SPATIO-TEMPORAL ANALYSIS OF THE REFERENCE EVAPOTRANSPIRATION UNDER DIFFERENTS REGIMES OF THE PRECIPITATION PERNAMBUCO

Faced with the need for conservation of water resources it is necessary to better irrigation management. The objective of this research was to analyse the water requirement in Pernambuco State, Brazil, represented by the evapotranspiration reference (ET0), in diferents regimes annuals of precipitation: rainfall, regular and dry. The ET0 values were estimated through the Thornthwaite e Mather (1955) method starting from data originated by the registration of 45 climatological stations of the SUDENE (Superintendence of Northeast Development). In general, the results showed that the ET0 were variable on the three Mesoregion, reaching medium values from 915 to 1.549 mm year(-1). The Pernambuco State presents an annual water deficit in approximately 70% of its total area. The months that presented the greatest and smallest water requirements in the State were January and July, respectively. The knowledge of spacial and temporal distribuition of ETo on Mesoregions of Pernambuco bring benefits to producers who can make water management more suited to local crops.