TVDI Based Soil Moisture Retrieval from Remotely Sensed Data for the Central Tibet

Ts-NDVI(Normalized Difference Vegetation Index) feature space was constructed by combining 8－day composite MODIS temperature product(MODl1A2) and 16－day composite MODIS NDVI product(MODl3A2) ，It is used temperature vegetation drought index which based on the feature space as drought monitoring indicators．The results showed that the serious drought from 2000 to 2011 in summer is mainly distributed in the south and around the river valley，the drought in the northern is not so serious as other regions，while when the most of the values of the temperature vegetation drought index are in the range from 0.2 to 0.4，we can regard them as normal or light drought area．After comparing the temperature vegetation dryness index results with the traditional meteorological elements analysis method ones，the inversion result is consistent with the actual situation，what’s more，this paper draw a conclusion that they two have a better linear positive correlation．In a word，using the temperature vegetation drought index as the widespread drought monitoring model in plateau area has a certain reference and scientificity．