남강댐 상류 소유역의 유출량 추정을 위한 SWAT 모형의 적용성 평가

Abstract

The objective of this study was to evaluate the applicability of SWAT (Soil and Water Assessment Tool) model for runoff estimation in the Nam riverdam watershed. Input data for the SWAT model were established using spatial data (land use, soil, digital elevation map) and weather data. The SWATmodel was calibrated and validated using observed runoff data from 2003 to 2014 for three stations (Sancheong, Shinan, Changchon) within the studywatershed. The R2 (Determination Coefficient), RMSE (Root Mean Square Error), NSE (Nash-Sutcliffe efficiency coefficient), and RMAE (RelativeMean Absolute Error) were used to evaluate the model performance. Parameters for runoff calibration were selected based on user’s manual andreferences and trial and error method was applied for parameter calibration. Calibration results showed that annual mean runoff were within ±5 % errorcompared to observed. R2 were ranged 0.64 ~ 0.75, RMSE were 2.51 ~ 4.97 mm/day, NSE were 0.48 ~ 0.65, and RMAE were 0.34 ~ 0.63 mm/day fordaily runoff, respectively. The runoff comparison for three stations showed that annual runoff was higher in Changchon especially summer and winterseasons. The flow exceedance graph showed that Sancheong and Shinan stations were similar while Changchon was higher in entire fraction.