A synthetic view of rainfall intensification in the West African Sahel

Abstract The West African Sahel has been facing for more than 30 years an increase in extreme rainfall with strong socio-economic impacts. This situation challenges decision-makers to define adaptation strategies a rapidly changing climate. present study proposes (i) quantitative characterization of the trends at regional scale, (ii) translation into metrics that can be used by hydrological risk managers, (iii) elements understanding link between climatology and mean rainfall. Based on non-stationary statistical model applied in-situ daily data over period 1983–2015, we show region-wide increasing trend is highly significant. change value distribution reflects both variability, producing 5%/decade intensity whatever return period. framework provides operational revising design methods hydraulic structures which most often assume stationary Finally, shows annual maxima attributable stronger storm intensities (80%) frequent occurrences (20%), reflecting major regime shift comparison those observed region since 1950.