Flooding is a natural occurrence in Bangladesh with devastating effects on significant areas, including Sylhet. This study aimed to summarize the flood susceptibility of different areas of Sylhet Sadar. This study is based on an approach that relies on free and open datasets rather than data obtained on the ground. NASA Earth Data was utilized to acquire satellite images of the study area (DEM at 30m resolution). The Surma River shapefile was obtained from humandata.org or HDX. Six individual maps were created, i.e., land cover, flow direction, precipitation, elevation, slope, and Topographic Wetness Index and each of the maps was then reclassified. Then the six reclassified maps were overlaid, summarized, and our final output came out as the Flood Susceptible Map of Sylhet Sadar. ArcGIS 10.8 version was used to create a flood-prone area, which was divided into five zones (very high, high, moderate, low, and very low). From this final flood susceptible map, we can identify the vulnerable zones or the flood-prone areas of the Sylhet Sadar and can take precautions or actions during the flood season. The study area’s low-lying plains are particularly susceptible to flash floods. The result shows that Kazir Gaon, Kurir Gaon, and Umairgaon are in a very high flood susceptible zone. South Surma is in a highly susceptible area. Khadimnagar is the least susceptible zone. This research can aid in the development of appropriate flood management strategies and policies to minimize the risk of future flood-related damages and losses in the region.
Keywords: Flood Susceptibility, Sylhet Sadar, GIS, Satellite Image, Surma River, Vulnerable.