Variation of beach sand in relation to littoral drift direction along the Kuala Terengganu coast

Abstract

A knowledge oflong shore variation in beach sediment and littoral drift direction is important for making decisions in coastal zone management and coastal engineering, especially in the construction of ports and breakwaters. This paper discusses a systematic analysis of the beach grain size variation along the north-western coast of Kuala Terengganu by applying a time series approach. The study area is located close to the city of Kuala Terengganu, extending from the beach at Tanjung Gelang to Kuala Ibai. The beach sediments in the study area are exclusively sandy with median diameter between coarse and fine grained sand. The median grain size, as well as sorting and skewness values show a spatial and temporal variation throughout the entire study area The median grain-size generally decreases along the direction of the littoral drift with increasing distance from the sediment source. The beaches' morphologies vary throughout the area, with finer beach sediment causing a more gentle foreshore due to less erosion. The study shows that sediment grain-size gradation can be used as an indicator of net littoral drift direction.