Ansoumana Bodian

ABSTRACT In West Africa, hydrological variability remains poorly understood in many watersheds where observation networks are sparse. After gap-filling gauge data with remote sensing datasets and daily rainfall-runoff modelling, the hydroclimatic variability in upper catchments of the Gambia, KolibaCorubal, KayangaGeba, and Senegal rivers is investigated. CHIRPS rainfall and GLEAM evapotranspiration are used to simulate discharge in 38 sub-basins over 1981–2023 with the GR4J model.

1 Introduction West Africa is highly vulnerable to climate change. The region is expected to experience unprecedented changes in both temperature and extreme precipitation patterns (IPCC 2014; Niang et al. 2014; Gautier, Denis, and Locatelli 2016; Sylla et al. 2016; Serdeczny et al. 2017; Adefisan 2018; Ahokpossi 2018; Akinseye et al. 2020; Ilori and Ajayi 2020; Muthoni 2020; Opoku et al. 2021).