Urban Building Flood Vulnerability Assessment in Erbil City: A Geospatial and AHP-Based Approach

The frequency and intensity of flash floods increased substantially in recent years in the world which are the major risk for urban regions and environment. The objective of this comprehensive study is to assess the buildings vulnerable to flood hazards in Erbil city, Kurdistan region of Iraq using the integrated approaches of Geographic Information Systems (GIS), satellite remote sensing, and the Analytical Hierarchy Process (AHP). 14 flood-contributing parameters were used to map flood susceptible regions in the Erbil city. Rainfall, aspect, topographic wetness index (TWI), elevation, flow accumulation, lithology, soil data, normalized difference vegetation index (NDVI), normalized difference built-up index (NDBI), land use land cover (LULC), slope, stream power index (SPI), drainage density, and distance to roads were the factors that have been used to create flood susceptibility map (FSM). The FSM map showed considerable results with the accuracy of the 92.2%, using historical flood data to assess the accuracy. The results showed that 109 km2 (12.1%) of Erbil city area located in high and very high flood risk areas. Moreover, the outcome underscored startling results, showing that nearly half of buildings in Erbil city (47.6%) were located in high or very high flood risk areas. Additionally, the finding showed that 33853 (3.84%) and 69258 (7.85%) of population in Erbil city were located in very high and high risk flood zones, respectively. This study offers valuable insights for policy makers and urban planners, significantly contributing in monitoring urban environments, early warning systems, flood mitigation strategies and sustainable urban growth.