CGRG Bibliography of Canadian Geomorphology
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Author : Alila, Y.
Date : 1999.
Title : A hierarchical approach for the regionalization of precipitation annual maxima in Canada.
Publication : Journal of Geophysical Research - Atmospheres
Issue : 104(D24):
Page(s) : 31,645 -31,656.
Abstract
The L-moments are used in the three stages of regional frequency analysis: the delineation of homogeneous regions, the identification of a regional parent distribution, and the estimation of distribution's parameters. Numerical analysis is conducted on 5 minutes to 24 hours annual rainfall extremes from 375 precipitation gaging stations in Canada. The numerical analysis concluded that Canada could be considered as single homogeneous region in which the L-skewness and L-kurtosis display no significant spatial variability. Also, based on mean annual precipitation (MAP), Canada can be divided into climatologically homogeneous sub-regions, in which the L-coefficient of variation is virtually constant. The parent distribution was identified as the general extreme value (GEV), the parameters of which depend on the MAP and storm duration. A hierarchical regional approach is proposed for fitting the identified GEV distribution, where the L-skewness, L-coefficient of variation, and mean are estimated on a regional, sub-regional, and single site basis, respectively. Monte Carlo simulations indicate that design storms estimated by the proposed hierarchical approach are substantially more accurate than those estimated by the single site method. The simulations also demonstrate that the proposed hierarchical approach makes the estimation of design storms at ungauged sites less dependent on the availability of precipitation data.
Bibliography of Canadian Geomorphology