Time-series analysis of satellite images for spatially evaluating long-term changes in Banda Aceh after the 2004 Indian Ocean Tsunami

The urban areas in the coastal region of Banda Aceh was destructively damaged in the 2004 Indian Ocean Tsunami. After the tsunami event, reconstruction and recovery has been extensively started in the affected areas. As the result of urban relocation, new residential areas were developed to provide housing for the affected people. Decades have passed since the tsunami, and such urban sprawl and concentration has occurred in Banda Aceh. Then, remotely sensed images would be useful to spatially evaluate such long-term changes of urban areas. In this study, we evaluate the spatial patterns in and around the affected areas in Band Aceh by time-series analysis of satellite images. The remote sensing images observed from 2000 to 2024 by the Landsat-5, -8, and -9 with the spatial resolution of 30 m were analysed, and spectral index such as Enhanced normalized difference impervious surfaces index (ENDISI) was calculated to characterize populated areas in the images. From the time-series analysis of the indices obtained from over 20 years observations, we discuss the spatial patterns of the changes of the populated areas.