Impact Of Wave Dynamics On The Coast Of Ghana

ABSTRACT Wave and wind dynamics are important in the estimation of beach erosion rates and sediment transport modelling. They are also important in modelling sea fatigue, oil spill transport and planning of coastal and marine activities. This work sought to quantify the magnitude of wave and wind parameters along the coast of Ghana as well as identify how these parameters varied across the year. A nine years wave and wind data from the National Oceanic and Atmospheric Administration (NOAA) global wave model and data from a Wave Rider Buoy were analysed for this purpose. Wave data analyses were based on long term and short term methods. Potential sediment transport rates were also calculated using the Soulsby-Van Rijn sediment transport equation. From the results, mean significant wave height was 1.39 m, mean period was 10.91 s and mean wind speed was 4.65 ms-1 . The results also revealed monthly trend of wave heights where wave heights increased gradually from January (1.00 m), the beginning of the year to a peak in August (1.73 m) and then began to decrease to a low in December (1.10 m). Wave periods also exhibited an almost similar trend but the highest wave period occurred in May (11.85 s). Wind speeds showed similar monthly variability and had the highest in July (5.61 ms-1 ). Wave directions were mainly in the South (S) and South-South-West (SSW) direction with those in the SSW direction forming majority. Sediment volume transport were also determined where crosshore transports, 2.25E+08 m3 y -1 , were found to be higher than longshore transports1.82E+08 m3 y -1 (E+08= ×10^8; m3 y -1 = metre cube per year). The outcomes of this study are very relevant as it will aid in policy making for the monitoring and protection of the coastal environment and; serve as a guide for the construction of coastal and offshore structures.