Mapping and Monitoring Oil Spill Extents in Ogoni Land, Rivers State Using SAR Imagery

Oil spills in Ogoni Land have caused some of the most extensively documented environmental damage in Nigeria's oil-producing region, with persistent contamination affecting agricultural land, water resources, and community health. This study maps and monitors the spatial extents of oil spill events in Ogoni Land, Rivers State, using Synthetic Aperture Radar imagery from Sentinel-1. The high backscatter contrast between oil films on water surfaces and clean water bodies enables delineation of spill coverage using threshold-based classification of SAR sigma-naught values. Multi-temporal SAR image analysis tracks the spatial dynamics of five documented spill events between 2021 and 2024, providing area estimates and spread velocity calculations. Results are validated against NOSDRA field assessment reports and community documentation from local NGOs. Mapping accuracy for open-water oil detection exceeds ninety percent, but accuracy is reduced in vegetated swamp areas where oil penetration below the canopy limits SAR backscatter response. The study contributes a radar-based monitoring workflow applicable to cloudy conditions that frequently inhibit optical sensor deployment in the Niger Delta. Spatial outputs are shared with the National Oil Spill Detection and Response Agency and Ogoni Land restoration authorities to support targeted remediation planning. Keywords: oil spill, SAR imagery, Sentinel-1, Ogoni Land, NOSDRA.