Uncertainty Analyses of streamflow simulation in Fenghe watershed using SWAT model

• 1、College of Water Sciences,Beijing Normal University
• 2、College of Water Sciences,Beijing Normal University,Beijing 100875

Abstract：Hydrological model is an essencial tool for integrated water resources management, and the uncertainty of hydrological models should not be overlooked when it's applied. Using Fenghe watershed as the study area, this paper analyzed the uncertainty of streamflow simulation by the GLUE methodology and SWAT model, as the main research object, and discussed the impact of the likelihood function value of the GULE method for the uncertainty of streamflow simulation and the relationship between runoff characteristics and the uncertainty. The results show that the parameters CN2, ALPHA_BF, GW_DELAY and SOL_AWC are sensitive, and this model can simulate Fenghe watershed runoff process, but the confidence intervals of simulated runoff process does not fully cover the actual process of streamflow. Moreover, with the increasing of likelihood function value, the coverage rate of confidence interval changed little, but its width decreases significantly. Simultaneity there is a good consistency between Interval width and mean and standard deviation of annual runoff, but no significant correlation exists between the coverage rate and runoff characteristics.

Keywords： Uncertainty Analyses SWAT model GLUE methodology Fenghe Watershed