Annual Actual Evapotranspiration Estimation via GIS Models of Three Empirical Methods Employing Remotely Sensed Data for the Peloponnese, Greece, and Comparison with Annual MODIS ET and Pan Evaporation Measurements

Actual evapotranspiration (ETa) has been insufficiently investigated in Greece. This study aimed to estimate annual ETa by empirical methods (Turc, modified Turc, and Coutagne) for the Peloponnese, Greece, a Mediterranean testbed, between 2016–2019, four of warmest years since preindustrial era, compare them MODIS ET. Furthermore, measurements pan evaporation (Epan) were performed two Class A stations Peloponnese with different reliefs conditions. The statistical formulae (RMSD, MB, NMB) developed as models ArcMap. outcomes Turc method resembled ET ranges all years, followed those Coutagne. estimates almost identical Therefore, can be used an alternative (and vice versa) 2016–2019. Moreover, Epan at Patras University station (semiurban, low elevation) exhibited upward trend resembling trends over whereas Ladonas (higher elevation, lakeside) required investigation on monthly time scale. Additionally, gradual decrease pan-water icing December (from 20 d 2016 0 2019) could imply undergoing snowpack storage retention across mountains Peloponnese.