Métodos de estimativa da evapotranspiração de referência (ET0) no município de Santa Teresa, ES

Abstract

Due to constant discussion about rationalization of water resources, the search for ways and good practices in water use have been increasingly widespread, especially in agriculture. Among the means of preserving water resources is irrigation management, so it is very important to estimate the reference evapotranspiration (ET0). In this context, the present work was developed for the municipality of Santa Teresa, located in Central Espírito-Santo mesoregion with the objective of evaluating and comparing different ET0 estimation methods with Penman-Monteith FAO56 method considered as calibration standard, in the absence of lysimetric data. The methods used were those of Hargreaves-Samani, Solar Radiation, Makkink, Jesen-Haise, Linacre and Penman Simplified. The coefficient of determination (R2), Willmott concordance index (D), mean absolute error (MAE), maximum error (EMAX), method efficiency (EF) and performance index (c) were used for assessing the observed indicators. Among the evaluated methods, the ones with the best results were Makkink and Penman Simplified (R2 = 0.96 and 0.96 D = 0.99 and 0.97, MAE = 0.23 and 0.44, EMAX = 1.36 and 1.07, EF = .95 and 0.87 and c = 0.97 and 0.95) respectively, followed by Hargreaves-Samani methods (R2 = 0.86, D = 0.91, MAE = 0.60, EMAX = 2.16, EF = 0.69 and c = 0.85). The results obtained with the methods of Linacre, Solar Radiation and Jensen-Haise were lower and their use is not recommended for the region of Santa Teresa, ES.