 This study examined the calibration of hydrologic models in the three gorges reservoir area, TGRA. The researchers used the GLUE method in combination with the soil and water assessment tool, SWAT, to identify the most important parameters affecting stream flow and sediment simulation. They found that the parameters which had the greatest effect on the final simulation output were those related to the catchment processes, while the channel processes had a significant influence on the sediment simulation. Additionally, they identified several parameters which were not identifiable, meaning that different parameter ranges could produce the same result. As a result, it was concluded that caution must be exercised when calibrating hydrologic models in regions like TGRA, as the parameters may lead to equifinality. This article was authored by ZY Chen, L Chen, and T Chen.