The Effect of Climate Change on Coastal Morphology Changes in Lhokseumawe City Area

Abstract The city of Lhokseumawe in Aceh is mostly located on the coast and is vulnerable to annual tidal waves, causing coastal settlements to sink. The rising sea levels in Indonesia, as observed by the IPCC using the TOPEX/POSEIDEN satellite, have reached 7 mm/year. A study was conducted to assess the impact of tidal waves exacerbated by sea level rise on changes in coastal morphology over 25 and 50 years. The study utilized the Delft3D numerical simulation method with various input data such as Topographic Data, bathymetry, tides, discharge, sediment, and waves. The results of the Delft3D modeling showed that erosion is slightly greater in the 25 and 50-year scenarios, with an average minimum erosion of about 12 m and a maximum erosion and retreat of about 18 m. However, in the 50-year scenario, there were points along the coast where sedimentation occurred, leading to the advancement of the coastline by about 36 m. These dynamic morphological changes in the coastal area of Lhokseumawe highlight the need for a coastal protection plan to address this vulnerability.