The annual maximum amount of rainfall over a fixed duration, area, and level of occurrence is generally described by intensity–duration–area–frequency (IDAF) curves. The annual maxima analysis can provide poor estimates of quantiles associated to high return periods when the sample size is short. Here, IDAF curves are derived analytically from the statistical properties of event maxima of rainfall intensity in area and duration, which are assumed scale invariant in time and space and Lognormal distributed, with a Poissonian chronology of rain events. The event maxima methodology is applied to the Reno basin, Emilia-Romagna, Italy, and its IDAF curves are compared in terms of goodness-of-fit to those obtained through the annual maxima analysis, showing better performances. In particular, we found that the absolute difference, in %, between model and data, is 20% in average, and 7% in standard deviation, using the method based on the event maxima analysis, while it is 27% in average, and 12% in standard deviation, using the method based on the annual maxima analysis.

Analytical derivation of rain intensity-duration-area-frequency relationships from event maxima

DE MICHELE, CARLO;ROSSO, RENZO
2011-01-01

Abstract

The annual maximum amount of rainfall over a fixed duration, area, and level of occurrence is generally described by intensity–duration–area–frequency (IDAF) curves. The annual maxima analysis can provide poor estimates of quantiles associated to high return periods when the sample size is short. Here, IDAF curves are derived analytically from the statistical properties of event maxima of rainfall intensity in area and duration, which are assumed scale invariant in time and space and Lognormal distributed, with a Poissonian chronology of rain events. The event maxima methodology is applied to the Reno basin, Emilia-Romagna, Italy, and its IDAF curves are compared in terms of goodness-of-fit to those obtained through the annual maxima analysis, showing better performances. In particular, we found that the absolute difference, in %, between model and data, is 20% in average, and 7% in standard deviation, using the method based on the event maxima analysis, while it is 27% in average, and 12% in standard deviation, using the method based on the annual maxima analysis.
2011
File in questo prodotto:
File Dimensione Formato  
JoH_DeMichele_et_al2011.pdf

Accesso riservato

: Post-Print (DRAFT o Author’s Accepted Manuscript-AAM)
Dimensione 655.64 kB
Formato Adobe PDF
655.64 kB Adobe PDF   Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11311/609199
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 22
  • ???jsp.display-item.citation.isi??? 21
social impact