GCM 공간상세화 방법별 기후변화에 따른 수문영향 평가- 만경강 유역을 중심으로 -

Abstract

The objective of this study is to evaluate hydrologic impacts of climate change according to downscaling methods using the Soil and Water AssessmentTool (SWAT) model at watershed scale. We used the APCC Integrated Modeling Solution (AIMS) for assessing various General Circulation Models(GCMs) and downscaling methods. AIMS provides three downscaling methods: 1) BCSA (Bias-Correction & Stochastic Analogue), 2) Simple QuantileMapping (SQM), 3) SDQDM (Spatial Disaggregation and Quantile Delta Mapping). To assess future hydrologic responses of climate change, weadopted three GCMs: CESM1-BGC for flood, MIROC-ESM for drought, and HadGEM2-AO for Korea Meteorological Administration (KMA) nationalstandard scenario. Combined nine climate change scenarios were assessed by Expert Team on Climate Change Detection and Indices (ETCCDI). SWATmodel was established at the Mankyung watershed and the applicability assessment was completed by performing calibration and validation from 2008to 2017. Historical reproducibility results from BCSA, SQM, SDQDM of three GCMs show different patterns on annual precipitation, maximumtemperature, and four selected ETCCDI. BCSA and SQM showed high historical reproducibility compared with the observed data, however SDQDMwas underestimated, possibly due to the uncertainty of future climate data. Future hydrologic responses presented greater variability in SQM andrelatively less variability in BCSA and SDQDM. This study implies that reasonable selection of GCMs and downscaling methods considering researchobjective is important and necessary to minimize uncertainty of climate change scenarios.