Modeling of Sediment Transport Affecting the Coastline Changes due to Infrastructures in Batang - Central Java

The presence of newly-built infrastructures along the coast of Batang, Central Java, has inherent effects on coastal hydrodynamics and natural equilibrium of annual sediment transport near the coastline. Retreating coastline as a result of severe erosion continuously occurs at some locations in recent years. This study aims to calculate the sediment transport behaviour along the coast of Batang, Central Java, by considering the presence of infrastructures. Modeling was done by means of a commersially available software package MIKE21, especially the LITPACK module, developed by DHI Water and Environment, Denmark. The model shows that sediment drift parallel to the coastline occurs primarily within the distance of 300 meters from the coast. From 2010 to 2013, the general trend of sediment transport in the area is that there is a net sediment transport from the west to the east direction in the early months of the year, followed by a shorter period of transport in opposite direction (westward) for a few months. The inbalance of this sediment transport capacity is suspected to be responsible for the changes in coastline morphology in Batang.