Climate Change and Coastal Floods: The Susceptibility of Coastal Areas of Nigeria

Abstract

The pressures caused by anthropogenic activities such as housing development and road construction, oil and gas exploration, economic development and demographic changes, have partly fuelled several environmental challenges faced in the coastal areas of Nigeria. One of these challenges is the flood events which have recently caused damage of properties and loss of lives in the areas. This study examines and predicts the susceptibility of the coastal region of Nigeria to flood hazard in a changing climate using geo-spatial techniques. Topographic maps and Moderate-resolution imaging spectroradiometer (MODIS) image of 2015 were processed, digitized, interpolated, classified and overlaid using the suitable algorithms. The MODIS imagery was classified into suitable land cover classes using the supervised maximum likelihood scheme. The 3D-analyst module was used to generate the Hydrological Digital Elevation Model (HDEM), Triangulated Irregular Network (TIN), and flood risk map of the study area. The flood risk map was classified into high, medium, low, and no risk zones. Results showed that, areas lying along the banks of Guinea coast are highly susceptible to flood hazards with the degree of susceptibility decreasing towards the North and eastern part of the area. These areas are classified as swamps (water-log) with low water retention which gives rise to high susceptibility of coastal flood hazards. The study discovered that the flood risk map can be used as an effective tool for precautionary measures, early warning systems, and consequently reduce the damages that could be caused by flood events.