Influence of Grain Size on the Sediment Budget for Nourished Sand Bars in Hoi-An Area

The phenomenon of deposition and erosion on Hoi An beach in recent years has been the research topic of many organizations and researchers. Many solutions have been proposed to mitigate the erosion and one of the selected solutions for coastal protection is the nourished sand bars. This approach has the benefit of preserving the natural scenery of the tourist beach, as a certain amount of sand needs to be added each year to maintain shore protection against the waves and winds prevalent in the area. The size of the sand grains plays a critical role in the efficacy of the sand trap. This research employs the Telemac numerical model, which integrates problem-solving with hydrodynamics and coastal wave calculations, to quantitatively analyze the impact of sand grain size on the time-average expected sand deposition under various scenarios. The simulation results indicate an inverse correlation between the average diameter of sand grain size and the required amount of additional sand, as well as the effect of extreme weather conditions such as increased waves and wind on the amount of sand needed for nourished sand bars.