Map of Air Quality in China
Here are the Scales, From top to bottom:
No Basis
Excellent Air Quality
Okay Air quality
Slightly Polluted
Lightly-Moderately Polluted
Moderately Polluted
Moderately-Heavily Polluted
Heavilily Polluted
Year
Image Type
Category
Level
Geographic Area
Source
http://s5.sinaimg.cn/mw690/53b45416hd32e1cbb7e44&690