Hydrologic uncertainties in climate change from IPCC AR4 GCM simulations of the Chungju Basin, Korea

► Hydrological models and PET methods are the main uncertainty sources in climate impacts study. ► Uncertainty from hydrological model and PET is greater in the distant future than in the near future. ►The uncertainty in runoff change is smaller for the wet period than for the dry period. ► More caution is needed in assessment of future changes in the risk of low flows and droughts.