Completed · Geospatial
Dam-induced flooding in Kwara State, 2018–2025.
Sentinel-1 radar mapping of five dam-release flood events on the River Niger, measuring the flooded cropland and population exposed by each one.
Sentinel-1 radar mapping of five dam-release flood events on the River Niger, measuring the flooded cropland and population exposed by each one.
A multi-temporal radar assessment of five flood events traced to releases from the Jebba and Kainji hydroelectric dams on the River Niger. Flood extents were detected by backscatter change in Google Earth Engine, then overlaid on cropland, population and LGA boundaries to measure what each release put under water.
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Five dam-release events compared side by side: total flooded area, flooded cropland, estimated population exposure, the temporal trend and land-cover composition. Inundation grew from 7 km² in October 2018 to a peak of 255 km² in September 2022, while flooded cropland rose with every event to 122 km² in April 2025, 63.5% of that event's footprint.
Peak 255 km² · Sep 2022WorldPop 2020 population overlaid on each flood mask. The September 2022 release exposed an estimated 24,822 people, the largest of the study period, and the dry-season release of February 2025 still reached 15,623. A second panel sets out the population of each flood-affected LGA.
24,822 exposed · Sep 2022Flooded km² by Local Government Area for every event. Pategi (129.3 km²) and Edu (120.4 km²) held 98% of the September 2022 inundation; then the flood centroid shifted, with Kaiama taking 166.6 km² in April 2025, 87% of that event.
Kaiama 166.6 km² · Apr 2025Two matrices summarise exposure by LGA: how many of the five events reached each one, and the largest area it lost in a single event. Pategi and Edu flooded in every event, the chronic flood core along the Niger floodplain, while Ilorin East and Ilorin West register for the first time in 2025.
Pategi + Edu · 5 of 5 eventsEach affected LGA ranked by its maximum single-event flood area and its event frequency, then graded from Very High to Low, with a separate watch class for urban Ilorin. Pategi, Edu and Kaiama sit in the Very High tier, followed by Moro and Baruten.
3 LGAs rated Very HighWe'll share relevant experience and outline how we'd approach your work.
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