Drowning in the Sea: A Digital Shoreline Analysis of Coastline Changes in Ilaje, Nigeria

Abstract

This study investigates shoreline changes to identify the affected communities, quantify the change rate, and explain the underlying factors that drive the changes. The study analyzed shoreline movements utilizing multi-date, high-definition satellite imagery from Google Earth Pro, which was derived from various sources including Landsat, Copernicus, Maxar Technologies, and TerraMetrics for the years 1984, 2010, and 2023. The DSAS plug-ing in ArcGIS 10.7.1, 1,582 transects were generated at 1000-metre intervals. The End Point Rates (EPR) and Net Shoreline Movement (NSM) were calculated for the three periods. The result revealed an NSM of −56.37 m/yr, indicating the dominance of erosion along the coast, with more than 70% of the coastline witnessing erosion. Kusemeta, Epene, and Awoye communities highlight the severity of the shoreline changes with values exceeding −400 m/yr, the cause of which has been linked to the development on the adjacent coast of Lagos and Lekki. The EPR shows a variation from −23.38 m/yr to 13.73 m/yr, further highlighting the erosion process and sediment deposition, respectively, though the latter dominates. The study underscores the severity of the shoreline recession on the Ilaje coast and recommends that future coastal development and erosion controls consider the broader impact on the adjoining coast.