An Original Computational Framework for Multi-Hazard Infrastructure Risk Assessment in Nigeria’s Urban Areas

Nigerian urban infrastructure is exposed to multiple concurrent natural and human-induced hazards including flooding, slope failure, soil liquefaction, strong wind, and industrial accidents, yet existing risk assessment frameworks treat these hazards independently, failing to capture correlation, cascade, and compound effects. This study develops an original computational multi-hazard infrastructure risk assessment framework applicable to Nigerian urban areas. The framework integrates probabilistic hazard models (developed for each hazard type using Nigerian climate and geological data), exposure and vulnerability models (calibrated to Nigerian infrastructure typologies and construction standards), and a multi-hazard correlation and cascade interaction model implemented within a Monte Carlo simulation environment. Physical interdependencies between infrastructure systems (road, water supply, power) are explicitly represented. The framework is applied to Ibadan Metropolitan Area as the primary case study, with validation against documented hazard event consequences. Results demonstrate that multi-hazard risk to Ibadan's road network exceeds single-hazard estimates by 35 to 72 percent, depending on the correlation assumptions between flood, landslide, and heavy rainfall events. Critical road links with disproportionate network-level consequence of damage are identified, enabling prioritisation of resilience investment. The framework provides an original methodological contribution by integrating multi-hazard interaction modelling with infrastructure network analysis in a computationally tractable Monte Carlo environment calibrated for Nigerian conditions.

Keywords: multi-hazard risk, infrastructure assessment, Monte Carlo simulation, Ibadan, original framework