Recent retreat and flood dominant areas along the muddy Mahin coastline of Ilaje, Nigeria

Abstract

The rates of retreat around the world, especially in low-lying coastal areas, have been pernicious in recent years. For some time, coastal retrogradation may follow a historically observed trend. However, a slight increase in ocean and climate indices, including sea level, temperature, and precipitation, can cause significant modification in the littoral profile. This study reports the recent changes and possible future threats along the Mahin mud coastline, Ilaje Local Government Area of Nigeria, West Africa. This study aims to understand the present evolution of the coastal area in order to manage the environmental and human risks in the future. Satellite images and Digital Elevation Model (DEM) map in the Geographic Information System (GIS) were used to evaluate the retreat rates of 20 years and delineate flooded coastal areas under some sea level rise (SLR) scenarios. Results showed that the areas of retreat dominance in recent years were once mostly accreting. In comparison, some areas that were receding have gained more land. Still, the rates of retreat in other areas have further intensified. Based on the DEM map analysis results, coastal flooding may very soon extend several kilometers inland, covering large areas of the southeastern sector. Therefore, this observation is essential to ensuring appropriate coastal protection plans are put in place.