Tales of the Wakeby tail and alternatives when modelling extreme floods

Abstract

Estimation of return levels, based on extreme-value distributions, is of importance in the earthand environmental sciences. The selection of an appropriate probability distribution is crucial.The Wakeby distribution has shown to be an interesting alternative. By simulation studies, weinvestigate by various means of minimum distance to distinguish between common distributionswhen modelling extreme events in hydrology. Estimation of parameters is performed by L-moments.Moreover, time series of annual maximum floods from major unregulated rivers in Northern Swedenwere analysed with respect to fitting an appropriate distribution. The results of the simulationstudy shows that the Wakeby distribution has the best fit of the tail for a wide range of samplesizes. For the analysis of extreme floods, the Wakeby distribution is in the majority of cases thebest fit by means of minimum distance. However, when considering estimation of return levels bycompeting distributions, results can vary considerably for longer return periods.

Keywords

Wakeby distribution; GEV distribution; L-moments; distance measures; floods.

Published in

Revstat Statistical Journal
2024, volume: 22, number: 1, pages: 45–60

SLU Authors

• Rydén, Jesper

  • Department of Energy and Technology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Probability Theory and Statistics

Publication identifier

• DOI: https://doi.org/10.57805/revstat.v22i1.454

Permanent link to this page (URI)

https://res.slu.se/id/publ/128548