Application of HEC-HMS Model for Prioritization of Flooding Potential in Upper Karaj Dam Catchment

Flood is one of the complex and destructive natural phenomena that cause heavy damages every year. The factors of river routing and spatial location of sub-catchments are effective on catchment outlet flood. Hence for performing of flood control measures in upstream parts of great catchments، their effect on catchment flood must be investigated and sub-catchments were prioritized with respect to the contribution of these factors to outlet flood. Karaj Dam catchment was selected due to flooding for this study. In this research، geographic information system (GIS) and HEC-HMS hydrologic model were jointly used to investigate the contribution of each sub-catchment to whole catchment outlet flood based on SCS method. For this purpose، flooding potential of sub-catchments was prioritized using unit flood response approach in HEC-HMS. The results show that Tekyesepahsalar sub-catchment has the most contribution to whole catchment flood and Velayatrud sub-catchment has the least contribution to flooding potential.