新安江模型参数的不确定性分析

水文模型的不确定性研究是水文科学研究的重要课题。模型参数的不确定性分析是水文模型不确定性研究的重要内容之一。本文采用GLUE方法分析新安江模型参数的不确定性,结论基于对不同水文特征流域的长时间径流模拟,研究发现大量"等效性"参数组存在。据此将参数总结为三类:第一类为非敏感参数,如上层张力水容量UM等。它们对似然判据,及确定性系数(R²)影响小。第二类为敏感性参数,如河网蓄水消退系数CS等,其特点是对R²的影响大。第三类为区域性敏感参数,如张力水蓄水容量曲线的方次B等,它们对R²的影响力跟流域特征密切相关。这些结论有助于理解新安江模型参数,为今后流域水文模拟提供参考。文中还展望了未来水文模型不确定性研究的发展方向。

Uncertainty analysis of Xinanjiang model parameter

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.