Evapotranspiration in the Brazilian municipalities surrounding the Itaipu Binacional reservoir: characterization process and estimation methods

Seeking to contribute with the management of water resources in Itaipu Binacional reservoir region, this research aimed characterize dynamics evapotranspiration and evaluate performance different mathematical methods, which determine reference (ETo) from air temperature values. Fifteen municipalities were analyzed. After obtaining data series, ETo was estimated using six methods: Camargo (C), Hargreaves-Samani (HG-S), Jensen-Haise (JH), Penman-Monteith missing (PMm), Thornthwaite-Camargo (TW-C) (PM) – latter method. The methods analyzed by several statistical indexes. Daily values ranged 2 10 mm d-1, an annual mean 5.78 d-1. We also observed that it is determined predominantly radioactive parameters, annually represent 76% process, while aerodynamic parameters 24%. Among estimation HG-S PMm most suitable for estimating.