Flood Damage Estimate (Quantity), Using HEC-FDA Model. Case Study: The Neka River

Abstract

The cost of damages due to flooding depends on several factors. However, several methods, using different approaches, can be used to estimate flood damages. In this study, the residential area of Neka river, in the East of Mazandaran province (north of Iran), is considered. The most important part of the river basin is the Neka city that is located in intersection of the foothills and coastal zone (Caspian Sea). According to Francou-Rodier Formula, this basin is potentially at the high risk of flooding. During past decades, several floods have been observed, resulting in costly property damages and human casualties. Therefore, flood damages need to be estimated basing on different scenarios, to be able to propose engineering optimized options for flood controls and to better manage the subsequent crisis. In this research, using GIS models, HEC-RAS, and HEC-GEORAS software, hydraulic conditions of flood were simulated and flood prone areas were determined for different return periods. Based on the output of this step, using HEC-FDA, a risk analysis was performed and flood damages were estimated quantitatively. Finally, the Expected Annual Damage (EAD)was obtained.