MODELOS GEOESTATÍSTICOS NA AVALIAÇÃO E ESTIMATIVA TEMPORAL DA EVAPOTRANSPIRAÇÃO DE REFERÊNCIA

The Reference Evapotranspiration (ET0) is an important hydrometeorological variable in various applications: in integrated planning of water resources management and land use for agricultural and forestry projects. ET0 information is not readily available in much of the Brazilian territory, requiring the use of alternative methods and techniques for its quantification. This study aimed to estimate ET0 using FAO Penman-Monteith, which in turn allowed us to visualize its spatial behavior, conduct a statistical analysis, and evaluate the temporal variation process of ET0 through geostatistical methods of kriging and variograms in three locations in the State of Pará. The modeling showed that ET0 has strong temporal dependence. The highest frequencies were for values between 3.5 mm and 4.00 mm. Similar demand for ET0 was observed among the locations, as well as its seasonality, due to the behavior of the input variables that influence its estimation. The kriging method highlighted periods of higher and/or lower ET0 values. The adjusted variograms had R2 > 0.86 and the sum of squares of residuals (SQR) close to zero.