Assessment on the efficiency of embankment dams in flood hazard decrease in Hajighoshan watershed

Flood has caused financial and vital damages in the Hajighoshan watershed in recent decade. In this study، we investigated the efficiency of flood control structures in decrease of flood hazard and their effects in the downstream flow regime. First، a rainfall-runoff model has presented by using HEC-HMS model. The rainfall- runoff model was presented and optimized by using 5 past flood events and then was validated with 4 another flood events. The dams were simulated by using Elevation-Area method in the validated rainfall-runoff model. The results showed that The efficiency of flood control dams in decreasing of flood hazard dependents on their location، reservoir volume and the surface of watershed or sub-basin which it controlled its runoff.