Should Desert and Desertification Regions Be Confused? New Insights Based on Vegetation Quality and Its Inter-Decadal Variations

As the most unique ecosystem on the Earth’s surface, desert and desertification region cannot be confused. The current research on spatial distinction of desert and desertification region is still lacking. Based on NDVI (normalized difference vegetation index) data from 1998 to 2020, we aimed to distinguish the differences between desert and desertification region. Improvement and degradation of vegetation quality in China have coexisted in the past 20 years. Within the low value classification in 1998, the regions where vegetation quality remained High increase were mainly concentrated in Loess Plateau. Within the medium value classification in 1998, the High increase classifications were mainly distributed in the west of the Taihang Mountains, north of the Qinling–Daba Mountains, east of the Qinghai–Tibet Plateau, Yunnan–Guizhou Plateau, and the Northeast Plain. Within the high value classification in 1998, the High increase classification was distributed in the south of the Yangtze River. In 1998 and 2020, China had a total area of 2.50 million km2 of desert regions, accounting for 26% of China’s land area. After 20 years of large-scale ecological protection, desert regions have hardly undergone significant changes. Desertification regions decreased from 2.80 million km2 to 1.67 million km2, a decrease of 40.3%.