Assessment and zonation of flood susceptibility in Sylhet Division, Bangladesh using GIS and Analytic Hierarchy Process (AHP)

This study integrates the Analytical Hierarchy Process (AHP) with Geographic Information System (GIS) techniques to create a detailed flood susceptibility map for the Sylhet division in northern Bangladesh. The primary goal of the paper was to classify the region into distinct flood susceptibility zones, thus providing valuable insights for improving flood risk management, mitigation, and preparedness strategies on a localised scale. The study evaluates flood risk through 12 influencing parameters, including elevation, slope, precipitation, drainage density, proximity to roads and rivers, vegetation, and soil type.

The results show that approximately 35.27% of the Sylhet division, particularly the northern regions and the low-lying Haor basin, fall into the "high" flood susceptibility categories. These areas are highly vulnerable due to their flat topography, proximity to major rivers, and inadequate drainage systems. In contrast, the southern and southwestern areas, accounting for around 7.45% of the region, exhibit "low" flood susceptibility, benefiting from higher elevations and better natural drainage.