Abstract: Makurdi Local Government Area (LGA) is often subjected to annual flood disaster due to its geographical location in terms of its low relief, proximity to River Benue as well as its location at the downstream of Lagdo Dam in Cameroon. Multi-Criteria Decision Analysis (MCDA) was adopted to investigate flood vulnerable areas and elements at risk in Makurdi LGA in Benue State. Topography, landuse and landcover, proximity to River Benue, rainfall and soil textures were integrated and weighted using Analytical Hierarchy Process (AHP) for the assessment of flood vulnerable areas in the Metropolis. Fidi ward was purposively sampled based on its large size and heterogeneous terrain for the assessment of the disaster risk and exposure in the city. Coordinates of one hundred and ninety-one (191) structures in Fidi ward were acquired using GPS Garmin 76 for the investigation of elements at risk in the community. Flood vulnerability of the community were classified into; extremely, highly, moderately and low vulnerability. The results revealed that the valleys of River Benue and other large rivers like River Gwe within the LGA were extremely or highly vulnerable to flood with collective land areas of about 59.91 km2, while the low vulnerable areas were mainly on high relief areas. The wards at the core of the city with very high population were located within extremely or highly vulnerable areas. Other wards with high percentage of land area within extremely and highly vulnerable areas include: Ankpa/Wadata (98.93), Clerk/Market (98.18), Wailomaya (93.35) and North Bank II (92.44). Seventy (70) of the 191 sampled structures were water points, health centres or entrepreneurs which are the essential necessities for human survival. Fifty-one (51) of the 70 structures fell within either extremely or highly vulnerable areas. It was recommended that there should be constant update of geospatial data of the structures within the metropolis for monitoring and assessment of elements at risk for quick government intervention during flood. Relocation of the structures and people in the extremely vulnerable flood areas to safer zones should be enforced if other control methods fail.
Key words: Analytical Hierarchy Process, Flood Disaster Risk, Flood vulnerability, Geospatial Techniques, Multi-Criteria Decision Analysis