Temporal and Spatial Variation of NDVI in Tibetan Plateau from 1982 to 2008

The long term documents of AVHRR-PathFinder (19822000) and SPOT-Vegetation NDVI (20012008) were chosen to analyze the change trend of normalized difference vegetation index (NDVI) in Tibetan Plateau. The results show that (1) the maximum of NDVI in this region is no more than 0.4, which illustrates the low vegetation coverage in Tibetan Plateau; the value of NDVI presents the slowly rising trend. Moreover, the seasonal change of NDVI is increased slowly in autumn. (2) The slope of NDVI is from 0.024/27 a to-0.025/27 a; and it presents decreasing trend from southeast to the northwest in Tibetan Plateau; the features of spatial variations in spring, summer and autumn are increasing in most region of Tibetan Plateau. While the changes of region in spring, summer and autumn are wider than that in winter. The change of vegetation coverage in most of the Tibetan Plateau is not obvious except the southeast area in Tibet and the minority areas in the northwest of Yunnan province.