The Effects of Seasonal Monsoon and Coastal Defence Structures on Littoral Transport Off the Terengganu Coast (Malaysia)

Maintaining natural sandy shoreline behaviour following human intervention is quite challenging. Anthropogenic activities have disrupted sediment transport, leading to insufficient sediment supply, causing a loss of natural beach characteristics. The Terengganu coastline, located on the east coast of Peninsular Malaysia, directly faces the South China Sea, historically featured pristine sandy beaches. Recent observations of beach conditions showed that some of the Terengganu shoreline has been exposed to downdrift erosion, which has increased. There has been increased pressure to find efficient mitigation solutions. The Digital Shoreline Analysis System (DSAS) was used to study the rate of change of the shoreline. Meanwhile, beach profile data and sediment sizes were used to evaluate the beach status on a bi-monthly basis following the seasonal monsoon. A MIKE 21 model was used to understand the relationship between sea-land interactions and responses. The result demonstrates that historical shoreline evolution confirmed the downdrift erosion due to insufficient sediment supply from the updrift beaches. Contrarily, seasonal changes from beach profile, sediment size, and wave modelling evidenced the topographical, grain size, and wave changes, respectively distracts the littoral transport in the study areas. This article intends to discover the relationship between the changes in littoral transport concerning the anthropogenic and natural effects on the Terengganu coastline, especially in Kuala Nerus and Dungun, Malaysia.