EVALUATION OF METHODS TO ESTIMATE EVAPOTRANSPIRATION AT THREE LOCATIONS OF NORTHERN MINAS GERAIS

• Autor(a) principal: Alencar, Leonidas Pena
• Data de Publicação: 2011
• Outros Autores: Sediyama, Gilberto Chohaku, Wanderley, Henderson S., Almeida, Thomé Simpliciano, Delgado, Rafael Coll
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Engenharia na Agricultura
• Texto Completo: https://periodicos.ufv.br/reveng/article/view/233
• topic: Blaney Cridlle; Hargreaves-Samani; Penman–Monteith; Priestley-Taylor; modelos empíricos; radiação

The objective of this study was to compare the methods of Blaney Criddle, Hargreaves-Samani, Priestley-Taylor and Radiation with the standard method Penman-Monteith (FAO 56), to estimate evapotranspirtaion under the climatic conditions of Montes Claros, Espinosa and Salinas, located in the northern Minas Gerais. Analysis was done using 10 years (1996 to 2005) daily data regarding maximum and minimum temperatures, wind speed, sunshine and relative humidity. To compare the ETo estimated by using empirical equations with the standard method of Penman-Monteith (FAO 56) the following parameters were used: ‘a’ and ‘b’ of the regression equation, coefficient of determination (R²), correlation coefficient (r), the mean absolute error, root mean square error, the agreement index and the confidence or performance index. The methods were evaluated for two seasons, during low evaporative demand in the months of April to September, and high demand during October to March. In both seasons, the methods of Blaney and Criddle Priestley Taylor proved to be more precise. The method of Hargreaves-Samani was unsatisfactory under the weather conditions studied.