Le Lay M. auteur aut IRD Galle Sylvie auteur aut IRD text journalArticle fre text/pdf born digital access West African rainfall is characterized by a strong variability, both at decadal and interannual scales. In order to quantify the hydrological impacts of such a variability, analysis of rainfall patterns at fine scales is highly essential. This diagnostic study aims to characterize the Sudanese rainfall regime at hydrological scales, using a raingauge data set collected on the upper Oueme River catchment (Benin) between 1950 and 2002. A long-term drought is observed during the 1970s and 1980s, as in the Sahel. However, the interannual variability remains significant in the Sudanese region. The study of the seasonal cycle, based on the distinction between the oceanic and continental monsoon regimes, shows that the majority of rainfall changes occur in the continental regime. On the one hand, the rainfall peak associated with this regime that has been observed for the last 50 years has occurred increasingly earlier in the season. On the other hand, the annual rainfall deficit is mainly linked to the decrease in the number of large events during the continental part of the season. specialized catchment Sudanese climate rainfall deficit monsoon precipitation West Africa 062 50 3 509-524 2005 0262-6667 https://www.documentation.ird.fr/hor/fdi:010068410 10.1623/hysj.50.3.509.65029 0262-6667 [F B010068410] https://www.documentation.ird.fr/hor/fdi:010068410 https://www.documentation.ird.fr/intranet/publi/depot/2016-10-20/010068410.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2006-03-29 2017-11-02 fdi:010068410 fre