Incorporating dynamics of land use and land cover changes into tsunami numerical modelling for future tsunamis in Banda Aceh

This study aims to investigate the tsunami exposure to current land use land cover (LULC) with the LULC predictions for the next 50 years, including the impact of sea-level rise (SLR) in Banda Aceh. This study began with a spatio-temporal dynamic analysis using LULC changes projection. Firstly, Markov Chain was used to simulate the changing trends in land use from 2011 to 2015. The changing trends were used to simulate land use predictions for 2015-2065 using Cellular Automata (CA). There were six main types of LULC classifications, i.e., ponds, built-up areas, mangroves, bare land, urban forests, and water areas. Furthermore, the map resulting from the land use simulation was used as the Manning Coefficients for tsunami simulation using the COMCOT model. The initial tsunami waves were generated based on the 2004 Indian Ocean Tsunami caused by 9.15 Mw earthquake. As a dynamic tsunami hazard approach, a sea-level rise of 0.35 m was considered for the next 50 years. The study results show the built-up area will be affected by the tsunami, about two-thirds of the city’s built area. Growth tends to occur in the southern part of the city outside the tsunami hazard zone. But there will also be the growth of built-up areas near the coast. Although much development is observed in the southern part of the city, the coastal area also needs attention because the sea level rise factor can exacerbate the impacts of tsunamis in the future