Marine macro debris transport based on hydrodynamic model before and after reclamation in Jakarta Bay, Indonesia

Jakarta Bay as an area with the densest population in Indonesia is one of the highest contaminated waters in the world including pollution of debris. Reclamation activities in Jakarta Bay will change the water conditions and will also affect the distribution of debris at sea. This study was conducted to determine the movement of the macro debris before and after bay reclamation in Jakarta Bay. The method used is a simulation model using the hydrodynamic and particle trajectory models. The hydrodynamic model used data on wind, tides, bathymetry, and shoreline, while the trajectory model used data on macro debris, debris weight, and debris flux. Hydrodynamics simulations indicate that the reclamation does not change surface current patterns significantly, but resulting in a decrease in flow velocity from around ± 0.002 m/s to 0.02 m/s at some point. The trajectory of debris particles indicates that after reclamation, macro debris tends to accumulate in the eastern region of Jakarta Bay during the rainy season (January) as there are anticlockwise eddy currents. However, debris tend to accumulate in both the western and eastern regions during the dry season (July) due to a clockwise eddy current in the eastern part of Jakarta Bay.