Estimation des pluies exceptionnelles journalières en zone tropicale: Cas de la Côte d'Ivoire par comparaison des lois lognormale et de Gumbel

Abstract

First, extreme annual daily rainfalls from 34 rainfall stations of the Ivory Coast for the period 1947-195 were analysed. Then, the data were fitted to either the Gumbel or lognormal extreme value distribution, selected according to the criteria of the Anderson test. This step helps identify the zone of applicability of each fitting model and to evaluate the impact of the exclusive use of Gumbel distribution in the country during civil engineering studies. The cartography of the quantiles of return period from 2 to 100 years derived by means of kriging indicates that the lognormal distribution suits the sets of climatic regimes of Equatorial transitional type and weakened Equatorial transitional type in the western and central parts of the country. Gumbel distribution appears well adapted to both mountainous and Equatorial transition regimes and weakened Equatorial transition regimes, the latter especially in the north and a small portion of the southern part of the country. Copyright © 2007 IAHS Press.