Three-Dimensional Numerical Modelling of Tidal Current in Balikpapan Bay Using Delft 3D

Abstract

Abstract Balikpapan is one of the main port cities with residential areas, industry, trade, and vital objects scattered from north to south along the coast of Balikpapan Bay. This dense activity increases traffic in Balikpapan Bay. Thus, the hydrodynamic conditions in these waters are essential to be reviewed. The purpose of this research is to simulate hydrodynamics in Balikpapan Bay. The simulation results of the hydrodynamic model for sea-level elevation values are close to the conditions in the field, as indicated by the correlation coefficient 0.98, skill 0.99, and RMSE 0.15 m. The ocean current velocity verification includes the average correlation for x-direction and y-direction, up to 0.93, RMSE 0.05 m, and the percentage error of 6.7%. The significant current velocity is at low tide during spring tide with an average of 0.1 m/s and a maximum speed of 1.62 m/s. Temporally, the observation point at the mouth of Balikpapan Bay has the most significant Bed Shear Stress magnitude with an average of 0.05 N/m2. Spatially, the highest Bed Shear Stress magnitude is at the time of spring tide when it recedes towards the tide with an average Bed Shear Stress in the bay of 0.16 N/m2. The most dominant tidal components are M2 and S2, with a contribution value of 65.3%. The phase propagation from mouth to upstream of Balikpapan Bay for the M2 component in Balikpapan Bay is 10.5° (22.77 minutes) and 5.5° (11 minutes) for the S2 component.