Urban expansion and enhanced flood risk in Africa: The example of Lagos

ABSTRACT The world is increasingly characterised by uncertainty, complexity and rapid change while vulnerability to potential disasters is equally increasing. The situation is more dire in countries where governments are unable to manage land use and development in rapidly growing towns and cities. Lagos, a major city in Nigeria, is notorious for flooding, owing to its being lowland, and this is compounded by inadequate planning and uncoordinated physical development. A systematic study of urban expansion in Lagos was done using Landsat ETM, OLI and Google Earth imageries for 2000, 2013 and 2019 to analyse land use and land cover change, and pattern of encroachment of physical development into vegetation cover and flood plains in Lagos. The comparison of the three Land Use Land Cover Change (LU/LC) schemes, indicates that built-up areas accounted for about 50.0% of land use in Lagos in 2019. The increase is almost thrice the extent recorded in the year 2000. As the pace of growth quickens, new structures deplete vegetation and fuels lateral expansion into marginal land. Adherence to land use planning regulation, vertical expansion and flood-plain-buy-back were recommended as strategies to mitigate flood risk.