Abstract
Understanding changes in extreme precipitation is critical for enhancing climate resilience, particularly in regions such as West Africa, where communities are highly vulnerable to hydroclimatic extremes. This study examines the spatial and temporal variations in extreme precipitation across West Africa over 1998-2024 using high-resolution satellite data from NASA’s Integrated Multi-satellitE Retrievals for GPM (IMERG) V07B Final Run product. Extreme precipitation is analyzed using daily accumulated precipitation indices, including absolute and threshold-based indices. The Theil-Sen slope estimator and the Mann-Kendall test are applied to identify statistically significant trends at three significance levels. To assess the robustness of the detected trends, results from IMERG are compared with those from the Global Precipitation Climatology Project (GPCP) Version 3.3 Climate Data Record over the same period. The comparison shows generally similar spatial patterns and directions of change between the two datasets across West Africa. Results reveal distinct regional patterns of change. The Guineo-Congolian and Guinean regions, particularly Nigeria’s eastern coast, show significant declines in annual precipitation, along with significant decreases in the frequency and intensity of extreme events. In contrast, the western Sudanian and Sahelian regions, notably southern Mali and Burkina Faso, exhibit increasing trends in both total precipitation and extreme precipitation indices, indicating a shift toward wetter conditions driven by more frequent and intense extreme events. Furthermore, the contribution of extreme precipitation to annual totals varies across climatic zones, with smaller contribution from extreme days at lower latitudes. These findings highlight the importance of regionally tailored climate adaptation strategies for effective flood risk management and sustainable water resources.
Georgios C. Anagnostopoulos
Associate Professor of Electrical Engineering & Computer Science
I lead the Machine Learning Research Group at FIT.