Preliminary analysis about the effects on the SPI values computed from different best-fit probability models in two Italian Regions

Droughts are one of the most challenging issues in water resource management in urban areas due to their major socio-economic impacts. The identification and evaluation of droughts are commonly based on the Standardized Precipitation Index (SPI), which is estimated through easily accessible information (i.e., monthly rainfall). In this work, we show a preliminary analysis on the role played by the nature of the probability distribution in the calculation of the one-month SPI. Long-term rainfall time series from two Italian regions are investigated.