Uncertainty analysis of Xinanjiang model parameter
新安江模型参数的不确定性分析

The uncertainty problem in hydrological model is an important issue of scientific research at present,which covers three aspects of data,model structure and parameters.Parameter is one of the key roles in analyzing model uncertainty problem.The value of parameters depends on characteristics of a basin,but in fact it is difficult to obtain because there are few observation stations.In general,it needs to confirm parameters by several calibration methods including Genetic Algorithm,Simulated Annerling and Artificial Neural Network.So there exists parameter uncertainty problem.The generalized likelihood uncertainty estimation(GLUE) methodology is an effective approach to study uncertainty of parameters.In this paper,the uncertainty in Xinanjiang model is examined by employing GLUE.Based on the simulation results of daily data from Jiuzhou(1978~1987) and Lushi(1980~1988) basins,it is found that the phenomenon of "equifinality" exists among parameters groups for both of the basins.According to comparison result of scatter plots,parameters of Xinanjiang model can be classified into three groups: sensitivity parameters such as UM,EX;non-sensitivity parameters such as KC,CS and regional sensitivity parameters such as B,WM.The conclusion is favorable for understanding parameters of Xinanjiang model so as to provide valuable scientific information for simulating hydrological processes.Finally it puts forward the main contents on future uncertainties research in hydrological modeling.