Analysis of the Influence of the Elements Methodology on Evapotranspiration in Morada Nova, in Ceará

The reference evapotranspiration is an important agrometeorological parameter for planning and irrigation management and can be estimated by several methods. In the Brazilian Northeast, irregular and contingent water resources, studying evapotranspiration means optimizing irrigation management. This study aimed to analyze the influence of climate elements on the reference evapotranspiration calculated by the FAO-56 Penman-Monteith equation to the climatic elements of maximum and minimum temperature of the air, relative humidity, wind speed and insolation of a period of 53 Years, granted by INMET, of the city of Morada Nova in Ceara, whose climate according to the classification of Koppen is BSw'h '; Hot and semi-arid climate. The reference evapotranspiration was calculated according to the procedures suggested by FAO 56. The sensitivity analysis was based on the addition and decrease of one climatic element at a time in ± 5% up to the limit of ± 40% between -40% and -30% %, -20%, -15%, -10%, -5%, + 5%, + 10%, + 15%, + 20%, + 30% and + 40%, while maintaining the values of the other elements Constant. The results showed that the variation of the elements of the climate between dry and rainy season did not change the sensitivity of the Penmam-Monteith FAO 56 model to the evaluated climatic elements. The Penmam Motheith model, in the climatic conditions of Morada Nova, CE, is more sensitive to the elements of maximum temperature of the relative humidity of the air, followed by insolation, wind speed and minimum air temperature.