Estudo da estrutura da evapotranspiração na região Nordeste do Brasil utilizando estatística multivariada.

Abstract

This study presents a criterion to identify and to evaluate the importance o f the variables involved in the process of evopolrnnspiration for the use of the technique of multivaried statistics, Principal Components Analysis, This technique is applied with the intention to identify the relative importance of the different variables involved in the evapotranspiragao of the northeast region of Brazil. The historical series had been supplied by the INMET (National Institute of Meteorology), CPTEC (Climatic Center of Forecast of Time and Studies), INPE (National Institute of Space Research) and DCA (Department of Atmospheric Sciences) of the Federal University of Campina Grande. The technique of the Principal Components Analysis demonstrated that a model with two main components is adjusted to represent the process of the evapotranspiragao in the studied area. The results had disclosed that the investigated variables climatologicas with bigger representation in the process of the evapotranspiragao had been: precipitation (P), relative humidity of air (UR), evaporation (E), and speed of the wind (V); while that the minimum temperature of air (TMN) presented minor influence for the Northeast region of Brazil.