A derived hood frequency distribution (DFFD) combines a stochastic rainfall
model with a deterministic rainfall-runoff model to obtain a physically ba
sed probability distribution of flood discharges. Previous DFFD studies hav
e either assumed that rainfall intensity and duration an independent or neg
atively correlated. This study is more general than previous studies becaus
e it accommodates both positive and negative correlations between rainfall
intensity and duration. Rainfall-runoff processes are modeled using a phi-i
ndex infiltration model and a geomorphoclimatic instantaneous unit hydrogra
ph. Applications to four Indian watersheds and one US watershed demonstrate
s that (1) the correlation of rainfall intensity and duration has an import
ant impact on the DFFD and (2) the DFFD provides a potentially useful alter
native for estimating hood flow quantiles at ungaged sites. (C) 2000 Elsevi
er Science B.V. All rights reserved.