Cut and fill analysis of Palu Bay seabed topography pre and post-tsunami

Palu Bay is an earthquake-prone area, in September 2018 tectonic earthquake occurred in Donggala District, Central Sulawesi, which caused tsunami due to underwater landslides. One of the impacts caused by the tsunami was changes in bathymetry. In tsunami post-disaster reconstruction, further studies regarding seafloor topography information of affected areas are needed. This study examines and analyzes the underwater landslide in Wani, Palu Bay 2018 before and after the underwater landslide using bathymetry, and coastline data to determine cut and fill volume. The analysis was conducted on the three components: Contouring, slope/gradient, and volumetric (cut and fill). The contouring results show significant depth changes at the 200-meter contour on Tanjung Labuan, Palu. The volume calculation from two surfaces shows 59,512,720.790 m³ cut and 12,466,252.630 m³ fills in the landslide area.