Understanding the effect of reclamation in Jakarta Bay using a three-dimensional hydrodynamic simulation approach

Abstract

The research investigates the possible effects on the reclamation project in Jakarta Bay which is located in the north of Jakarta, the capital city of Indonesia. The concept of rearranging the north Jakarta coast includes the concept of reclamation 17 islands. The impact of the reclamation project may increase the sedimentation in the river mouth and may degrade the ecosystem and environment quality its vicinity. The bay is a shallow water area with an average depth of 15m. In the research, sediment distribution is simulated using several parameters: surface water level, water depth, precipitation rate, and river discharge from five rivers which feed the sediment and fresh water to the bay. The simulation is developed in order to examine the condition of the bay before and after the reclamation project. The research attempts to reveal the inter-correlation between the tidal current, river discharge, and the cohesive sediment in the bay. The hydrodynamics simulation before the reclamation project was run for 31 days in the month of January (wet season) and September (dry season) in the year of 2011. The simulation after the reclamation project was run for 29 days in February (wet season) and May (dry season) 2016. Based on the research, the movement of sediments is dominantly influenced by the tidal current instead of the precipitation and river discharge. The research also revealed a high turbidity level near the river mouth particularly in Cengkareng River. The erosion and sedimentation rate tend to the increase the loads from the catchment areas. However at the same time, the erosion in other areas is increased as a result of the development on the coast of Jakarta Bay.