摘要：This study aims to map the distribution of floods that occurred due to the overflow of the Amasing Kali River on Bacan Island, South Halmahera. The magnitude of the flood as an input in the Watershed (DAS) system was analyzed using the Nakayasu unit synthetic hydrograph (HSS) method, while the morphometric characteristics of the watershed were analyzed by extracting digital elevation model data (Digital Elevation Model, DEM) using a Geographic Information System (GIS) application. The simulation of flood distribution with return periods of 2, 5, 10 and 25 years was carried out by applying the HecRAS 2D application. The mapping of the analysis and simulation results of this study shows that the potential flood-affected areas are on the north and south sides of Amasing Kali village with inundation heights varying between 0.50 m – 1.50 m.
