Improvement and Analysis for Accuracy of Baseflow Using SWAT-CUP Premium in the Yongjeon Stream, South Korea

Abstract Here, SWAT simulation results are calibrated and validated using SWAT-CUP Premium, and R 2 (coefficient of determination) values of simulated and observed flows are compared. According to the SWAT analysis of Cheongsong Yongjeon-stream basin, a low accuracy of 0.40 was the R 2 (coefficient of determination) value for simulated and observed flows, and the base flow was calculated at an annual average of 46.659 m 3 /s. During the same period, after calibration and validation using SWAT-CUP Premium, the R 2 value of simulated and observed flows was improved to 0.71, and the evaluation indexes showed that NS was 0.51, PBIAS was 37.1, P-factor was 0.73, and R-factor was 0.33, indicating that the relationship between observed and simulated flows was improved. In addition, after calibration and validation, the base flow was 56.951 m 3 /s, which was a more accurate value compared to the one before calibration and validation.