GIS-Based Flood Risk Mapping and Mitigation Planning in Ningi Local Government Area, Bauchi State, Nigeria

Abstract

Flooding remains a major environmental hazard in Nigeria. This study assessed flood patterns and spatial susceptibility in Ningi Local Government Area (LGA), Bauchi State, using Geographic Information System (GIS) techniques. Digital Elevation Models (DEMs), drainage analysis, and spatial mapping were applied to examine terrain and drainage characteristics, delineate flood-prone locations, and assess deficiencies in existing drainage infrastructure. Flooding reflects interacting physical and human factors. Topography-induced surface runoff contributes to the concentration and movement of stormwater, while inadequate drainage infrastructure constrains its conveyance. Settlement along waterways increases exposure to flooding, and poor waste disposal practices may obstruct drainage pathways and worsen local inundation. Together, these conditions point to the need for spatially informed interventions that address both runoff management and patterns of human settlement. To mitigate flood impacts, the study proposes a phased strategy comprising canal construction, earth dam development, and land-use regulation. Phasing is intended to support the orderly implementation of structural measures alongside controls on development in vulnerable areas. GIS provides a practical decision-support framework for identifying flood-prone areas, relating susceptibility to terrain and drainage conditions, and informing the prioritization of mitigation actions. The study concludes that applying GIS to flood assessment in Ningi can support more sustainable flood management by linking spatial evidence with infrastructure planning and land-use decisions. The findings offer a basis for local authorities to target interventions, improve drainage planning, and guide settlement regulation in areas exposed to flooding, while recognizing that effective risk reduction requires coordinated attention to topography, infrastructure, waterways, and waste management.