Comparison of temporal prioritizing of flooding in different hydrological periods (Case study: Kooshkabad sub-watersheds in Razavi province)

Flood Damage is one of the most important problems in many countries. There are different methods for flood controlling by using indentification of flooding areas. Because most of the watersheds have different flooding seasons, the present study is going to comparison of temporal prioritizing of flooding of Kooshkabad sub-watersheds in Razavi province using HEC-HMS model. In this study we used of SCS hydrologic simulation method at Rainfall-Runoff transformation on sub-watersheds area, and Muskingum routing method on main channels for abtain of watershed outlet flood hydrograph after determination of data for flood hydrograph. Than we calculated prioritization of sub-watersheds to point of flooding conception using HEC-HMS model and we calibrated it on initial adsorption and curve number and lag time parameters in springal and Summer-Autumnal hydrologic priods. Than we prioritized particitation amount of sub-watersheds on peak flood discharge and flood volume in every hydrologic period, using one to one delet of sub-watersheds in flood routing. Paired samples t-test have used for indication of significant difference to point of statistical in temporal prioritizing of sub-watersheds flooding.The results of this research show that participitation amount of sub-watersheds on outlet peak flood discharge and flood volume in different periods is significant.