Rainfall intensity–duration–frequency relationships derived from large partial duration series

A procedure is proposed for basing intensity–duration–frequency (IDF) curves on partial duration series (PDS) which are substantially larger than those commonly used for this purpose. The PDS are derived from event maxima series (EMS), composed of the maximum average intensities, over a given duration, determined for all rainfall events recorded at a station. The generalized Pareto distribution (GP) is fitted to many PDS nested within the EMS and the goodness-of-fit is determined by the Anderson–Darling test. The best fitted distribution is selected for predicting intensities associated with the given duration and with a number of recurrence intervals. This procedure was repeated for eleven rainfall durations, from 5 to 240 min, at four stations of the Israel Meteorological Service. For comparison, the GP and the generalized extreme value (GEV) distributions were fitted to annual maxima series (AMS) and the Gumbel and lognormal distributions were fitted to the PDS and to the AMS at these stations.