基于向量夹角余弦的水文组合预报方法

针对水文预报中单个水文预报模型预报精度不高的问题, 提出基于向量夹角余弦的水文组合预报方法. 该方法采用组合预测理论建立了实测向量、预报向量和权值向量, 形成向量夹角余弦模型; 根据不同的历史水文资料状况, 给出拟合优度和动态逼近两种可变权值计算方法, 完成参数的率定, 并将各参数对预报精度的影响加以分析. 实验表明: 该方法能够有效地克服单个水文预报模型的不足, 通过实现多个单项水文预报模型的组合, 可将预报合格率提升约20%.

Hydrological combined forecasting method based-on vector angular cosine

According to the low accuracy problem of single hydrological forecasting model in hydrological forecasting,a hydrological combined forecasting method was put forward based on vector angular cosine.Applying the theory of combination forecasting,this paper was to establish measurement vector, prediction vector and weight vector,to construct vector angular cosine model.This paper discusses fitting goodness and dynamic approximation as two variable weights calculation methods for different conditions of historical hydrological data;Completes calibration and initialization of parameters,and analyzes the influencing factors of forecasting accuracy by parameters.The results show that this method can effectively overcome the lack of individual hydrological forecasting,and achieve a combination model from individual hydrological forecasting with more than 20%pass rate.