Our geospatial team has mapped five dam-release flood events in Kwara State using Sentinel-1 radar imagery processed in Google Earth Engine. The figures are now on our Our Works page, where each plate opens full size.
What the maps show
Radar sees through cloud, which matters during the rainy season when optical imagery is unusable. Comparing backscatter before and after each release separates flood water from dry ground, and the resulting flood masks were overlaid on cropland, population and local government boundaries.
- Inundation grew from 7 km² in October 2018 to a peak of 255 km² in September 2022.
- Flooded cropland rose with every event, reaching 122 km² in April 2025.
- Pategi and Edu flooded in all five events, marking a chronic flood core on the Niger floodplain.
- In April 2025 the flood centroid shifted to Kaiama, which took 166.6 km².
Why it matters
The releases from the Jebba and Kainji hydroelectric dams are predictable in a way that rainfall is not, so the communities downstream can be warned. Maps of this kind support advance notification of planned releases, agricultural compensation schemes and the placement of community early warning systems.
If you would like this analysis extended to another state or river basin, get in touch.