Flood Hazard Mapping in Baolan, Tolitoli District, Central Sulawesi

Abstract

Floods has been the type of hazard that often hits the capital of Tolitoli Regency, Central Sulawesi Province,
namely Baolan District. The flood in 2017 was the worst incident that had ever occurred in Baolan District; it was
recorded that the water level (flood) reached 4 meters, 15 houses were badly damaged and lost by the flood currents.
This research was conducted in Baolan District from May to August 2021. The tools and materials used in this study
were: a laptop, ArcGis 10.4 software, and secondary data (rainfall data, Digital Elevation Model — DEM data, soil type
maps, and RBI maps at 1:50,000 scale). The research method used is descriptive quantitative with a spatial approach
using saturated sampling rules obtained from the entire population. The purpose of this study was to determine the
level and distribution of flood hazard areas in Baolan District. The results of the analysis show that Baolan District has
the narrowest (small) level of flood hazard, namely very low class with an area of only 263.261 ha or 0.7% of the total
area of Baolan District. Low class with an area of 31460,417 ha or 79.8% and is the class/level of the widest (large)
flood hazard. High and very high class respectively have an area of 6713.534 ha or 17.0% and 975.914 ha or 2.2% of
the total area of Baolan District. In general, the areas that have very high to high grades are located in the southern,
central, and western parts of the research area, including Kelurahan/Desa Tambun, Baru, Nalu, and Leleannono.