2000-2014年中国重特大煤矿事故时空分布分形特征

本文汇总整理了2000-2014年中国发生的472起重特大煤矿事故,获得其空间分布状况;基于分形理论,利用网格法统计不同网格尺度下覆盖重特大煤矿事故的非空网格中的事故数量,计算煤矿事故的全国、三大自然地理区以及干湿分区的分维值,分析其空间分布分形特征;利用R/S方法研究15年来重特大煤矿事故发生的时间分形特征。研究表明,从全国范围来看,重特大煤矿事故具有较好的空间分形特性,但不同区域的重特大煤矿事故的分形特性却具有很大差别。15年来发生重特大事故数量及事故死亡人数逐年下降,由R/S分析得到的Hurst指数表明事故时间序列的分形特征客观存在,并且年发生事故数量及事故死亡人数量减少趋势。

The Fractal Characteristics of the Temporal-Spatial Distribution of Coal Mine Accidents in China from 2000 to 2014

The frequent occurrence of coal mine accidents has brought great losses to people's lives and threatened the safety of our country and residents. The fractal theory is a newly developed subject in recent years, and it has been turned into a powerful tool to describe the nonlinear problems. In this paper, analyses and discussions on the fractal characteristics of the temporal-spatial distribution and relativity as well as the regularity of the temporal distribution of the national catastrophic coal mine accidents from 2000 to 2014 in China have been calculated using the relevant methods of fractal theory. Firstly, based on previous studies, this paper summarized the coal mine accidents occurred between 2000 and 2014 in China and obtained the time of occurrence, latitude and longitude for each coal mine accident. Secondly, the grid method is used to measure the number of accidents in grids which cover the area of the coal mine accidents at different grid scale levels, including scales for the national wide region, the three dominating physical geographical regions and the arid and humid regions. We firstly numerate the accidents in every grid and calculate the information content for different grid scales. Then, a linear fit for the logarithms of the information content and grid scale is calculated, and as a result the absolute value of the line slope is taken as the fractal dimension. Finally, the Hurst exponent of the time series of the coal mine accidents is obtained by adopting the method of resealed range analysis (R/S Analysis). Results show that the fractal characteristics of the spatial distribution of China's coal mine accidents are objectively existent. But the fractal dimension values of the spatial distribution of the coal mine accidents in different regions are significantly different. Between 2000 and 2014, the number of total accidents and deaths peaked at 2005, and then it decreased gradually indicating that the safety situation of China's coal mine production keeps improving. The Hurst exponent of the time series obtained from the R/S analysis indicates that the fractal characteristics of the time series objectively exist and the decreasing trend is enhanced. Some opinions regarding the applications of fractal theory in coal mine accidents are put forward in the end.