自然灾害发生时间序列的分形特征及R/S分析

统计了公元960年到1979年我国地震、洪涝和台风风暴潮灾害发生的时间及死亡人数,以分形几何中的Cantor集合为模型,发现我国自然灾害发生时间序列的分布呈现出明显的分形特征,并采用Smalley方法分别计算了不同灾害发生时间序列分布的分维值,它们均在0.5左右,同严格意义上的数学分形Cantor集合相比分维较小,说明我国地震等自然灾害发生发展的自组织程度还有进一步发展的趋势,其危害程度将可能进一步提高;在自然灾害发生时间序列的分形特征的基础上,通过R/S分析,得出3种自然灾害发生时间序列的H指数均在0.28左右,同日斑指数、树木年轮、湖泊水位变化等自然现象相比较小,说明自然灾害的发生具有短程相关性,其发生规律没有日斑指数等自然现象明显.该研究对于进一步认识和研究我国地震等自然灾害的发生规律和发展趋势等具有一定意义.

Fractal characteristics and R/S analysis of time series of natural hazards

Each year thousands of people lost their lives because of natural hazards in our country.In this article,based on the statistics of time when natural hazards occurred and the deaths caused by the natural hazards between 960 A.D and 1979 in Chinese history,time series of natural hazards such as earthquake,flood and typhoon were separately set up and obvious fractal feature was found existed according to the Cantor model from fractal theory.However,the fractal dimensions are all smaller than that of Cantor model.Such results make it out that the self-organizational degree of the natural hazards has the trend of further evolution and their dangerous degree will improve at the same time.What's more,through R/S analysis,H index of different type of natural hazard were calculated,which is smaller than that of familiar natural phenomenon such as the activity of macula,the changes of water level of lake or river,the tree-ring,and so on.Smaller H index indicates that the occurrence of natural hazards have only short-range correlation and their occurrence regularity or periodicity is not obvious.This research is of certain theoretical significance to the recognition and research on the occurrence rule and developing trend of natural hazards.