Linking Earth Observation and Precipitation In-Situ Data in the Sirba River Basin in West Africa

Floods have caused substantial loss of life and economic damages in West Africa, with a marked increase of extremes over the past decades. These flood events are largely driven by frequent extreme local rainfall. The sparse meteorological stations in Burkina Faso contain data gaps that limit effective monitoring of rainfall. This study fills the gap by integrating satellite data with in-situ precipitation measurements. This study assesses spatio-temporal correlations between cloud coverage and reservoir surface water areas extracted from Sentinel-2 to in-situ rainfall historical data complemented with spatially explicit gridded meteorological products, including ERA5 and CHIRPS. In-situ precipitation shows a strong correlation with cloud coverage (Mean r = 0.65), better agreements with ERA5 (r = 0.83) and CHIRPS (r = 0.91), and a timelagged correlation with surface water areas. A developed open-access app (Abraiz, 2026) provides insights for realtime dynamics of the cloud coverage, precipitation, and surface water area of reservoirs in the Sirba River basin with potential applicability in other data-scarce regions.