Hydrological information from temporal and spatial variation in surface temperature/vegetation index

As part of the INTEO project (Integration of Earth Observation data in agrohydrological models), the Ts-NDVI relationship has been analysed for 41 NOAA-AVHRR images from 1990 covering West Africa. A new dryness index based on the Ts-NDVI space is suggested, and the spatial and temporal variation of the index is analysed. The method is promising, and the potentials of including the information in a distributed hydrological model seem large. However, work still has to be done on setting up methods to define the coefficients for the index, and the index has to be calibrated to soil moisture