Predictable time and trend analysis of the sediment time series at some control sections along the Yellow River
MA Jian-hua, LI Xiao-gai · Journal of Sediment Research · 2008
Sediment concentrations from 1952 to 2000 were chosen as the time series at Toudaoguai section,Tongguan section,Huayuankou section and Lijin section along the Yellow River.Kolmogorov entropy(K_2)~(-2) was calculated according to Zhao Gui-bing arithmetic,and Hurst index(H) according to R/S analysis.The results show that(1) Kolmogorov entropy is 0.13 at Toudaoguai section,0.37 at Tongguan section,0.40 at Huayuankou section and 0.38 at Lijin section,so the dynamic systems controlled by the different sections of the Yellow River basin are chaotic systems and the chaotic degrees heighten gradually from the upper to lower section.(2) At Toudaoguai section,the forecast time of the sediment time series is about 8 years,and the other sections are 3 years.The more obvious the chaos is,the shorter the forecast time is.(3) Hurst indexes at all study sections are more than 0.5,the maximum is 0.86 at Tongguan section and the minimum is 0.68 at Toudaoguai section,which indicates that the changes of the time series have continuous descending trends.