Análise quantitativa entre métodos de estimativa da evapotranspiração horária integrada e diária no Brasil

Abstract

Evapotranspiration is the fusion of two natural processes of soil water loss, which are:evaporation and transpiration. The evaporation consists of a change of state of thewater that is contained in the soil, passing from the liquid to the gaseous state. In turn,the transpiration of plants occurs when the vegetable performs the nutrition process.Quantitative information from such processes provides a more accurate water slidethat helps solve problems involving water management in agriculture. The Penman-Monteith FAO56 equation makes it possible to calculate the estimate of the referenceevapotranspiration measure in one day from the hourly data summed over 24 hoursand from daily data.The main objective of this work is to promote a trial regarding the statistical evalua-tion of estimates of evapotranspiration reference evapotranspiration in one day fromthe hourly data summed over 24 hours and from daily data, comparing them throughlinear regression, interval confidence interval, statistical bias, Wilmott concordance in-dex, decorrelation index, confidence index, and performance rating according to theconfidence index. The data used were from all over Brazil, from January 1 to Decem-ber 31 of 2017. The specific objective is to evaluate the estimates of the two methodsunder the quantitative aspect. The results showed that in Brazil the estimated dailyevapotranspiration estimate is overestimated by approximately 8.32% when comparedto the integrated hourly reference evapotranspiration. The South had the highestR2with 0.927, while the Midwest had the lowest with 0.857. The R ranged between 0.963and 0.926, being South and Center-West, respectively. The d ranged from 0.979 to0.960, to the South and the Midwest, respectively. The c also presented higher value inthe South and the lowest in the Center-Oente. For all regions, the performance ratingaccording to the confidence index was ”Great”.