Unravelling the Impacts of Climate Variability on Surface Runoff in the Mouhoun River Catchment (West Africa)

• Published in: Land (Basel) Vol. 12; no. 11; p. 2017
• Main Authors: Zouré, Cheick Oumar, Kiema, Arsène, Yonaba, Roland, Minoungou, Bernard
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-11-2023
• Subjects: Agriculture; Annual rainfall; Aquatic resources; Arid regions; Burkina Faso; Climate change; Climate variability; Evapotranspiration; hydrological response; Hydrology; Land use; Management; Mouhoun River Catchment; Rain and rainfall; Rainfall; Rainfall-runoff relationships; River catchments; Rivers; Runoff; Surface runoff; Sustainable development; SWAT model; Water; Water shortages; Water supply; West African Sahel; Burkina Faso; West Africa
• ISSN: 2073-445X; 2073-445X
• DOI: 10.3390/land12112017

This study assesses the impacts of climate variability on surface runoff generation in the Mouhoun River Catchment (MRC) in Burkina Faso, in the West African Sahel. The study uses a combination of observed and reanalysis data over the period 1983–2018 to develop a SWAT model (KGE = 0.77/0.89 in calibration/validation) further used to reconstitute the complete time series for surface runoff. Results show that annual rainfall and surface runoff follow a significant upward trend (rainfall: 4.98 mm·year−1, p-value = 0.029; runoff: 0.45 m3·s−1·year−1, p-value = 0.013). Also, rainfall appears to be the dominant driver of surface runoff (Spearman’s ρ = 0.732, p-value < 0.0001), leading surface runoff at all timescales. Surface runoff is further modulated by potential evapotranspiration with quasi-decadal timescales fluctuations, although being less correlated to surface runoff (Spearman’s ρ = −0.148, p-value = 0.386). The study highlights the added value of the coupling of hydrological modeling and reanalysis datasets to analyze the rainfall–runoff relationship in data-scarce and poorly gauged environments and therefore raises pathways to improve knowledge and understanding of the impacts of climate variability in Sahelian hydrosystems.