Spatial-temporal Changes of NDVI and Their Relations with Principal Climatic Factors in Yarlung Tsangpo River Basin's Stations

As an index of denoting basin's vegetation cover,NDVI is influenced by many climatic factors such as precipitation and average air temperature.The spatial-temporal change of NDVI is analyzed in Yarlung Tsangpo River basin.Meanwhile,the point data of NDVI data on basin's stations is extracted based on stations' latitude and longitude.Then,relation of NDVI and precipitation or average air temperature is analyzed on the basin's stations.The conclusion is that NDVI and principal climatic factors(precipitation and average air temperature) on the basin's stations are intensive with season,and are in consistency with time,and are higher in correlation.The linear correlation coefficient of NDVI and precipitation is 0.77,and that of NDVI and average air temperature is about 0.72 on the basin's stations. And logarithmic correlation coefficient of NDVI and precipitation is 0.7,and that of NDVI and average air temperature is 0.68 on the basin's stations.