Time-Series Fractal Characteristics of Sandstorm Frequency in Hexi Corridor
Jian Xu · Zhongguo shamo · 2003
Many researches have been made about sandstorm based on correlative data, and the work mainly focused on the history datas arrangement and statistical analysis, but the inherent nonlinear trait of sandstorm is studied less.Based on the annual frequency data of sandstorm occurring from 1961-1990 in Hexi corridor, the timeseries phase space is reconstructed and Kolmogorov entropy is calculated. The results show that sandstorm timeseries has fractal characteristics and its correlative dimension is 552, which indicates that there should have at least 6 independent variables for describing sandstorm change characteristics and reconstructing a dynamic system. Kolmogorov entropy of sandstorm timeseries is 018, which indicates that sandstorm dynamic system is chaotic and the forecasting timescale is about 5～6 years.Based on R/S analysis of every sandstorm period from 1961-1990, all the periods have persistence change except the period of 1973-1978, and the results are quite consistent with actual changing trend of sandstorm timeseries. The method is effective for studying fractal characteristics of sandstorm timeseries in Hexi corridor.