Abstract:

In the paper,the chaotic characteristics of hydrological time series from the stations which entering into Poyang lake basin were analyzed.In order to make full use of the abundant evolvement information contained in the monthly runoff series from 1955~2001 on Waizhou,Lijiadu and Dufengkeng stations,the method of CC was used to select the lag time 〖WTBX〗τ〖WTBZ〗 and the phase space of dimensions 〖WTBX〗m〖WTBZ〗.The main quantitative indices such as saturated correlation dimension and the maximum Lyapunov exponent of the monthly runoff series,which could be taken as the chaos features of the hydrology system,were calculated.The saturated correlation dimension was estimated by GP method，and maximal Lyapuonv exponent was calculated by Rosenstein method.The calculated results indicated that monthly runoff time series of the Waizhou,Lijiadu and Dufengkeng stations were all nonintegers.At the same time,the maximum Lyapunov exponents gained from the datum were all positive numbers,which sufficiently showed that the runoff system of Waizhou,Lijiadu and Dufengkeng stations had fractal characteristics and chaotic characteristics.The saturated correlation dimension and the maximum Lyapunov exponent of the monthly runoff series showed that the monthly runoff series was most complex at Waizhou station,the Lijiadu station was secondary,and the Dufenkeng station was least complex.