Natural Flow Simulation in a Baisin considering Artificial Water Cycle

This study seeks to regionalize the parameters of the grid-based rainfall-runoff model (GRM) and simulate the natural flow considering an artificial water cycle. We established a water supply and demand network for the Han River basin, derived data related to the artificial water cycle through various organizations, and performed a water budget analysis by reflecting the simulated natural flow. When comparing the results of regionalization using only the Chungju Dam parameters and those using the Chungju Dam and Soyanggang Dam parameters, both results for the simulated flow showed good agreement with the observed flow, and the fitness evaluation results were also high (pentad: NSE 0.913–0.977, KGE 0.795–0.935, CC 0.974–0.995). The natural flow simulated by the GRM and TANK indicated that both models were able to reproduce the observed data well. Water budget analyses were performed for different time intervals, and daily analysis exhibited relatively lower fitness than pentad analysis (daily NSE 0.887-0.963, KGE 0.792-0.928, CC 0.960-0.990), but no significant difference was observed. The results indicated that the simulation of natural flow through the GRM was appropriate, and the model was sufficiently applicable to a disturbed watershed.