SWAT 모형을 이용한 기후변화에 따른 만경강 유역에서의 수문 및 수질 영향 평가

Abstract

The objective of this study was to estimate the climate change impact on water quantity and quality to Saemanguem watershed using SWAT (Soil andwater assessment tool) model. The SWAT model was calibrated and validated using observed data from 2008 to 2017 for the study watershed. TheR2 (Determination coefficient), RMSE (Root mean square error), and NSE (Nash-sutcliffe efficiency coefficient) were used to evaluate the modelperformance. RCP scenario data were produced from 10 GCM (General circulation model) and all relevant grid data including the major observationpoints (Gusan, Jeonju, Buan, Jeongeup) were extracted. The systematic error evaluation of the GCM model outputs was performed as well. They showedvarious variations based on analysis of future climate change effects. In future periods, the MIROC5 model showed the maximum values and theCMCC-CM model presented the minimum values in the climate data. Increasing rainfall amount was from 180mm to 250mm and increasing temperaturevalue ranged from 1.7 to 5.9℃, respectively, compared with the baseline (2006∼2017) in 10 GCM model outputs. The future 2030s and 2070s runoffshowed increasing rate of 16∼29% under future climate data. The future rate of change for T-N (Total nitrogen) and T-P (Total phosphorus) loadspresented from -26 to +0.13% and from +5 to 47%, respectively. The hydrologic cycle and water quality from the Saemanguem headwater were verysensitive to projected climate change scenarios so that GCM model should be carefully selected for the purpose of use and the tendency analysis ofGCM model are needed if necessary.