COMPARING REMOTELY-SENSED EVAPOTRANSPIRATION ESTIMATES FROM THE S-SEBI AND METRIC MODELS OVER THE BRAZILIAN PAMPA

The Mapping Evapotranspiration at High Resolution with Internalized Calibration (METRIC) and the Simplified Surface Energy Balance Index (S-SEBI) are well-known as appropriate surface energy balance models in providing evapotranspiration (ET) estimates spatially distributed. Therefore, the objective of this study was to compare these two ET models over the natural vegetation of the Brazilian Pampa biome, based on Landsat data between 2014-2019. To evaluate the models accuracy, eddy covariance (EC) measurements from a flux tower were used. The METRIC and S-SEBI models showed a good accuracy against the in situ data with correlation coefficient, RMSE, and MAE of 0.72, 1.15 mm/day, and 0.96 mm/day, respectively, for METRIC and 0.84, 1.06 mm/day, and 0.79 mm/day, respectively for S-SEBI, thus showing a superior performance. Both models accurately captured daily ET dynamics seasonally, especially during the growing season, making them suitable for early detection of water stress on the Brazilian Pampa vegetation.