Flash flood hazard areas assessment in Bandar Negeri Suoh (BNS) region using an index based approaches and analytical hierarchy process

Abstract

Flash flood led to high levels of water in the urban areas, causing many problems such as bridge collapse, building damage and the victim died. It is impossible to avoid risks of floods or prevent their occurrence, however, it is plausible to work on the reduction of their effects and to reduce the losses which they may cause. The objective of this paper is to generate a flash flood map in Suoh region, using satellite images, UAVs images and GIS tools. Analytical Hierarchical Process is used to determine the relative impact weight of flood causative factors to get a composite Flood Hazard Index (FHI). The causative factors in this study are flow accumulation (F), rainfall intensity (I), geology (G), land use (U), slope (S), and elevation (E). The presented methodology has been applied to an area in Suoh region, where recurring flood events have appeared. Initially, FIGUSE method resulted in an FHI and a corresponding flood map. A sensitivity analysis on the parameter’s values revealed some interesting information on the relative importance of each criterion, presented and commented in the discussion section.