水文模型不确定性研究方法耦合分析

Coupling Analysis of Research Methods for Hydrological Model Uncertainty

为了探索解决在提高区间覆盖率的同时降低预测区间平均带宽的问题,将dual EnKF方法与GLUE方法2种水文模型不确定性研究方法进行了耦合分析,得到了dual E-G方法。以新安江模型为例,采用3个评价指标(覆盖率、平均带宽和平均不对称性)评价了dual E-G方法在3个流域(甲河流域、天河流域、灞河流域)的预测区间性质,并与GLUE方法进行了对比。结果表明:dual E-G方法可以同时改善3种不确定性指标。该成果可为水文模型预报、洪水决策风险分析等方面的深入研究提供有益参考。

To reduce the average bandwidth of the forecast interval while increasing the interval coverage,this paper conducted a coupling analysis of dual EnKF and GLUE,two methods to research the hydrological model uncertainty and obtained the dual E-G method.Taking the Xin’anjiang model as an example,the paper used three evaluation indicators(i.e.,coverage,average bandwidth and average asymmetry)to evaluate the interval properties of the dual E-G method in three river basins(i.e.,the Jiahe Basin,Tianhe Basin and Bahe Basin)and compared the proposed method with the GLUE method.The results show that the dual E-G method can improve three kinds of uncertainty indexes at the same time.The results can provide a useful reference for further study on hydrological model forecasting and flood decision-making risk analysis.