Correlation Analysis of Evapotranspiration, Emissivity Contrast and Water Deficit Indices: A Case Study in Four Eddy Covariance Sites in Italy with Different Environmental Habitats

Evapotranspiration (ET) represents one of the essential processes controlling exchange energy by terrestrial vegetation, providing a strong connection between and water fluxes. Different methodologies have been developed in order to measure it at different spatial scales, ranging from individual plants an entire watershed. In last few years, several methods approaches based on remotely sensed data over ecosystems for estimation ET. present work, we outline correlation ET measured four eddy covariance (EC) sites Italy (situated either forest or grassland ecosystems) (1) emissivity contrast index (ECI) thermal infrared spectral channels MODIS ASTER satellite sensors (CAMEL data-set); (2) deficit (WDI), defined as difference surface dew point temperature modeled ECMWF (European Centre Medium-Range Weather Forecasts) data. The analysis covers time-series 1 7 years depending site. results showed that both ECI WDI correlate calculated through EC. relationship WDI-ET, coefficient determination ranges, study area, 0.5 0.9, whereas ranges 0.7 when was correlated ECI. slope sign latter is influenced vegetation habitat, snow cover (particularly winter months) environmental heterogeneity area (calculated this concept variation hypothesis using Rao’s Q index).