Characterizing Drought Risk in a Sicilian River Basin

The chapter summarizes the results of the application of proposed methodologies for drought characterization and risk assessment in water supply systems to the Italian case study, namely the Simeto River basin in Sicily. In particular, after a general description of the case study, the results of the drought identification, carried out by means of several drought indices and methods such as the Standardized Precipitation Index (SPI), the Palmer Hydrological Drought Index (PHDI) and the Run Method, are presented. The application of a methodology developed for the assessment of return periods of drought events identified on historical series of annual precipitation is also reported. Then, the methodology for risk assessment presented in chapter 6 is applied to the Salso-Simeto water supply system, which is a part of the larger system of the Simeto River. In particular, a Montecarlo simulation of the system is carried out in order to assess both unconditional (long term) and conditional (short term) drought risk. Also, drought impact assessment on rainfed agriculture is presented. Finally, drought mitigation measures historically adopted within the Simeto River basin in order to reduce drought impacts in urban and agricultural sectors are described.