Modelling the variability of Fuveme beach in the lower Volta Delta, Ghana

Abstract

Issues of coastal erosion have been on the rise globally due to climate change and anthropogenic activities such as the construction of dams, harbours and coastal defences. According to multiple reports, the Fuveme coastline in eastern Ghana, West Africa, has been experiencing regular flooding and erosion since the mid-1880s. The intense erosion and flooding at Fuveme have been attributed to reduced fluvial sediment transport to the area. Recently, the sea breached a nearshore sandbar on the coast creating a ‘new estuary’ where tidal waves now move water and sediment between the sea and the estuary. This seems to be exacerbating erosion and flooding. The aim of this research was to assess the geomorphic variabilities surrounding the ‘new estuary’. Hydrodynamic conditions (wave heights, tides and currents) off the coast of Fuveme were retrieved from ERA 5 website and aerial photographs of the beach were collected from October 2021 to October 2022. Sediment dynamics were assessed using MIKE 21 software to predict the trend of sediment movement along the coast of Fuveme. The results showed significant sediment exchange with -18.02 ± 0.25 m/yr shoreline erosion, 126, 979 m3 and -35,359 m3 sediment volume changes over the period as a consequence of the overtopping/flooding and the hydrodynamic conditions that are resident on the Fuveme Beach. The magnitude and direction of sediment total load were simulated with results showing higher sediment rates on the eastern stretch of the area. At the end of the study, wave action was found to be the principal hydrodynamic condition that affected the coast of Fuveme. Further studies are recommended to ensure a deeper understanding of the area’s beach dynamics and for better coastal management purposes in the Volta Delta as a whole.