The Hydrodynamics Simulation of Tidal Current in Balikpapan Bay

Balikpapan is located on the east coast of Kalimantan Island, directly adjacent to the Makassar Straits, and serves as a shipping lane and port city. The hydrodynamic conditions in Balikpapan Bay are essential to know because it dramatically influences the processes that occur. This study will simulate the hydrodynamic pattern of Balikpapan Bay using the Delft3D numerical model by analyzing changes in the depth-averaged velocity and analysis related to the bottom current. 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 0.93, and RMSE 0,16 m. The most dominant tidal components are M2 and S2, with a contribution value of 65.3%. In the spring tide conditions, the highest elevation value was 1.55 m, the lowest elevation was -1.42 m, so the tidal range is about 2.99 m. In the neap tide conditions, the highest elevation value was 0.62 m, the lowest elevation was - 0,57 m, so the tidal range was around 1.19 m. The highest current velocity magnitude is at a point B with a value of 0.31 m/s and occurs when flood tide during spring tide. A significant change in the tide when the ebb tide towards high tide at point C, which increases by 680%. Meanwhile, during the neap tide, significant changes occur in ebb tide conditions towards high tide at point B, which increases 689%. Significant changes when spring tide increases by 250% from point C to point D at ebb tide conditions. Meanwhile, significant changes occur from point B to point C at low tide during the neap tide, increasing the magnitude by 338%.