Beach erosion: a study of cross-shore particle size chaaracteristics and profile evolution along the Ghanaian coastline

Abstract

The coastline characterized by the geologic nature of the land and the dynamic power of the sea, is constantly changing as a result of many factors both natural and manmade. The phenomenon is highly influenced by winds waves, currents, and tides that transport beach sediments up and down the profile. However, source material characteristics tend to complicate this mechanism in profile evolution. Beach profiling and particle size analysis coupled with wind wave analysis were used to analyse beach moiphology of five beaches along the Ghanaian coastline within two seasons, (dry and wet seasons) to establish the seasonal variations in beach state and profile evolution that impact on erosion in general along coastal erosion structures. Findings showed all beaches were moderately sorted with sorting values ranging from 1.70 to 1.85 in both seasons. Tt was also found out that the dominant grain size along all study sites were the 250 pm in dry season and 500 pm in wet season. The beaches were made up of fine to medium grains. percolation was minimal due to the dominant grain size and led to increased wave runoff which caused erosion of the beach face. Beaches showed seasonal variability in volume and width. The beaches experienced stomy conditions in the wet season and as a result, erosion was strong during the wet season.