A comparison of two event-based flood models (ReFH-rainfall runoff model and HEC-HMS) at two Korean catchments, Bukil and Jeungpyeong

This study tests the Revitalised Flood Hydrograph (ReFH) rainfall runoff model at two Korean catchments (Bukil and Jeungpyeong) and its application results are compared with HEC-HMS model. These two rainfall-runoff models are conceptual models, which are widely used as a standard tool in UK and Korea. The flood events (Bukil-8 events and Jeungpyeong-6 events) are applied to ReFH model and HEC-HMS with calibration and validation approaches. The main findings of this study are. a) ReFH model shows a potential as a rainfall runoff model for Korean catchments. Although it is not an overwhelmed comparing to HEC-HMS, the performance in objective function (NSE*) and simulated hydrographs in calibration/validation are promising. b) The results of general and cross validation indicate that ReFH could provide acceptable simulations in the flood events, which HEC-HMS fail to simulate and HMS has wide spectrum of the model performance. c) ReFH model shows the limitations in the simulation of peak flow in large catchment, Bukil (906.6 km2), while HEC-HMS shows good simulations in both catchments. It is due to a lumped concept in the ReFH modeling and the semi distributed modeling concept of HEC-HMS is important in the peak flow in large catchment. Further study will focus on testing the ReFH rainfall runoff model with the wide ranges of catchments in Geum river basin. It is necessary to generalize this study and build up the data base for the further regionalization of rainfall runoff model in Korea.