*3.2. Spatial Interpretation of Land Use and Environmental Health in Changzhou*

3.2.1. Bivariate Spatial Association of Urban Expansion and High-Polluting Industries

The area of construction land in 1995 and 2015 was interpreted based on remotesensing images (Figure 5a,b) to examine urban expansion in Changzhou. Construction land in 2014 totaled 1075.77 km2, a significant increase compared with that in 1995 (618.63 km2). There were a total of 2802 high-polluting enterprises located in the coverage of the construction land in 2015. The number of enterprises located in the coverage of the construction land in 1995 was 1150, and the number of enterprises located in the coverage of the increased construction land was 1404. Errors in image interpretation suggested that some enterprises were not located in the coverage of construction land. In general, the results indicated that high-polluting enterprises significantly increased along with urban expansion during the period from 1995 to 2015 (Figure 5c,d).

**Figure 5.** Spatial evolution of construction land and high-polluting industries from 1995 to 2014: (**a**,**b**) is remote-sensing image in 1995 and 2014 respectively; (**c**,**d**) is POI of high-polluting enterprise in 1995 and 2014 respectively; (**e**,**f**) is Mora's *I* scatter plot and LISA cluster map respectiavely.

We calculated the number of newly increased enterprises in each 1 km × 1 km grid using point density analysis with ArcGIS software. Further, we examined the bivariate spatial associations between the area of newly increased construction land and the number of newly increased enterprises in each 1 km × 1 km grid. The bivariate global Moran's *I* was approximately 0.74, indicating that newly increased enterprises had a strong positive spatial association with newly increased construction land (Figure 5e). Figure 5f shows the bivariate local spatial clusters of newly increased enterprises and newly increased construction land. Clusters of High-High were mainly distributed in the suburban areas of Changzhou, including Wujin, Tianning, Zhonglou, and Xinbei. An exurb area in Xinbei and the northeast area of Jintan were also found with clusters of High-High, indicating that there were significantly high increases in both construction land and high-polluting enterprises. In contrast, rural areas far away from urban areas were found with significantly low increases in both construction land and high-polluting enterprises (clusters of Low-Low).
