Spatial Data Analysis of Flood-Prone Areas in Bayelsa State for Disaster Risk Reduction

Flood disaster risk mapping is a critical tool for emergency preparedness in the Niger Delta, and spatial data analysis provides objective evidence for identifying vulnerable communities requiring priority protection. This study conducted spatial data analysis of flood risk across Bayelsa State, South South Nigeria, using a combination of elevation data, satellite-derived inundation extent from historical flood events, rainfall data, and soil permeability classification. Geospatial layers were integrated in QGIS and ArcGIS, and a composite flood vulnerability index was computed by weighting terrain, hydrology, and social exposure variables. Results identified that 68.4 percent of Bayelsa's land area lies below five metres above sea level, making the state exceptionally flood-exposed. Annual flood events between 2016 and 2022 were mapped using Sentinel-1 SAR imagery, revealing consistent inundation in Kolokuma, Ekeremor, and Southern Ijaw LGAs. High-population density communities in low-lying riverine areas were classified as extreme flood risk zones. The composite index correlated strongly with historical damage records from Bayelsa State Emergency Management Agency. Temporal analysis confirmed a trend toward earlier and longer flood seasons over the seven-year study period. The study provides an evidence base for disaster risk reduction planning. Recommendations include incorporating flood risk maps into Bayelsa State's urban planning approvals, deploying early warning sensors along major flood corridors, and using the vulnerability index to prioritise humanitarian pre-positioning before annual flood seasons.

Keywords: flood risk mapping, spatial analysis, Bayelsa State, disaster risk reduction, satellite imagery