A Remote-Sensing Ecological Index Approach for Restoration Assessment of Rare-Earth Elements Mining

Table 2

Area and proportion by grades of ecoenvironmental quality from 2013 to 2020.

Quality level	2013		2016		2019
	Area (km^2)	Proportion (%)	Area (km^2)	Proportion (%)	Area (km^2)	Proportion (%)
Very poor (0–0.2)	24.18	10.76	20.32	9.04	11.34868	5.05
Poor (0.2–0.4)	24.16	10.75	22.70	10.10	19.5512	8.70
Medium (0.4–0.6)	49.60	22.07	37.60	16.73	33.30445	14.82
Good (0.6–0.8)	85.82	38.19	97.35	43.32	91.48612	40.71
Very good (0.8–1.0)	40.97	18.23	46.74	20.80	69.01348	30.71
Mean	0.584199		0.613026		0.666642
Total area, km^2	224.7264