Wednesday, May 28, 2014

Bubble pie map of daily AQI over main Chinese cities during 1st quarter 2014

China bubble pie map of daily AQI showing pollution over main cities during Q1- 2014

In addition to our previous post, the above chart is showing that in average the days where air quality was good (AQI < 50) have been very limited over main chinese cities during the first quarter. 

This ranking covers the 190 largest cities in China, about 416 Mil people, accounting for about 63% of the urban population.

 Averaged over the urban population and during Q1-2014 period of 90 days, the daily AQI repartition had been the following: 
  • 8 days /90 days or only 9% of total days had  AQI<50
  • 37 days /90 days or 41% had 50<AQI <100
  • 45 days or 50% had AQI>100
The area where the most polluted cities were located is shown in Figure 1 below. In this vast swath of land straddling the Northern and the Middle zones, urban citizens have seen virtually no days with AQI <50 during Q1 2014, apart Chongqing and Beijing.

Figure 1: China bubble pie of daily AQI zooming the Beijing- Wuhan- Chengdu- Xi'an semicircular area where are located the 30 most polluted cities

The  Southern coastal area presented in Figure 2 hereunder had shown over Q1-2014 relatively very few days where AQI was >100, but the good days with AQI<50 were generally very limited and the air was mostly moderately polluted (50<AQI<100).

Figure 2: China bubble pie of daily AQI zooming the Southern Chongqing-Shanghai-Guangzhou triangle of relative moderate pollution

The Southernmost cities of Haikou and Sanya located in Hainan "beautiful island" , were the only main cities with a majority of good air quality days: Haikou and Sanya had respectively 52 and 61 good days (AQI<50) on the 90 days period.