Modelos SEBAL e METRIC para estimativa da evapotranspiração da cultura da banana irrigada.

Abstract

This work aimed to estimate the daily real evapotranspiration (ETr) through the application of Surface Energy Balance Algorithm for Land (SEBAL) and the Mapping evapotranspiration at high resolution with internalized calibration (METRIC) algorithms from remote sensing products, in an irrigated area with dwarf banana cultivation in the municipality of Barbalha-CE and compare it with the evapotranspiration estimated through the Penman-Monteith method, on different dates in 2016. For this, the Landsat- satellite images were used. 8 OLI/TIRS, and additional surface data from the automatic meteorological station located in the municipality of Barbalha-CE. The processes of stacking the bands, cutting the stacked images, and processing the images were carried out by ERDAS imagine software, in which the mathematical operations to determine the evapotranspirations were carried out. The real daily evapotranspiration values of the banana tree estimated by the SEBAL and METRIC algorithms followed those found in the bibliography. In the cultivated area, the values of daily evapotranspiration by SEBAL ranged between 4.40 and 6.5 mm day-1. As for the METRIC, the variation occurred between 5.0 to 6.8 mm day-1. Through the absolute and relative errors used to compare the actual evapotranspiration estimated by SEBAL with the Penman-Monteith method, the differences are insignificant between the evapotranspirations for May 22, August 10 and October 29, 2016 (6.0; 7.4 and 8.4%, respectively). Between the METRIC and Penman-Monteith algorithm, these evapotranspiration differences were in the order of 6.0, 7.4 and 4.4% for May 22, August 10 and October 29, 2016. Thus, both the algorithms exhibited errors basically equal to and less than 9%. What is considered a satisfactory and acceptable level of accuracy. Thus, not showing a better performance among them to estimate the daily evapotranspiration values.