Pages: 27-36

Abstract

Awareness of flood zone is widely used in studies of river management, safety of beaches and environmental issues. Given the importance of this issue, determining flood zones with different return periods are necessary to identify high risk areas for flood insurance, create user mandatory limits in high risk areas, avoid risk of floods, organize and optimize rivers and determine available facilities in adjacent of rivers. The research estimates flood zones and economic losses caused by Karun River in Khuzestan province by integrating hydraulic model of HEC-RAS using GIS software through HEC-GeoRAS annexation. To determine flood zone, there is firstly created geometry file of the studied river in GIS environment using HEC-GeoRAS side-program. Then it is transmitted to HEC-RAS model and GIS of extending flood zone in return periods of 25, 50, 100, and 200 years will be evaluated after calculating the required parameters and sending results to the environment. In this method, it is necessary to have full topographic data of the region and hydraulic conditions along the river, in order to calculate flood zoning. Using the data, there have been determined flood zones for different levels in different return periods. . On the return periods of 100, and 200years across the distance of 2500 meters from the beginning of the area for 800 meters length and across the distance of 5380 meters from the beginning of the area for 1250meters length off the right bank, and the lengths of 2500 meters to 3300 meters, and the lengths of 7940 meters to 8730 meters off the left bank of the river, the water advances in to the farms, and residential areas, and, according to the findings, the torrent flood over higher return periods