Simulation Model of Lembasada Coastline Changes in Supporting Post Tsunami 2018 Tourism Beaches

This research aims to determine the coastal changes that occurred on Lembasada beach during the 25 years after the construction of beach protection and filling of beach sand and to determine the extent of abrasion that occurred and to obtain alternative abrasion management at the research location in Supporting Post-Tsunami Tourism Beaches 2018. This research uses the method overlapping (Overlay) Landsat satellite images for 2012 and 2022 on ArcGIS software as well as predictions of shoreline changes for 2030 using the Generalized Model for Simulating Shoreline Change (GENESIS) software. The results of forecasting changes in coastlines at the entire study location for 25 years show that there is erosion and accretion with the rate of change in erosion ranging from 1 to 2 meters per year. Analysis carried out in Lembasada Village shows that there are changes that are classified as moderate to large, there is no protection on the south side or beach protection on the north side which has been secured with a breakwater. The results showed that the area of abrasion on Lembasada Beach was 2,071.71 m², based on simulation results, the breakwater building is the right beach building to overcome the problem of abrasion at the research location.