Author(s): Dereje Birhanu; Hyeonjun Kim; Cheolhee Jang; Sanghyun Park
Linked Author(s):
Keywords: CAT; GR4H; Flood modeling; Korean watersheds
Abstract: In this study, two hydrological models were applied to simulate twenty-two flood events in three selected Korea watersheds. The Catchment hydrological cycle Assessment Tool (CAT) and Génie Rural a 4 parametres Horaire (GR4H) models were applied to assess the different flood events of Seolmacheon (8.5 km²), Pangyo (22.9 km²) and Bukil (906.6 km²) watershed. The CAT, a physically based semi-distributed hydrological and GR4H, the lumped conceptual rainfall-runoff model were calibrated against hourly observed streamflow data for each flood events and cross-validated for selected flood events. The model performance was evaluated considering the Nash-Sutcliffe efficiency (NSE) as basic objective function. The comparative assessment of both models captures fairly all flood events in the calibration period. The minor better performance of GR4H is because of the automatic calibration adopted for parameter optimization. In contrary, CAT model performs better in cross-validation of most flood events whereas GR4H fall to perform better in the two small watersheds. The saturated hydraulic conductivity and routing store were the most sensitivity parameter which affects the total volume, peaks flow and time. In general, the two model result shows comparable performances both in the calibration and validation periods regardless of their different conceptualization in model development. The main finding of the study shows the potentials of CAT and GR4H model to be used for flood forecasting in Korea basin and it provides information for decision-makers regarding on the physical parameters which affect the flood events.
Year: 2018