Analysis and Prediction of the Coupling Coordination Relationship between Tourism and Air Environment: Yangtze River Economic Zone in China as Example

Figure 4

Geographical distributions of the CCD. (a) 2009; (b) 2010; (c) 2011; (d) 2012; (e) 2013; (f) 2014; (g) 2015; (h) 2016; (i) 2017; (j) 2018.

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

(i)

(j)