Ndiaye P. M., Ogilvie Andrew, Bodian A., Descroix Luc, Legay T., Guillet R. (2025). Hydrological variability of large rivers in West Africa : gap-filling with Earth observations and daily rainfall-runoff modelling. Hydrological Sciences Journal, Early access, p. [19 p.]. ISSN 0262-6667.
Titre du document
Hydrological variability of large rivers in West Africa : gap-filling with Earth observations and daily rainfall-runoff modelling
Ndiaye P. M., Ogilvie Andrew, Bodian A., Descroix Luc, Legay T., Guillet R.
Source
Hydrological Sciences Journal, 2025,
Early access, p. [19 p.] ISSN 0262-6667
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. Robust performance observed in 34 basins (KGE > 0.5) confirms the effectiveness of the approach even at a daily time step in poorly gauged basins. A dry period (1981-1993), followed by two distinct wet periods (1994-2007, 2008-2023) are identified using standardized precipitation index (SPI), standardized streamflow index (SSI) and the non-parametric Mann-Kendall test. Increased variability in extreme flows and a later peak flood are observed in some basins. Understanding non-stationarity in West African basins is essential to support stakeholders in defining adequate river basin development strategies.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
;
Hydrologie [062]
;
Bioclimatologie [072]
Description Géographique
AFRIQUE DE L'OUEST ; GAMBIE ; GUINEE ; GUINEE BISSAU ; SENEGAL ; MAURITANIE ; MALI ; GAMBIE COURS D'EAU ; KAYANGA GEBA COURS D'EAU ; KOLIBA CORUBAL COURS D'EAU ; SENEGAL COURS D'EAU ; BASSIN VERSANT
