河流系统实时洪水预报误差多点联合校正方法研究

Study on multi-point joint correction method for real-time flood forecasting errors of river systems

实时校正是改善洪水实时预报精度的重要手段。河流系统中多个站点之间具有高度的水力联系,各个站点之间的误差也具有空间关联性。依据河道水流演进的基本方程和动态自适应的自回归方法,建立了考虑误差空间演化的河流系统实时洪水预报误差多点联合校正方法。利用洪峰段洪量误差、洪峰流量误差、纳什效率系数(NSE)和峰滞时间等指标分别对多点联合校正和不考虑误差空间关联性的单点校正开展校正效果评估。以淮河王家坝断面以上为背景开展实证研究,结果表明:考虑河流系统误差空间关联性的多点联合校正效果优于单点校正,洪峰段效果更为显著,能够更有效地提高河流系统洪水预报的精度。

Real-time correction is an important way to improve the accuracy of real-time flood forecasting.There are high-level hydraulic connections among the multiple stations in a river system,and the errors between the multiple stations are spatially interconnected as well.Based on the basic equations of river flood routing and the dynamic adaptive autoregressive method,this study proposed a multi-point joint correction method for real-time flood forecasting errors with consideration to the spatial evolution of errors.The correction effect was evaluated in terms of the flood volume error during flood peak period,flood peak discharge error,Nash-Sutcliffe efficiency coefficient,and lag time of peak.This paper conducted a case study on the region up the Wangjiaba section of Huaihe River to demonstrate the proposed methodology.The results indicated that the effect of multi-point joint correction was better than that of single-point correction,and the effect was even more prominent for the flood peak period.The proposed method can effectively improve the accuracy of flood forecasting of the river system.Key words: