Data & Methodology
Technical Architecture, Spatial Layer Provenance & Model v0.3 Specification
Flood Risk Susceptibility Model (v0.3)
Multi-criteria spatial evaluation combining physical & real-time telemetry
The FEWS Nigeria model computes composite flood risk scores for all 774 Local Government Areas (LGAs) by weighting baseline static environmental factors against dynamic satellite observation bulletins.
1. Baseline Environmental Factors
Elevation (DEM)SRTM 30m
Topographic elevation from NASA SRTM digital elevation model. Lowland riverine areas receive higher susceptibility weighting.
River ProximityHydroSHEDS v1
Euclidean distance buffers to major river networks (Niger, Benue, Kaduna, Imo, Cross River basins).
Historical Flood Frequency2012–2025 Archive
Historical inundation frequency compiled from NIHSA annual flood reports and MODIS/Sentinel archives.
Precipitation AnomalyCHIRPS 0.05°
Cumulative 7-day rainfall totals relative to 30-year climate normals.
2. Active Dataset Inventory & Provenance Rules
| Layer Name | Provider / Sensor | Update Cadence | Provenance Tag |
|---|---|---|---|
| State & LGA Boundaries | GRID3 Nigeria / OSGOF | Static (2024) | Calculated |
| Synthetic Aperture Radar (SAR) Inundation | Sentinel-1 (ESA via GEE) | 6–12 Days | Observed |
| FEWS Vulnerable Locations | Ministry Inventory (2,000 pts) | Annual | Observed |
| Schools at Risk Exposure | GRID3 + Bulletin Exposure Join | Weekly Bulletin | Estimated |
| River Discharge Forecasts | GloFAS ECMWF Ensemble | Daily (00:00 UTC) | Forecast |
Strict Labeling Rule: Every figure displayed in the platform or generated by the AI assistant is strictly tagged as Observed (direct sensor/satellite), Calculated (zonal statistic), Modelled (computed risk score), or Estimated (interpolated depth).