? What kinds of policies do cities have concerning fireworks, and are these policies effective?
The project was awarded in short list at Information Is Beautiful Awards.
1) Banning fireworks has become a common practice for the 50 most populated municipalities in China. During 2017 Chinese New Year, 22 out of the 50 municipalities banned fireworks; and in 2018, this policy is extended to 11 more municipalities. Most of them with the ban only bans fireworks in downtown areas, allowing fireworks in suburban and rural areas. Only three cities carries out a complete ban within their administrative boundary.
To rule out most confounding factors and solely see the impact of fireworks on air quality, we applied a scholarly index by researchers from Institute of Atmospheric Physics, Chinese Academy of Sciences. This index divides the hourly concentration of PM2.5 by the hourly concentration of carbon monoxide. The smaller the ratio, the less pollution caused by fireworks. We got the air quality data from National Urban Air quality release platform, and calculated the data using the method mentioning above.
2) The visulization was plotted using Processing.
What was the hardest part of this project?
1) It is almost common sense that firework ban is for the benefit of air quality, even though there were repeated discussions of protecting fireworks as holiday cultures every year. We tried to address the issue by using data.
2) The visualization is in the form of firework, demonstrating the data clearly, while stressing the topic.
3) We tailored the visualization on different platforms. For the mobile version, the data is demonstrated in a side-by-side format. And municipalities are arranged by policy types, since that’s the key variable for the storytelling. For the PC interactive version and poster version, we maximize the capacity of larger screen. We located each pair of data vertically, and the difference between 2017 and 2018 can be compaired. We arranged municipalities horizontally, and the readers and see all the 50 municipalities’ data at one glimpse. They were first catgorized by policy types, and the users can regroup the data by the air quality rankings of 2017 and 2018. The difference between two years can also be highlighted by clicking on a compare button.
What can others learn from this project?
Comparisons between air conditions during 2017 and 2018 Chinese New Year are made for all 50 municipalities, It’s rather clear that this ban has a positive influence on air quality, because when compared with air conditons during 2017 Chinese New Year, the municipalities that started this ban in 2018 experienced better air quality during 2018 Chinese New Year.
In addition to a general comparison between 2017 and 2018, the choice of polar bar chart helps readers to identify the most popular times to put fireworks if fireworks are at least partially allowed in a municipality. Usually, people start to put fireworks after the midnight of New Year’s Eve.
As metioned above, only three municipalities banned fireworks completely; observing the spatial differences within a muncipality that has a partial ban also says something about the environmental consequences of fireworks. Beijing is used as an example here. After midnight of 2018 New Year’s Eve, suburban areas turned around the table to surpassed downtown areas in terms of PM2.5 concentration.
Visually, polar chart charts are intended to mimic the shape of firework display. It also corresponds to the fact that with more fireworks, the air is more polluted. We used yellow polar bar chart showing the 2017 data and the pink one showing the 2018 data.