Step 1 of 10 · River flood depths
Flood hazard
Global river flood-depth maps from the EU Joint Research Centre give modelled water depth for floods from 1-in-10 to 1-in-500 years on a common 90 m grid across Ghana. A 1-in-100-year flood has a 1% chance of happening in any year.
5flood return periods, 1-in-10 to 1-in-500 years
Inputs, process, outputs and limitation
Inputs
- JRC Global River Flood Hazard Maps v2 (Dottori et al., 2024): ~90 m depth rasters produced by JRC with LISFLOOD hydrology and LISFLOOD-FP inundation; RP10, 50, 100, 200, 500 used
- Ghana district boundaries (admin level 2, 260 polygons)
Process, as coded
Tiles mosaicked and reprojected to UTM 30N (EPSG:32630) with GDAL; read with rasterio (read_raster(), nodata set to 0). Alternatives compared: WRI Aqueduct (~900 m) and UNEP/CIMA GIRI (90 m).
Outputs
Five aligned depth rasters (jrc_rp{RP}_mosaic_epsg32630.tif), each 7,939 × 5,502 cells at 90 m.
Limitation
Published JRC outputs were used as given, with no local hydraulic model, so channels, defences and urban drainage are not represented. River flooding only.

