Research on Ecoenvironmental Quality Evaluation System Based on Big Data Analysis

Table 3

Principal component analysis results of indexes in 1991 and 2000.

Index	1991				2000
	PC1	PC2	PC3	PC4	PC1	PC2	PC3	PC4
Wet	0.284	0.070	0.864	0.410	0.184	−0.088	0.762	0.615
NDVI	0.479	0.613	−0.426	0.461	0.509	0.369	−0.536	0.564
NDSI	−0.420	−0.404	−0.203	0.787	−0.713	−0.306	−0.308	0.551
LST	−0.716	0.675	0.176	0.009	−0.446	0.873	0.195	0.017
Characteristic value	0.011	0.002	0.001	0.000	0.013	0.003	0.001	0.000
Eigenvalue contribution rate	77.43	16.66	5.23	0.68	73.65	19.16	6.09	1.10