How changes in extreme precipitation impacts hydraulic structure design storms

With a global concern about climate nonstationary and predictions of more extreme weather events, considering new rainfall distribution patterns is necessary using the most current and complete data available at any location. In this study, extreme rainfall frequency is analyzed using daily precipitation data in Kansas located in the central United States and Tuscany in the central Italy. From Kansas, 39 stations with data from 1920-2009 are selected, while for from Tuscany Region, 472 stations with daily time series of at least 15 years in the period 1916-2017 are used in the analysis. Initial analysis showed an increase in extreme precipitation events in Kansas with extreme event values tending to increase in magnitude from the northwest to southeast part of the state. Comparing results of the first period (1920-1949) to the last of three study periods (1980–2009) showed that approximately 90% of the state had an increase in short-term rainfall event magnitudes. Long-term event magnitudes were predicted to be higher in 66% of the state. Tuscany analysis is being conducted. Generally, results show a shift in rainfall distribution patterns in Kansas and Tuscany spatially and temporally. This shift changes the design criteria for hydraulic infrastructures, both in runoff control and storage structures.