Coastal Erosion Management by Implementing Concept of Building with Nature (BwN) in Demak Regency, Central Java, Indonesia

Abstract

Coastal erosion that occurring in the north coast of Java, led to significant coastline erosion. One of the areas that run into the coastline erosion is Demak Regency. To overcome the problem, the concept of Building with Nature (BwN) is proposed. This concept uses the media from nature to reduce the wave energy and being sediment trap. BwN has applied in Demak Regency, exactly in Sayung village since 2013. According to the evaluation, the BwN was able to capture sediment of 0.4 cm/year. The amount of sediment is expected to be increased by adding the number of BwN and change the pattern of BwN. To determine the amount of increased sediment, a model using the DELFT3D software is utilized. The data used in the model is based on field measurement data in 2016. BwN in the model is defined as thin dam. The results show that the average amount of sediment around BwN after adding two BwN in front of the existing BwN increase to 0,6 cm/year. This solution is expected to help the faster shoreline restoration in Demak coast.