Golestan Dam Operation in Flood Conditions to Minimize Flood Damages in Downstream of Dam

The aim of this study is investigation the application of operation scenarios on Golestan dam to reduce the inundated area and the flood damages at downstream of dam. So considering confidence interval, the inflow hydrographs for Golestan dam were calculated for 4 return periods (25, 50, 100, 200 year). Then these hydrographs were routed through Puls method in order to obtain the outflow hydrographs passing through dam spillway. Also, the integrated of Geographical Information System (GIS) and the HEC-RAS hydraulic model were used to produce a flood map for different floods. Finally, the damage to land around the river was estimated in each scenario. The results showed that assigning a flood control volumes in Golestan dam is effective only for floods whit peak discharge up to 2000 m3/s. And as the flood peak discharge increases, the effect of dam on flood controlling decreases, even if you keep the dam empty. So that, by the application of operation scenarios, flood inundated area can be reduced to 100% in the floods whit peak discharge up to 500 m3/s.