淮河流域洪涝变化的混沌特征

SOME CHAOTIC CHARACTERISTICS OFTHE FLOOD SERIES IN HUAIHE RIVER BASIN

从功率谱结构、Ｌｙａｐｕｎｏｖ指数、吸引子维数和可预报时间等方面分析了淮河流域洪涝变化的混沌性质．研究表明．淮河流域洪涝变化是一类混沌变化序列，洪涝系统是一类混沌动力系统．系统对初值极端敏感，长期行为不可预报，其可报预时间约为５～６年．

Based on the chao theory, some chaotic characteristics of the flood series in Huaihe Riverbasin, that is the power spectrum, atracttor dimension and Lyapunov exponent are analyzed andthe predictabilities of the flood series are estimated.The power spectrum of the flood series in Huaihe River basin has the features of tha of chaotic series.Moreover, the fractal dimension of the flood series which is larger than 2.0 and not integral and positive Lyapunov exponent quantitatively testify that the flood series in Huaihe River basinis chaotic. Furthermore, some fractal dimensions of different moving average series of the flood seriesare analyzed. It shows that the fractal dimension demonstrates the systematic levels. The fractal dimension(4.66) of the flood series in Huaihe River basin shows that it should reconstruct 5-dimensional dynamicalsystem to simulate the real system of the flood series.The long-term forecast of the flood series in Huaihe River basin is unfeasible because the chaoticsystem is extrmely sensitive to the initial condition. However, the predictable analysis from secondpower Renyi entropy shows that the predictable duration of the flood series in Huaihe River basin isabout from 5 to 6 years.