Rain and evapotranspiration using the Penman-Monteih model for the periods 1963-1982. 1983-2001 and 2002-2019 for the amparo de São Francisco – Sergipe, Brazil

Evaluate the performance of the empirical method of estimating evapotranspiration, with the standard Penman-Monteih method, suggested by FAO-56, for Amparo de São Francisco – Sergipe in the periods 1963-1982; 1983-2001 and 2002-2019 generating their respective graphs and information for government decision makers. The Penman-Monteih method makes it possible to estimate (ETo(PM)) in mm/month and, after computing it, it is multiplied by the total number of days in each month of the year, thus obtaining the Penman-Monteith model estimated in mm/month. The standard Penman-Monteih method can help with irrigation planning and management, especially for small irrigators who do not have access to meteorological data. A better adaptation of the Penman-Monteith and Thornthwaite model was observed in the estimation of ETo, where its results showed adaptation for the location studied. It is advisable to evaluate other models so that they can provide more appropriate results. It is stated that the Penman-Monteith and Thornthwaite models are the best alternatives for the use of evapotranspiration in Amparo de São Francisco - Sergipe.