Assessment of climate change forecasts for the Agnéby watershed, south-eastern Ivory Coast

This study aims to characterize the impacts of climate change by the years 2050 and 2080 in the Agnéby watershed, located in southeastern Côte d'Ivoire. The methodology employed involves extracting key climate variables—specifically precipitation and temperature—from regional climate models. These data were then corrected to reduce biases using a linear regression method. This correction was applied to a historical reference period (1976–2005) as well as to two future climate projections corresponding to the time intervals 2025–2054 and 2055–2084. Data analysis reveals a decrease in average annual precipitation ranging from 0.27% to 0.72% under the RCP4.5 scenario. In contrast, the RCP8.5 scenario projects an increase of 0.2% followed by a decrease of 0.24% compared to the baseline period. Furthermore, temperatures are projected to rise by 1.18°C by 2050 and by 2.06°C by 2080, again according to the RCP4.5 scenario. Between now and the 2050s and 2080s, temperatures will rise by +1.74 °C and +2.47 °C, respectively. According to the RCP8.5 scenario, these increases could reach between +2.2 °C and +3.1 °C by 2080. During these same periods, projections indicate increases ranging from +2.35 °C to +3.78 °C. This climate change will lead to a gradual decline in surface water resources, exacerbated by the effects of climate change. This decline could jeopardize agricultural systems, a worrying situation since nearly two-thirds of the population depends on traditional agriculture for their livelihood.