Abstract
This paper aims to evaluate the application of the Standardized Precipitation Index (SPI) for the monthly (SPI-1), quarterly (SPI-3) and annual (SPI-12) scales for Paraná slope of the Itararé watershed (PSIW). Were used the rainfall data from fourteen pluviometric stations obtained from the Paraná Water Institute and the Paraná Agronomic Institute for the period between 1976 to 2012 in the spatiotemporal evaluation of SPI developed by McKee et al. (1993)McKEE, T.B.; DOESKEN, N.J.; KLEIST, J. The relationship of drought frequency and duration to times scale. In: VIII Conference on Applied Climatology. Boston. American Meteorological Society, p. 179-184, 1993.. The interannual variability of SPI-12 and the relative frequency of SPI-3 and SPI-1 categories were evaluated. It was verified that 71.1% of the years were classified as close to normal and however, from July to September there was a significant increase in droughts in the PSIW according to SPI-3 and SPI-1. In the autumn and winter the highest frequency was observed in the categories of drought, whereas in the spring normality prevailed and in the summer the humid categories were more expressive. The use of the SPI index for different scales showed that although the SPI-12 scale prevailed in the normality category, the SPI-3 and SPI-1 scales showed more accurately the quarters and months of greater susceptibility to droughts in the PSIW.
Keywords:
drought; water resources; climate risks
