12. Evaluating Actual Evapotranspiration by Means of Multi-Platform Remote Sensing Data: A Case Study in Sicily

During the last two decades, the scientific community developed detailed mathematical models for simulating land surface energy fluxes and crop evapotranspiration rates by means of an energy balance approach. These models can be applied in large areas and with a spatial distributed approach using surface brightness temperature and some ancillary data retrieved from satellite/airborne remote sensed imagery. In this paper a district scale application, in combination with multispectral satellite and airborne data has been carried out to test the potential of two different energy balance models to estimate evapotranspiration fluxes from a set of typical Mediterranean crops (wine, olive, citrus). The impact of different spatial resolutions on model-derived fluxes has been investigated in order to understand the roles and the main conceptual differences between the two models which use a “single-layer” (SEBAL) and a “two-layer” (TSEB) schematization, respectively. The critical spatial resolution of remote sensed data has been also investigated.