The Spatial and Temporal Variation of NDVI and Its Relationships to Climatic Factors in Northern Tibet over the Period of 2000-2010 -Take Shantsa for Example
To reveal the effects of climate change on vegetation ecosystems, we used atime series (20002010) data set of Normalized Difference Vegetation Index (NDVI) together with historical climate data to analyze interannual variations of NDVI and explore the relationships between NDVI and climatic factors in Shantsa in this paper. The results showsthat NDVI decreased bya magnitude of - 0. 0013 and a ratio of - 0. 55%/a during the growing season(p =0. 069) over recent decade. The NDVI increasing area accounts for a total area of 32.78%,while the NDVI decreasing area accounts for a total area of 67. 22% in Shantsa. The NDVI increasing areais alpine vegetation, which is distributed inhigh altitude area. The NDVI decreasing areais alpine meadow and alpine steppe, the latter is more sensitive than the former. Increased temperature whichleads todrought climate may be the main reason for NDVI decreasing.