A scaling model of depth-duration-frequency relationship for the analysis of extreme rainfalls in an alpine region

The relationship between rainfall depth, duration and frequency, represented in a compact form by the depth-duration-frequency (DDF) curve, has been of considerable interest to practising engineers and hydrologists for over a century. Recent research sought to apply the scaling hypotheses to annual maximum series of rainfall depth for different rainfall duration. It is shown here that, based on the empirically observed scaling properties of rainfall and some general assumptions about the cumulative distribution function for the annual maximum of the rainfall depth, it is possible to derive a simple DDF relationship. This general framework provides a basis for the generation of maps that can be used to infer DDF curves at any point of a particular area. Data from a dense raingauge network in a mountainous region in north-eastern Italy (the Trentino Province) are used to clarify the methodology for the construction and regionalization of the DDF relationship