三峡水库区滑坡时间记录的R/S分析

R/S analysis of landslide time record in the Three Gorges Reservior Area

文章对统计的三峡库区滑坡的发生时间和规模运用时间记录分析,得到滑坡发生的年份统计规律及其发展趋势。首先对所有规模大于等于1×104m3滑坡进行分析,然后将这些滑坡按其规模划分不同等级,分别运用R/S方法进行时间记录分析,结果表明:不同规模等级滑坡的Hurst关系具有相似的特征,这一结果反映了不同规模等级的滑坡之间的统计相似性。研究区滑坡时间分布的Hurst指数均大于0.5,表明了滑坡发生具有规律和随机的双重性质。而Hurst指数偏离0.5的程度就衡量了随机性因素与确定性因素在滑坡时间分布中所占的比重。运用R/S方法,可以对一定时间范围内的滑坡涨落做出估计。

The R/S method is the rescaling range analysis which studies the change of rule of statistical characteristic of the natural phenomenon by changing the size of study scale. According to the analyse of landslide time record in the Three Gorges Reservior, this paper gets the rule of annual statistic and the developmental trend of the landslides. By the R/S method, it takes the time record analyse to the landslides with their volume equal or more than 1 ×10^4m^3 and the different ranks of these landslides. There is the experience relation of Hurst ： R/S = Cτ^H . The value of H of the landslides with their volume equal to or more than 1 × 10^4m^3 is 0.73, and the value of H of different rank of volume is about 0.71. The results indicate which the relations of Hurst of landslides with different volume have similar characteristic. This result reflects the statistical similarity among the landslides of different volume. The indexes of Hurst of the landslides time distribution are more than 0.5 which indicate the orderliness and randomicity of landslides occurrence. But the extent which the index of Hurst departure 0.5 indicate the proportion of the randomicity and certainty in the landslides time distribution, using the R/ S method, we can estimate the fluctuation of landslides in the definite time range.