Sarr M.A., Seidou O., Tramblay Yves, El Adlouni S. (2015). Comparison of downscaling methods for mean and extreme precipitation in Senegal. Journal of Hydrology.Regional Studies, 4 (part B), p. 369-385. ISSN 2214-5818.
Titre du document
Comparison of downscaling methods for mean and extreme precipitation in Senegal
Année de publication
2015
Type de document
Article
Auteurs
Sarr M.A., Seidou O., Tramblay Yves, El Adlouni S.
Source
Journal of Hydrology.Regional Studies, 2015,
4 (part B), p. 369-385 ISSN 2214-5818
Study region : The study considers six precipitation stations located in Senegal, West Africa. Senegal is located in the Sahel, an area that is threatened by climate variability and change. Both droughts and extreme rainfall have been an issue in recent years. Study focus : Two different statistical downscaling techniques were applied to the outputs of four regional climate models at six selected precipitation stations in Senegal. First, the delta-change method was applied to the mean annual precipitation as well as the 5, 10, 20, 50 and 100-year return period daily precipitation events. Second, a quantile-quantile transformation (QQ) was used to downscale the monthly distributions of precipitation simulated by regional climate models (RCMs). The 5, 10, 20, 50 and 100-year daily precipitation events were afterward calculated. All extreme events were calculated assuming that maximum annual daily precipitations follow the generalized extreme value (GEV) distribution. The two-sided Kolmogorov-Smirnov (KS) test was finally used to assess the performance of the quantile-quantile transformation as well as the GEV distribution fit for the annual maximum daily precipitation. New hydrological insights for the region : Results show that the two downscaling techniques generally agree on the direction of the change when applied to the outputs of same RCM, but some cases lead to very different projections of the direction and magnitude of the change. Projected changes indicate adecline in mean precipitation except for one RCM over one region in Senegal. Projected changes in extreme precipitations are not consistent across stations and return periods. The choice of the downscaling technique has more effect on the estimation of extreme daily precipitations of return period equal or greater than ten years than the choice of the climate models.
Plan de classement
Analyse, évolution des climats [021CLIMAT01]
;
Répartition spatio-temporelle des précipitations [062MECEAU01]
