The Standard Precipitation Index (SPI) is used in state and national monitoring programs of the drought conditions in several Brazilian regions. Based on the hypothesis that the analysis of long term SPI time series might help on the adoption of policies of mitigation and facing climate anomalies, this work aims to analyze the variability of monthly SPI, in Campinas (SP) during the years from 1890 to 2007. From spectral analyses and non-parametric tests, a variability of three to four years scale was noted for this index. However, a remarkable influence of the El Niño/Southern Oscillation on the variability of monthly climate conditions in Campinas was not seen. Concerning the long term trends, while a strengthening trend of rainfall deficit was noted during August, no significant alterations was noted for the other months. Under the academic point of view, the probabilistic and standard treatment of deficit/excess of rainfall used in the SPI calculation makes it an interesting alternative index in investigating the conditioning/modulating climatic forcing of the climate of a given region.
temporal variability; SPI; drought
