ABSTRACT
The monitoring and evaluation of land degradation is the core component of desertification studies. As a technology of air-to-ground observation, remote sensing technology has become an important research approach of the geosphere, atmosphere, biosphere and cryosphere, because of its broad detection range, fast data collection, large quantities of information acquired in a short period and at a low cost. The main soil monitoring indicators of land degradation include soil type, soil moisture, surface particle size of the soil and extent of soil erosion amount. Promoted by the International Geosphere-Biosphere Program and the International Human Dimensions Program on Global Environmental Change, land use and cover change research quickly became a focus area in the study of global environmental change in the 1990s. The assumption of the unsupervised classification of remote sensing is that the same object in the same condition has the same spectral characteristic.
