Air Pollution and the Public Perception Level and Self-Protection Demand in Three Cities of China: Fractional Grey Modelling Analysis

Figure 11

The relationship between Baidu index of environmental protection behavior and AQI. (a) Beijing. (b) Tianjin. (c) Shijiazhuang. (d) AQI of three cities.

(a)

(b)

(c)

(d)