The Relationship between Parameters of the SWAT Model and the Geomorphological Characteristics of a Watershed

Abstract

The correlation relationships and their corresponding equations between the geomorphological parameters and the Soil Water Assessment Tool (SWAT) model parameters by Sequential Uncertainty Fitting-version 2 (SUFI-2) algorithm of SWAT Calibration and Uncertainty Programs (SWAT-CUP) were developed at the Seom-river experimental watershed. The parameters of the SWAT model at the Soksa-river experimental watershed were estimated by the developed equations. The SWAT model parameters were estimated by SUFI-2 algorithm of SWAT-CUP with rainfall-runoff data from the Soksa-river experimental watershed from 2000 to 2007. Rainfall-runoff simulation of the SWAT model was carried out at the Soksa-river experimental watershed from 2000 to 2007 for the applicability of the estimated parameters by the developed equations. The root mean square errors (RMSE) between the observed and the simulated rainfall-runoffs using the estimated parameters by developed equations of correlation analysis and the optimum parameters by SUFI-2 of SWAT-CUP were 1.09 m 3 /s and 0.93 m 3 /s respectively at the Soksa-river experimental watershed from 2000 to 2007. Therefore, it is considered that the parameter estimation of the SWAT model by the geomorphological characteristics parameters has applicability. 속사천 시험유역 자료를 이용하여 SWAT 모형의 유출모의를 실시하였다. 실측자료와 지형학적 특성 매개변수의 상관관계 분석으로 산정된 매개변수를 이용하여 속사천에 적용한 유출 모의결과와의 RMSE (root mean square error)는 1.09 m 3 /s이고, SWAT-CUP의 SUFI-2 최적 매개변수를 적용한 유출 모의결과와의 RMSE는 0.93 m 3 /s으로 나타났다. 따라서 지형학적 특성 매개변수를 이용한 SWAT 모형의 매개변수 추정이 적용성이 있다고 판단된다.