Wavelet analysis of rainfall data of the aguapeí­ -peixe hydrographic basins (state of São Paulo)

Abstract

With the use of the Wavelet analysis, this study aimed to detect the dominant oscillations and phenomena that influence the occurrence of extreme rainfall events in the basins of the Aguapeí­ River and the Peixe River in order to generate information useful to water management. Rainfall data from 18 stations in the State of São Paulo were used, in the period from 1958 to 2013, obtained through the National Water Agency (ANA). The temporal scales that influence the rainfall and the occurrence of extreme events at each rainfall station of the basins were identified, in which the approximately 22-year scale related to the Pacific Decadal Oscillation (PDO) was the dominant in all rainfall stations. The study pointed out that the association of different temporal scales contributes to the increase in the rainfall index, on the other hand, the lack of them relates to years of low rainfall index.