Stationary vs. Non-Stationary Modelling of Flood Frequency Distribution across North-West England

Sina Hesarkazzazi, Rezgar Arabzadeh, Mohsen Hajibabaei, Wolfgang Rauch, Thomas Kjeldsen, Ilaria Prosdocimi, Attilio Castellarin, Robert Sitzenfrei

Research output: Contribution to journalArticlepeer-review

Abstract

Recent extraordinary flood events occurred in north-west England, with several severe floods in Cumbria, Lancashire and the Manchester area in 2004, 2009 and 2015. These clustered extraordinary events have raised the question of whether any changes in the magnitude and frequency of river flows in the region can be detected. For this purpose, the annual maximum series of 39 river gauging stations in the study area are analysed. In particular, non-stationary models which include time, annual rainfall and annual temperature as predictors are investigated. Most records demonstrate a marked non-stationary behaviour and up to a 75% increase in flood quantiles estimates during the study period. Annual rainfall explains the largest proportion of variability in the peak flow series relative to other predictors considered in our study, providing practitioners with a useful framework for updating flood quantile estimates based on the dynamics of this highly accessible and informative climate indicator.
Original languageEnglish
JournalHydrological Sciences Journal
Publication statusAcceptance date - 7 Dec 2020

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