Yira Yacouba^1,, Bossa Yaovi Aymar², Ngom L. A. L. C. A. Guedji³, Hounkpè Jean², Hounkpatin L. Ozias⁴, Mouhamed Idrissou⁵, Sintondji O. Luc²

This study assesses the impact of future climate change on three water related ecosystem services (WRES) in the Dano catchment. The conceptual rainfall-runoff model HBV light was successfully calibrated (NSE = 0.945, R² = 0.945, and KGE= 0.948) and validated (NSE = 0.648, R² = 0.798, and KGE= 0.551) and demonstrated a good agreement between observed and simulated variables. The projected climate change signal in the catchment was analyzed using the WASCAL high-resolution regional climate simulations (HadGEM2-ES and GFDL-ESM2M under RCP 4.5) between a refence period (1985-2005) and two future periods (2020-2049 & 2070-2099). Compared to the reference period, both climate models show an increase in temperature of +1.9 to +2.8 °C by 2020-2049, and at the end of the century 3.2 to 5.4 °C. Precipitation trends of + 10 to +30 % in the middle of the century and between +37 to +51.4% towards 2100 are projected. The projected annual discharges change signals show an increase of +25 % to +68 % by 2049, while at the end of the century this increase exceeds +80.65. The simulated hydrological changes were translated into changes in WRES provision (hydropower, domestic water consumption, and ecological flow). The projected discharge increase will translate in an increase of hydropower generation potential but this increase in discharge will not be enough to meet future additional domestic water demand. Domestic water supply will decrease because of population growth. Therefore, the projected increase in future discharge will not be sufficient to counterbalance the additional water demand associated to population development.

Climate change, hydrological modelling, Water related ecosystems services, HBV-light, Burkina Faso