FLOOD RISK ASSESSMENT AND VULNERABILITY MAPPING USING ANALYTICAL HIERARCHY PROCESS AND GEOGRAPHIC INFORMATION SYSTEM: A CASE STUDY OF MINNA, NIGER STATE

Mubaraq Ali; Ibrahim Olayinka  Jimoh; Isa Adekunle  Hamid-Mosaku; Emmanuel G Ayodele; Abidemi Waheed  Atoyebi; Kazeem Adewunmi  Raheem

Mubaraq Ali Department of Civil Engineering, School of Infrastructure, Process Engineering and Technology, Federal University of Technology, Minna, Niger State, Nigeria
Ibrahim Olayinka Jimoh Department of Civil Engineering, School of Infrastructure, Process Engineering and Technology, Federal University of Technology, Minna, Niger State, Nigeria
Isa Adekunle Hamid-Mosaku Department of Surveying and Geoinformatics, University of Lagos, Akoka, Yaba, Lagos State, Nigeria
Emmanuel G Ayodele Department of Surveying and Geoinformatics, University of Lagos, Akoka, Yaba, Lagos State, Nigeria
Abidemi Waheed Atoyebi Department of Surveying and Geoinformatics, University of Lagos, Akoka, Yaba, Lagos State, Nigeria
Kazeem Adewunmi Raheem Department of Civil & Environmental Engineering, University of Port Harcourt, Choba, Port Harcourt, Rivers State, Nigeria.

Keywords: Minna, AHP, Flood-risk, Regions, Driving criteria, Environmental issues

Abstract

Flooding is one of the most damaging disasters worldwide, and natural and human activities influence it. It has caused destruction and loss of lives and properties, which calls for spatial scope and mitigation methods for a better understanding. This research aims to map and identify flood risk regions in Minna, Niger State, using a multi-criteria decision-making tool – the Analytical Hierarchy Process (AHP) and Geographic Information System (GIS). The AHP is the foundation for the study in determining and integrating the weighted percentage of flood criteria within the ArcGIS interface. The criteria considered for this research include Elevation, Topographic Wetness Index (TWI), Slope, Precipitation, Drainage Density, Soil Type, Proximity to River, and Land Use Land Cover (LULC). The resultant AHP flood risk map shows that 22.25% of the study area is at high and very high risk of flooding, 53.7% has a moderate susceptibility level, while 24.05% is at low and very low risk of flooding. Low slopes, high drainage density, and built-up regions are observed to be characteristic of these communities, which are at a very high risk of flooding. The result of the analysis urges the authorities in Minna, Niger State, to devise appropriate plans for potential floods in the future, such as proper maintenance of the drainage system and creating awareness of flood risk.