Hydrodynamic Pattern of the Tando Bulong Strait, Semporna, Sabah, Malaysia
Ejria Saleh, Jasica Chua and Muhammad Rashid Abdul Rahim
Borneo Marine Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, MALAYSIA;
Abstract
Semporna is one of the most significant areas in the Malaysian Coral Triangle. This area is known as Semporna Priority Conservation Area (SPCA) and the first Marine Spatial Plan in Malaysia. The shallow water areas within its islands are identified for mariculture activities, fishing sites and tourists destination. One part of the area is Tando Bulong Strait located between Semporna and Bum Bum Island. The excellent natural environment and high marine biodiversity are related to water circulation. The objectives of this study are to determine water current pattern and wave impacts along the strait using numerical modeling. Field surveys of bathymetry, deployment of two Acoustic Doppler Current Profilers (ADCP) for water level and current measurements were done from 1 to 30 August 2017. During this field trip, assessment of current coastal community activities along the strait was also carried out. The field data (water current and water level) were needed for validation and verification of the Delft3D modelling software. The waves, current speed, and direction were analysed and presented on different tidal cycles and seasonal monsoon. Results indicate that tidal cycles and seasonal monsoon play a major role in water exchange of the Strait. The current speed along the coastline is about 0.3 m/s but increase up to 0.37 m/s along the Strait. The model predicted that flood tide current speed during the northeast monsoon flows southwards and increase between 0.6 m/s and 1 m/s at the middle of the Strait south. The wave height during this monsoon is approximately 0.65 m in the north and decreases down to 0.3 m inside the strait. The water circulation is important for the mariculture (seaweed farming), fish cages and marine pollution management. The findings will hopefully lead to a better understanding of the dynamic of the Tando Bulong Strait and improve the future prediction state of the Semporna area.
Keywords: Current pattern, waves, monsoon, Tando Bulong Strait, Semporna
Topic: Coastal and Ocean Dynamics