Beach morphodynamics and evolution of monsoon-dominated coasts in Kuala Terengganu, Malaysia: Perspectives for integrated management

Abstract Coastal defence structures have a strong influence on the configuration of shorelines. Artificial structures can influence the wave regime, hydrodynamic circulation and sediment transport, thus reducing the ability of a shoreline to respond to natural forcing factors (such as the monsoonal regime) which also fragment the coastal space. In the studied area on the Kuala Terengganu coast of Malaysia, a new 1-km airport runway extension was constructed with a tarmac structure jutting out into the sea. This extension structure has a groyne-shaped geometry that has consequently altered the shoreline, hydrodynamics and sediment transport patterns on the adjoining coast. This recently transformed environment is investigated using the Digital Shoreline Analysis System (DSAS) and Mike programs. The objective of this article is to describe the various coastal morphodynamic situations, as well as discuss the sustainable erosion mitigation strategies that are available, by involving local stakeholders within the coastal management system itself. The lessons learnt from previous management failures show that addressing the concerns, views and opinions of local stakeholders is pivotal, and must be taken into consideration by consulting them during the early stages of the planning process and beyond. The study then sets out a proposed solution to the issues at stake, based on a combination of detached breakwaters and beach nourishments within the critically eroded areas. There is indeed a direct need for more coastal defence structures in the studied area due to the ever-increasing coastal erosion, especially in the northern sector. In fact, although a series of revetments/ripraps have been built in the past to protect the beaches from erosion, these artificial structures have proved to be quite ineffective in mitigating the erosion problem at the sites in question.