SEASONAL PERFORMANCE OF THE REFERENCE EVAPOTRANSPIRATION IN AQUIDAUANA, MATO GROSSO DO SUL STATE, BRAZIL

Abstract

The aim of this study was to determine the reference evapotranspiration by assessing the accuracy of empirical methods Benevides-Lopez, Camargo, FAO-24 Radiation, Hamon, Hargreaves-Samani, Klarrufa, Jesen-Haise, Makkink, Prietley-Taylor, and Turc, comparing with the Penman-Monteith FAO-56 in different seasons in Aquidauana, Mato Grosso do Sul State, Brazil. This work was done with the collected daily weather data obtained between the period from 01 January 2008 to 31 December 2011 in the network of stations of the Instituto Nacional de Meteorologia (National Institute of Meteorology), located in Aquidauna-MS. Were evaluated daily values of reference evapotranspiration (ETo) in mm day-1 for the summer period, autumn, winter and spring, using empirical methods and Penman-Monteith, parameterized by FAO in which he served as a model for comparison. Were determined and considered in theevaluation of methods the average ETo, the coefficient of determination (r2), correlation (r) and standard error of estimate (SEE). To evaluate the accuracy of the methods evaluated were determined the level of agreement (d), and the performance index (c). Given the number of data, it is concluded that the methods Priestley-Taylor and Solar Radiation cater satisfactorily to estimate reference evapotranspiration in Aquidauna-MS for all seasons.