Flood forecasting based on geographical information system

Floodplain management is a recently new and applied method at the river engineering and is essential for prediction of flood hazards. On the other hand, for the purpose of managing and performing all river training practices, it is necessary to simulate complicated hydraulic behavior of the river in a more simple way. In this research, steady flow was simulated along similar to 4 km end of Zaremrood River (upstream of the Tajan River) and flood hazard extends derived using HEC-RAS/HEC-geoRAS. For simulating, first used HEC-geoRAS to define the river channel and extract cross sections from the TIN, then the results of pre-RAS within the steady flow data and the other required data imported to the HEC-RAS for process and ultimately provided 2-5-10-25-50-100-year inundation extends. The results indicate that hydraulic simulation by integrating HEC-RAS model GIS is effective for various kinds of floodplain managements and different scenarios of river training practices.