Estimativa da evapotranspiração real diária através de análises micrometeorológicas e de sensoriamento remoto.

Abstract

The main objective of this study was to determine the daily actual evapotranspiration (ETr) of the banana crop and tamarisk vegetation utilizing micrometeorological data and remote sensing algorithms. The Bowen ratio and eddy covariance methods, and the Surface Energy Balance Algorithm for Land (SEBAL) and Simplified Surface Energy Balance Index (SSEBI) algorithms were used to obtain the ETr of the banana crop, located in the Frutacor farm (Quixeré, CE/Brazil) and of the tamarisk vegetation, located in the preserved area of the Cibola (Blythe, CA/USA). The behavior of the atmospheric parameters and its correlations with the reference evapotranspiration (ET0), for the both study areas were analyzed. The daily behavior of the evaporative fraction of the banana crop has been also analysed. The results evidence that both study areas had strong advection of the wind and dry air and the air temperature presented higher values during the day and lower values at night. In the Area I, the wind speed was the most influential component in obtaining the ET0, however, for the Area II, the solar radiation was the component most influential. In general, the estimated values by the SEBAL and S-SEBI algorithms present results close to the measured values in the flux towers. The RMSE between the measured values and the estimated values by SEBAL was 0.4 mmday-1, and for the measured values and the estimated values by S-SEBI was 0.5 mmday-1, resulting in a percentual mean error of 9.5% between the measurements and the SEBAL and 10.6% between the measurements and the S-SEBI, evidencing the applicability of both the algorithms in obtain the daily actual evapotranspiration.