4. CONCLUSIONS 
The main objective of this study was to retrieve surface soil 
moisture from MODIS TVDI and AMSR-E soil moisture data. 
The TVDI was estimated by empirical analysis of NDVI-LST 
space. The TVDI results verified with monthly rainfall data 
showed close relationship between TVDI and rainfall. The 
results archived by regression analysis between the TVDI results 
and AMSR-E soil moisture data indicated strongly negative 
correlation between both datasets (R*=-0.82) and RMSE of 39.8. 
The areas of low soil moisture were mainly distributed in western 
part of the study area. The temporal evolution of TVDI showed 
expanded areas of low soil moisture in April that typically 
returned to wet conditions by the end of September. This study 
has shown a merit of using MODIS data to retrieve 
high-resolution surface soil moisture compared to AMSR-E soil 
moisture. Such a method for retrieving surface soil moisture with 
a better spatial resolution than the available ASMR-E soil 
moisture data in Taiwan could be transferable to other places in 
the world. 
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