Use of Partial Duration Series for Single-Station and Regional Analysis of Floods

Abstract

Techniques for flood estimation at a single station and in a regional context using partial duration series are analyzed. This involves using a Poisson distribution to describe the occurrence of floods, while the generalized Pareto distribution is used for flood magnitudes. The fitting technique used is that of probability-weighted moments, and the regionalization scheme adopted is the index flood method. The problem of threshold choice is also analyzed. Examples given throughout the paper use partial-duration series abstracted from daily hydrographs recorded at hydrometric stations in the province of Ontario, Canada.