Evapotranspiration estimates using NOAA AVHRR imagery in the Pampa region of Argentina

We used multiple regression analysis to relate evapotranspiration( ET), com puted from a water balance technique, to both thermal infrared and normaliz ed difference vegetation index data obtained from the Advanced Very High Re solution Radiometer (AVHRR) sensor on board on the National Oceanic and Atm ospheric Administration (NOAA) satellite. This approach, based on only remo tely sensed data, provided a reliable estimate of ET over the Pampas, the m ain agricultural region of Argentina. The relationship between spectral dat a and ET was more sensitive to the dates than to the sites used to generate the models.