Floodplain Mapping Using Hydraulic Simulation Model in GIS

In this research, a methodology was applied to integrate hydraulic simulation model, HEC-RAS and GIS analysis for delineation of flood extents and depths within a selected reach of Zaremroud River in Iran. Floodplain modeling is a recently new and applied method in river engineering discipline and is essential for prediction of flood hazards. It is necessary to simulate complicated hydraulic behavior of the river in a more simple way, for the purpose of managing and performing all river training practices. In this research, steady flow was simulated along 3 km end of Zaremroud River, upstream of the Tajan River in North of Iran. Floodplain zonation maps were derived using integrating of HEC-RAS and GIS analysis. Delineation of flood extents and depths within the floodplain were conducted in different return periods. Critical flooding area along the river was distinguished based on the grid layer of flood depths. The results indicated that hydraulic simulation by integrating with GIS analysis could be effective for various kinds of floodplain management and different scenarios for river training practices and flood mitigation planning.