Impact of Storm Pabuk on a Monsoon Coral Beach: Bidong Island, Terengganu (Malaysia)

Abstract

Monsoon-influenced coasts commonly exhibit a clear seasonal pattern that may be undergoing variability associated with increased storm activity. A notable example is a rare tropical cyclone event in Malaysian waters in January 2019 that affected both marine and terrestrial environments in an exceptional context that diverged from seasonal Monsoon-influenced coastal geomorphic responses to waves. Storm Pabuk made landfall in the South China Sea, with its tail impacting Bidong Island, a coral reef island in Terengganu, Malaysia. Using data on coral coverage cover, aerial imagery obtained from an unmanned aerial vehicle (UAV) and numerical simulations of waves, this study investigates the shoreline changes caused by the cyclone, focusing on coral distribution and wave parameter modeling. The results reveal, unsurprisingly, that the coral reef beach was negatively affected, with a significant reduction in live coral cover. Interestingly, however, the shoreline saw an increase in beach sediment accumulation as well as shoreline length, highlighting both the negative erosion impacts of storms on corals but also their tendency to liberate new beach sediment. The effects of Storm Pabuk illustrate the importance of considering exceptional events in the study of Monsoon-influenced beach dynamics, especially in settings characterized by corals.