Mapping Flood Vulnerability in Makurdi Metropolis Using GIS and Remote Sensing

Flooding remains one of the most devastating natural hazards confronting urban settlements in Nigeria's North Central zone, with Makurdi Metropolis in Benue State experiencing repeated inundation events that displace thousands of residents annually. This study maps flood vulnerability across Makurdi using Geographic Information Systems (GIS) and remote sensing data derived from Sentinel-2 satellite imagery acquired between 2020 and 2024. The research integrates elevation data, land cover classification, drainage network analysis, and population density layers to produce a composite flood vulnerability index for the study area. Field verification exercises were conducted across twelve communities to validate remotely sensed classifications against observed flood extents and household exposure indicators. Findings reveal that low-lying riverine communities along the Benue River corridor exhibit the highest vulnerability scores, compounded by inadequate drainage infrastructure and high impervious surface coverage from unplanned urban expansion. The study further identifies seasonal inundation patterns linked to upstream dam releases at Lagdo Dam in Cameroon, which amplify local flood peaks beyond natural catchment thresholds. Recommendations include the designation of permanent flood buffer zones, enforcement of riparian setback regulations, and community-level early warning systems calibrated to upstream discharge monitoring. This research contributes spatially explicit evidence to inform Benue State's urban disaster risk management frameworks and provides a replicable methodology for flood mapping in other riverine towns across the North Central geopolitical zone. Keywords: flood vulnerability, GIS, remote sensing, Makurdi, North Central Nigeria.