NDVI Variation and Its Responses to Climate Change on the Northern Loess Plateau of China from 1998 to 2012

Table 1

Gradation standard for land desertification.

Desertification grade	Vegetation coverage	NDVI
Extremely severe	<0.1	<0.19
Severe	0.1–0.3	0.19–0.34
Moderate	0.3–0.5	0.34–0.51
Light	0.5–0.7	0.51–0.78
Slight	>0.7	0.78–0.83