Assessing the reliability of regional depth-duration-frequency equations for gaged and ungaged sites

Design storms are usually estimated by analyzing observed rainfall extremes. When there are no measured data for the location of interest, the design storm may be estimated using regional depth-duration-frequency equations (RDDFEs). The annual series of precipitation maxima obtained for a dense network of rain gages located in northern central Italy are analyzed in order to (1) investigate the statistical properties of the rainfall extremes and compare them with the characteristics reported in published studies, (2) develop RDDFEs for the estimation of design storms for storm durations from 1 to 24 hours and recurrence intervals up to 100 years in any location of the study area, and (3) assess the reliability of RDDFEs for ungaged locations through a comprehensive jackknife cross validation.