Studi Transportasi Sedimen pada Alur Pelayaran di Muara Sungai Donan, Cilacap-Jawa Tengah

Abstract

The purpose of this research is to model sediment deposition at a site on the waterway of the Donan River Estuary, Cilacap-Central Java. The research carried out in this thesis, aims to create a model to represent the hydrodynamics and sediment transport patterns prevalent at the site, using MIKE 21 Flow Model (FM) developed by DHI. The model is calibrated using the available data. The model is built using two scenarios, where the first scenario using existing bathymetry and the second one using the data after maintenance dredging -17 m LWS for big vessel in Donan River. Water depths and sediment patterns should be considered by the vessels that will use the navigation channel at a river mouth. Based on field observation and simulation results,the calibration of tidal has an 3.53% correlation while the river current correlation has 15.46%. Concentration and sedimentation rate will be analysis to bed level change and sludge of sedimentation volume with cross section calculation. Sedimentation rate from simulation along one year is 0 - 0.0006 m/day so 0.219 m/year or 21.9 cm/year. Where, the result of sediment deposition using first scenario is 227,912.00 m3/year and second scenario is 225,216.60 m3/year with observation data average/year that is 217,321.756 m3/year, so result of the model equal to the actual situation in field data. It can be concluded that maintenance dredging plan in location every five year is needed to support draft full vessels available capacity 115,000 DWT with water depth – 17 m LWS and waterway width 130 m.