Desempenho de métodos de estimativa de evapotranspiração de referência na Região Sul de Goiás

Abstract

The present study aimed to evaluate the performance of the reference evapotranspiration estimation methods (ETo) in the South of Goiás. Meteorological data were collected from five locations in the South of Goiás, in which were Catalão, Rio verde, Morrinhos, Jatai and Itumbiara, being a question for selected local young people who will have at least ten years of data. Five equations were analyzed, Turc, Hargreaves and Samani, Priestley and Taylor, Camargo and Makkink taking as a reference the standard Penman-Monteith-FAO method. All data collected, totaling thirty-three years (1980 to 2013), were provided in spreadsheets in Microsoft Excel®, where comparisons were made taking into account the annual period and the seasonality of the dry (May to October) and rainy periods ( November to April). Comparisons of daily performance of ETo methods were performed through correlation analysis, through linear regression and statistical indexes. The best method of estimating ETo on an annual scale and in the dry and rainy season was the Turkish optimum performance for all locations. The worst methods were those of Hargreaves and Samani and Camargo, who obtained equally poor performances in all consumption parameters.