Simple Scaling of extreme precipitation in North America
Silvia Innocenti1, Alain Mailhot1, and Anne Frigon21Centre Eau-Terre-Environnement, INRS, 490 de la Couronne, Québec, Canada, G1K 9A9 2Consortium Ouranos, 550 Sherbrooke Ouest, Montrèal, Canada, H3A 1B9
Received: 11 Nov 2016 – Accepted for review: 27 Nov 2016 – Discussion started: 30 Nov 2016
Abstract. Extreme precipitation is highly variable in space and time. It is therefore important to characterize precipitation intensity distributions at several temporal and spatial scales. This is a key issue in infrastructure design and risk analysis, for which Intensity-Duration-Frequency (IDF) curves are the standard tools used for describing the relationships among extreme rainfall intensities, their frequencies, and their durations. Simple Scaling (SS) models, characterizing the relationships among extreme probability distributions at several durations, represent a powerful means for improving IDF estimates. This study tested SS models for approximately 2700 stations in North America. Annual Maxima Series (AMS) over various duration intervals from 15 h to 7 days were considered. The range of validity, magnitude, and spatial variability of the estimated scaling exponents were investigated. Results provide additional guidance for the influence of both local geographical characteristics, such as topography, and regional climatic features on precipitation scaling. Generalized Extreme Value (GEV) distributions based on SS models were also examined. Results demonstrate an improvement of GEV parameter estimates, especially for the shape parameter, when data from different durations were pooled under the SS hypothesis.
Innocenti, S., Mailhot, A., and Frigon, A.: Simple Scaling of extreme precipitation in North America, Hydrol. Earth Syst. Sci. Discuss., doi:10.5194/hess-2016-586, in review, 2016.