关键词: 河西走廊, 沙尘暴, 分形, 相空间重构, R/S分析

Abstract: Many researches have been made about sandstorm based on correlative data,and the work mainly focused on the history data's 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 time-series phase space is reconstructed and Kolmogorov entropy is calculated.The results show that sandstorm time-series has fractal characteristics and its correlative dimension is 5.52,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 time-series is 0.18,which indicates that sandstorm dynamic system is chaotic and the forecasting time-scale 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 time-series.The method is effective for studying fractal characteristics of sandstorm time-series in Hexi corridor.

Key words: Hexi corridor, sandstorm, fractal, phase space reconstruction, R/S analysis