Francesco Uboldi     CONTACT BY E-MAIL

Hydrology: rainfall annual maxima frequency characterization

Depth-Duration-Frequency (DDF) curves are a probability map for rainfall annual maxima in a given site. For a given return period T [years], the corresponding DDF curve gives the raindepth threshold hT [mm] which is exceeded with frequency 1/T, as a function of event duration D [hours].
DDF curves are traditionally estimated on a particular observational site from the time series of rainfall annual maxima there recorded. A parameter estimation is performed on the GEV (Generalized-Extreme-Value) distribution, and the GEV parameters are inserted into a more or less complicated analytical expression for the DDF curves. The "spatial bootstrap" approach (Uboldi et al., 2014) performs parameter estimation on a geographic area by making use of all relevant data at each target point, combining regionalisation and spatial variation.
Works on rainfall annual maxima statistics:

Parameters and quantiles estimated by means of the spatial bootstrap technique are available to users in the web-GIS (Geographic Information System) of the hydrographic service of ARPA Lombardia (there, follow: "Linee segnalatrici 1-24 ore - P.STRADA")

SEMINAR 02 May 2016 at ARPA Emilia-Romagna Bologna, Italy: "Variazioni dei massimi di precipitazione in area prealpina — Evidenza di cambiamento locale nel tempo della climatologia dei massimi annuali di precipitazione" (mostly in Italian: Time variation of precipitation annual maxima in prealpine area in Italy)

Besides, you may also want to have a look at maps of hourly and 24h-accumulated precipitation obtained as analysis of raingauges observations and integration of raingauge observations and weather radar estimates (sorry, these web pages are in Italian).