Evapotranspiration Estimation with the S-SEBI Method from Landsat 8 Data against Lysimeter Measurements at the Barrax Site, Spain

Evapotranspiration (ET) is a variable of the climatic system and hydrological cycle that plays an important role in biosphere–atmosphere–hydrosphere interactions. In this paper, remote sensing-based ET estimates with simplified surface energy balance index (S-SEBI) model using Landsat 8 data were compared situ lysimeter measurements for different land covers (Grass, Wheat, Barley, Vineyard) at Barrax site, Spain, period 2014–2018. Daily produced superior performance than hourly all covers, average difference 12% 15% daily estimates, respectively. Grass Vineyard showed best performance, RMSE 0.10 mm/h 0.09 1.11 mm/day 0.63 mm/day, Thus, S-SEBI able to retrieve from 0.86 mm/day. Some uncertainties also analyzed, we concluded overpass missions represents neither maximum nor ET, which contributes increase errors estimated ET. However, can be used operationally agriculture sites good accuracy sufficient variation between pixels, thus being suitable option adopted into operational sensing programs irrigation scheduling or other purposes.