Assessment of Flood Damage on Humans, Infrastructure, and Agriculture in the Ghamsar Watershed Using HEC-FIA Software

Abstract

Floods, as one of the most catastrophic events among the wide variety of natural hazards, impose considerable damage to humans, infrastructure, and industrial and agricultural sites. To identify flooding-prone areas and having knowledge on occurrence probability or return period of flood events can be promising for planning and alleviation of damage caused by this natural phenomenon. This paper seeks to assess flood risk in the Ghamsar watershed, so cross sections were plotted using a digital elevation model (DEM) and stream geometric data in the Hydrologic Engineering Center’s Geospatial Processing Data for River Analysis System (HEC-GeoRAS). The output was transferred to the Hydrologic Engineering Center’s River Analysis System (HEC-RAS) and flooded area with different return periods with data created by an unstable simulation in the Ghamsar River. These results together with field data collected from region were entered into the Hydrologic Engineering Center’s Flood Impact Analysis (HEC-FIA) software and flood damage was estimated. Results showed that 3.23 ha of cultivated lands will be subject to damage ($378,358.99). As for infrastructure, a number of 36 buildings units surrounding the river will be subject to floods and at the same time the flood causes some causalities. The results of this research can be used in development plans and the construction sector in order to alleviate damage caused by floods in urban and rural areas and floodplains and for river bank conservation.