Assessment of Social Vulnerability for Efficient Management of Urban Pluvial Flooding in the Lagos Metropolis of Nigeria

Flooding of pluvial origin has been pervasive in the Lagos area of Nigeria, and threatens significant human populations and urban assets, resulting in large scale economic losses. Unfortunately, investigating especially the human impacts of this hazard is often hampered by the dearth of quality datasets. This study was designed to construct indices of social vulnerability (SocVI) to pluvial urban flooding in the Lagos areas, using available demographic datasets. This will facilitate knowledge transfer and policy development towards mitigating the human impacts of flooding which is a crucial concern in environmental studies, earth sciences, disaster prevention and flood risk management research. Social vulnerability was conceptualised in terms of exposure, susceptibility and lack of coping capacity, whilst nine indicators were normalised, aggregated and ranked using combined UNDP's Human Development Index and Patnaik and Narayana methodologies. Results reveal high indices of social vulnerability to pluvial flooding in three local government areas of Lagos - Alimoso, Agege and Kosofe. The study also identifies patterns of vulnerability based on individual social components. Gender variation, socio-economic status, and family structure were found to have significant impacts on the overall index. In addressing the challenges of pluvial urban flooding in Lagos, this study recommends prioritizing resources and intervention, especially in relation to building effective coping capacity in those areas that indicate higher social vulnerabilities to the hazard. This study, by constructing new SocVI, has demonstrated the potential in freely available datasets to investigate social vulnerability for Lagos.