Table 2.

Significance test of AQI and NVDI in different regions of mainland China during the lockdown period was achieved by paired sample t test

Region	Standard error of the mean	Correlation	Sig. (bilateral)
North China	5.722	0.017	0.001
Northeast China	8.398	0.066	0.003
East China	6.630	0.968	0.002
Central China	5.613	0.938	0.001
South China	3.598	0.893	0.001
Southwest China	3.689	0.948	0.000
Northwest China	3.110	0.102	0.000