Flood Susceptibility Assessment of Lagos State, Nigeria using Geographical Information System (GIS)-based Frequency Ratio Model

Flood is a common disaster affecting the lives and properties of humans. It has history causing great damage to infrastructure; disrupt transportation, also, greater degree flooding can lead caving in earth landslides. Oftentimes, Lagos state, economic capital Nigeria been subjected owing heavy rainfall coupled with other causative factors. This study aims prepare flood susceptibility map state using frequency ratio model Geographic Information System (GIS). In this paper, we have considered ten salient contributing factors flooding, they are; slope, curvature, drainage proximity, density, soil type, average annual rainfall, topographic wetness index, land use & cover, normalized difference vegetation elevation delineate area susceptible flooding. The inventory was prepared from 100 points identified news reports, Google Earth Imagery further divided into 70 for training 30 testing model. result shows that 12.54% 11.62% total very high low levels susceptibility, respectively. Area Under Curve used validate found perform satisfactorily success rate 64% prediction 61%. work necessary input mitigating hazards will serve good purpose making decisions city planners government.