ESTUDO COMPARATIVO DE DIFERENTES METODOLOGIAS PARA DETERMINAÇÃO DA EVAPOTRANSPIRAÇAO DE REFERÊNCIA EM EUNÁPOLIS - BA

Abstract

The aim of this work was to evaluate some empirical equations performance used to estimate the evapotranspiration of reference in relation to the standard method Penman-Monteith FAO - 56 for the climatic conditions of the city of Eunápolis - BA. Climatic variables were used as referrals to the years of 2006 to 2007 obtained through the automatic platform collection of data from Hydrical Resources Superintendency of Bahia / National Institute for Space Research, where it was obtained the average for two years. In order to compare the values of ET0 estimated by empirical equations with the standard method Penman-Monteith (FAO 56), were considered the parameters of the regression equation (a and b), the coefficient of determination (r²), coefficient correlation c, estimate of the standard err (EEP), index of agreement (d), index of confidence or performance c, in the scales of one, three, five and seven days. The results obtained from this study reveal that the Hargreaves-Samani method overestimated the ET0 in 23% characterizing it as the less method to estimate it. The methods of Radiation and Blaney-Criddle satisfactorily met the estimate of ET0 for the climatic condition on the studied region.