Abstract

The performance of the METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration) model was evaluated to estimate instantaneous sensible (H i) and latent heat fluxes (LE i) over an experimental plot of a drip-irrigated Merlot vineyard (Vitis vinifera L.) of 4.25 ha (35°25' LS; 71°32' LW; 125 m.a.s.l). This study was carried out using data obtained between the years 2006 and 2009. Ground data of sensible and latent heat fluxes were measured by an Eddy Covariance (EC) system. METRIC estimations of H i and LE i considered fifteen days where Landsat scenes were available. The pixel by pixel METRIC estimations were averaged using the pixels inside the experimental plot. Measured and estimated instantaneous values of H i and LE i were analyzed using the coefficient of determination (R 2) and the mean absolute error (MAE). Results indicate that METRIC overestimated H i by 10% (MAE = 39 W m -2) while LE i was overestimated by 14% (MAE = 33 W m -2). Results of this study indicated that the self-calibration of METRIC in H i allowed obtain acceptable values of LE i .