嫩江流域径流的可预报性及其时间尺度分析

本文在阐述径流过程主要影响因素和表现特征基础上,采用混沌理论,对于嫩江流域月径流过程系统进行了延滞时间、嵌入纬度、关联维数等计算,进而进行相空间重构,计算出其最大Lyapunov指数为0.13,说明该系统具有混沌特征.初步得出如下结论:①嫩江流域中长期径流预报的预见期为7～8个月;②"数据驱动模型"对于中长期径流预报更有其方法的适用性;③中长期径流预报计算时段应以月为单位.

Analysis of Predictability and Time Scales for the Nenjiang River Runoff

In this paper, chaos theory was used to compute delay time,embedding dimension and strangeness of strange attractors of the monthly runoff process of the Nenjiang River based on the main influencing factors and the expressive characteristics of the runoff process. And then the phase space was reconstructed and the value of the maximum Lyapunov exponent was 0.13, which indicated that the system is characteristic by chaos. The initial conclusions are as follows:① The forecast period of the long- and medium-term runoff forecasting of the Nenjiang River ranges from 7 to 8 month. ② Data-Based Model is more suitable for long-and medium-term runoff forecasting.③ The unit of the calculation interval of the long- and medium-term runoff forecasting should be month.