Role of surface hydrothermal elements in grassland degradation over the Tibetan Plateau

Under the influence of global warming and frequent human activities, a series of deterioration phenomena including the decreased productivity, decreased biodiversity, and ecological function degradation have taken place in the grassland ecosystem on the Tibetan Plateau. Compared with the traditional monitoring method, remote sensing technology has the advantages of wide range, rapid and continuous monitoring. Therefore, it is widely used to monitor grassland vegetation at the regional scale. Previous studies on impact factors of grassland vegetation on the Tibetan Plateau mainly focused on the climatic hydrothermal elements(i.e., temperature and precipitation). However, compared with the temperature and precipitation, the surface temperature and soil moisture have more direct effects on the physical and biochemical processes of vegetation growth. Based on remote sensing technology, MODIS and AVHRR data were collected on the Tibetan Plateau, and fractional vegetation cover was selected as the remote sensing in