Assessing climate change impact on the hydropower potential of the Bamboi catchment (Black Volta, West Africa)

Yacouba Yira,Aymar Yaovi Bossa,Jean Hounkpè,Seyni Salack,Tariro Cynthia Mutsindikwa

doi:10.5194/piahs-384-349-2021

Abstract

Abstract. This study evaluates the impact of future climate change (CC) on the hydropower generation potential of the Bamboi catchment (Black Volta) in West Africa using a conceptual rainfall-runoff model (HBV light) and regional climate models (RCMs)–global climate models (GCMs). Two climate simulation datasets MPI-ESM-REMO (CORDEX) and GFDL-ESM2M-WRF (WASCAL) under RCP4.5 were applied to the validated hydrological model to simulate the catchment runoff. Based on reference and future simulated discharges, a theoretical 1.3 MW run of river hydro power plant was designed to evaluate the hydropower generation. Hydrological and hydropower generation changes were expressed as the relative difference between two future periods (2020–2049 and 2070–2099) and a reference period (1983–2005). The climate models' ensemble projected a mean annual precipitation increase by 8.8 % and 7.3 % and discharge increase by 11.4 % and 9.735 % for the 2020–2049 and 2070–2099 periods respectively (for bias corrected data). On the contrary an overall decrease of hydropower generation by −9.1 % and −8.4% for the 2020–2049 and 2070–2099 periods was projected respectively. The results indicate that projected increases in discharge should not solely be considered as leading to an increase in hydropower potential when prospecting climate change impact on hydropower.

Highlights

Hydropower is the leading source of renewable energy in West Africa (Hamududu et al, 2012)
Several studies (e.g. Obahoundje, 2015) have already assessed the impacts of climate change (CC) on water resources in West Africa not much work was done on its impacts on hydropower potential
Both Oyerinde et al (2016) and Obahoundje (2015) undertook researches on the potential impact of CC on hydropower generation at the Kainji dam and the Bui dam (Black Volta basin) respectively; and results showed that while CC is projected to decrease the hydropower potential of Bui, the opposite is expected for Kainji

Summary

Introduction

Hydropower is the leading source of renewable energy in West Africa (Hamududu et al, 2012). Obahoundje, 2015) have already assessed the impacts of CC on water resources in West Africa not much work was done on its impacts on hydropower potential Both Oyerinde et al (2016) and Obahoundje (2015) undertook researches on the potential impact of CC on hydropower generation at the Kainji dam (the Niger Basin) and the Bui dam (Black Volta basin) respectively; and results showed that while CC is projected to decrease the hydropower potential of Bui, the opposite is expected for Kainji. A strong reduction in the rainfall occurrence has been experienced in the Bamboi catchment (Black Volta) since 1960s, and notably during the 1973/1974 and 1983/1984 droughts (Boadi et al, 2017) These reductions have led to strong fluctuations in the river discharge with generally a negative trend from 1960–2000. The aim of this research is to assess the impacts of CC on hydropower potential of Bam-

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Conclusion