Quantification of the shoreline evolution of an open beach between coastal defenses
The Ghanaian coastline is exposed to low to medium energy waves generating strong nearshore currents that cause erosion and pose risks to coastal dwellers. Harbours, dams and coastal defenses along this coastline disturb its natural equilibrium and causes extreme erosion up to 17 m/yr. The morphological response of micro-tidal beach to waves and erosion controls is studied in Dzita, a coastal community in Ghana using video system and unmanned aerial photography. The results reveal significant sediment lost from the beach through cross-shore wave energy flux. The study finds low sediment transport in the longshore direction compared to the cross-shore direction possibly due to the presence of several groynes and strong rip currents. Predominant erosion occurs between August and September. This beach may continue to erode and maybe rapidly in the future because it has to be the source of sediment to nearby beaches and is also unprotected.