改进的相空间模式及其在月流量预测中的试验研究  

Improvement on Equal Distance Model of Near Neighborhood in Phase Space and Its Application in Monthly Flow Prediction

作　　者：强学民[1] 葛朝霞[2] 曹丽青[2] 

机构地区：[1]南京大学大气科学系,江苏南京210093 [2]河海大学水资源环境学院,江苏南京210098

出　　处：《水电能源科学》2006年第1期72-76,共5页Water Resources and Power

摘　　要：讨论了基于混沌理论的相空间近邻等距模式及该理论中的预见期T、延迟时间τ、相空间维数d等,提出了实际应用中根据预见期T建立的新时间序列,满足T=τ=sδt,消除了相空间时滞τ的变化对T的影响。应用改进前、后的预报模式以不同相空间维数d对水文月平均流量进行逐月的预报试验和检验。结果发现,改进后的模式提高了预报准确率,延长了预报时效,尤其是提前1 a的最佳预报效果。Many studies show that nonlinearly chaotic properties probablyexist among hydrological systems.By introducing phase space reconstruction techniques of chaotictheory,it can find out the conventional undiscovered climatologic dynamics,and will lead to a new path of climatology predictions.Previous studies in meteorological field mainly focus on identifying the properties of time series and carrying out forecasts month by month with different models.Few work has been done on how to improve the predictability and extend the prediction time.In this paper,an improvement on the equal distance model of near neighborhood in the phase space is proposed.In practical applications,it is found that a new time series can be established based on the prediction time to meet the requirement that the prediction time T and the delay time should be the same,that is,T=τ=sδt.This can remove the influence of T upon τ.The newly improved model is applied in the experiments for predicting the time series of monthly fow in Yichang.The predictions in 8 years (1996-2003) show that,the improved model has a relative higher predictability than before(especially in yearly predictions),so a longer prediction can be available.

关 键 词：水文预报 混沌 相空间 近邻相似等距模式 

分 类 号：P338[天文地球—水文科学]