Local climate change signals and changes in climate extremes in a typical Sahel catchment: The case of Dano catchment, Burkina Faso
Gloria C. Okafor, Isaac Larbi, E. C. Chukwuma, Clement Nyamekye, Andrew Manoba Limantol, Sam-Quarcoo Dotse
Abstract
This study investigated the changes in the climate and the spatiotemporal variations in climate extreme indices of the Dano catchment in Burkina Faso using historical data for the period 1981–2010 and projected for the period 2020–2049. Rainfall and temperature simulations from two RCMs under two Representative Concentration Pathways (RCP 4.5 and RCP 8.5) involved in the CORDEX-Africa project were used in this study. The study found that the climate change signal in the future based on the ensemble mean of the RCMs indicates a decrease in the mean annual rainfall by 25.2% and 25.6% for RCP4.5 and RCP8.5 respectively. A clear temperature increase of about 1.3 °C and 1.5 °C is projected for the catchment using the models. The future rainfall trend projections mostly exhibited a mixed magnitude of increasing and decreasing trends for most areas, indicating no clear pattern of change in the extreme rainfall indices. A non-significant increase in heavy precipitation day events is however projected for the period under RCP 4.5. Projected changes in consecutive dry (wet) days are not significant. Temperature extreme projections showed increasing and decreasing trends in the warm and cold indices respectively, suggesting a warmer climate in the near future. Our study reveals potential climate extremes over the catchment stronger in RCP8.5 which is in agreement with the twenty-first-century warming expected for the region. The spatial distribution investigation highlights extreme dry events across the catchment considerably in the Northern areas. This study finds application for decision-makers to develop more suitable climate change and extremes adaptation strategies for agriculture and water supplies.