Estimating Floods of Various Return Periods for Babolrood Catchment Using WMS Model

Flood hazard assessment is an important topic that can reduce flood-related losses. Rainfall-runoff modeling plays a key role in the management of water resources in addition to protecting from flood hazards. The use of hydrological models to simulate the runoff necessitates the proper calibration of the different parameters. Therefore, In the present study, the Watershed Modeling System (WMS11.0) was evaluated to simulate peak discharge and volume of floods of Babolrood catchment. WMS model calibrated and validated using 3 and 2 rainfall events, respectively. Afterwards, design precipitation (DP) for 2, 5, 10, 25, 50, 100 and 500-year return periods was determined and flood resulting from DPs simulated. The results showed that the WMS model could accurately estimate the peak discharge (the error was about 5%) and the and flood volume (the error was less than 26%). But the model was not able to simulate properly the shape of the hydrograph. It also revealed that peak discharge and flood volume arising from 2 to 500-year return periods of rainfall vary between 50 to 300 m3/s and 6.6 to 32.4 Mm3, respectively.