Cohesive Sediment Simulation in Kanal Banjir Barat Using MuSed3D, Non-Orthogonal Boundary Fitted Sediment Transport Model

Abstract

Fine-grained cohesive sediments dominate sedimentation in the lowland area. In the Density Induced Current process, where seawater intrusion occurs, the fine-grained cohesive sediment will be easily flocculated by saltwater and settles rapidly. There are complex problems related to sedimentation in the rivers of Jakarta in the downstream area, which is influenced by tides and the dominance of cohesive sediment. Due to the complex process in the estuary, salinity intrusion will affect the settling velocity. And then, the flocculation process, the river’s geometry, will also affect sediment deposition. A proper model is needed to simulate the sedimentation in this area. This study aimed to investigate the distribution of cohesive sedimentation using 3D hydrodynamic and sediment transport model called MuSed 3D. This model will be applied to the Kanal Banjir Barat (KBB) river, Jakarta. The model result shows salinity values in the range of field observations for TSS and salinity. Salinity model present from 1 till 10 ppt and TSS present from 9,8 until 14,2 ppm. This study concludes that the dispersion of sediment cohesive on river and estuary affected by Density Induced Current also depends on salinity and TSS value.