Applicability of TVDI in Monitoring Drought in Longdong Area of Gansu, China
Clear principle and concise physical meanings make Temperature Vegetation Dryness Index (TVDI) be a wildly used method in drought monitoring.It was not temporal comparable that building feature space by using single time remote sensing data in most former studies.In this paper, NDVI-LST, EVI-LST and SAVI-LST feature space is building by history MODIS data and the applicability is discussed.The results showed that: (1) In over all, TVDI method can be used to monitoring the Relative Soil Moisture (RSM) status in Longdong area.The correlation between TVDI calculated by EVI-LST space and RSM is highest.(2) Land Surface Temperature (LST) corrected by DEM improved TVDI method.In one hand, goodness of fitting of the dry and wet edge is improved.On the other hand, the correlation between TVDI and RSM is improved in a manner.(3) Building feature space though history remote sensing data is a reasonable and feasible method.Temporal and spatial comparable are enhanced by this method.TVDI indicated the history RSM spatial distribution every single year well and the variance of RSM in different year well too.
NETL
NSTL
万方数据
维普
