Calculate the Flood Hydrograph for Karun Basin, Iran

Abstract

In structural and un-structural methods of flood control, it is necessary to predict flood potential in the water closed basin. In this research, the purpose is simulating flood in the basin of SCS hydrologic model of HEC-HMS and comparing with mod-Clark method by doing geographic information system (GIS) in Golestan wa tershed was performed. Finding a model that can properly predict floods at large and sensitive basins like Karun the largest river in Iran is necessary. Because of being prone to flooding, identifying areas prone to flood and flood production levels according to physical characteristics of the catchment is essential. In this research, hydrologic modeling was performed on the Karun Basin, and tried to estima te flood hydrograph through both lumped and distributed mathematical models to analyze how close they are in reality from Karun basin to Shalou Bridge. In this method by topography maps created basin DEM in the environment of (GIS) software. by used of crea ted DEM, canals and sub-basin maps mine and with mixing soil hydraulic group maps it make ground user and data of previous moisture in (GIS) environment of C (number curve) map of Karun under watershed then it measure and credit with raining data and observation running of wa tershed fixing in HEC-HMS model and at the end it compare by mod-clark method with in software environment of (GIS) geographic information system. Formation of precipitation and surface flow after rainfall and formation of hydrograph has been studied using both SCS lumped model and Mod-Clark (modified Clark) distributed model and it is identified the distributed model results are closer to the recorded hydrograph of the basin.