Urban Flood Risk Assessment

Floods are a significant hydrological phenomenon, particularly in urban regions, where they become a natural disaster due to varied land uses, high population density, and intense flood events. Urban flooding management helps to assess flood extent and associated damages, enabling more-effective flood control strategies. This research evaluated urban flood risk in western Tehran, focusing on the western flood diversion channel. Flood vulnerability levels were estimated through flood zoning across different return periods, and risk levels were assessed using the FRTP method to estimate potential fatalities and injuries. The urban flood zoning results indicate that four critical axes are particularly sensitive to increases in floodwater depth and flow velocity. In these areas, floodwater frequently exceeds drainage capacity, making nearby passages highly prone to flooding. Flood risk zoning, based on land use, confirms that these four axes exhibit the highest risk levels, which closely correlate with expected annual damage (EAD) estimates. The findings underscore the urgent need for immediate flood management measures in these axes to effectively control water flow and minimize potential impacts.