强震复发概率模型中的参数不确定性研究

Parameter uncertainty analysis on probability model of strong earthquake recurrence

在强震发生概率计算过程中,往往只考虑参数的随机不确定性,却很少考虑参数的认知不确定性.本文以布朗过程时间(BPT)模型为例,利用贝叶斯估计法定量分析了强震平均复发间隔的认知不确定性;研究了在强震发生概率计算过程中如何考虑这种认知不确定性.结果表明:采用不同的强震复发间隔参数估计方法,所得的参数认知不确定性存在明显差异;在计算强震发生概率时,是否考虑参数认知不确定性所得的结果存在较大差异.

In the process of calculating probability for large earthquake occur- rence, traditional methods often only consider aleatory uncertainty, but episte- mic uncertainty is rarely taken into account. This paper takes Brownian passage time （BPT） model as an example, epistemic uncertainty of mean recurrence interval of large earthquakes is analyzed quantitatively by using Bayesian estimation method, and bow to take epistemic uncertainty into the calculation of the occurrence probability of large earthquake is also studied. The results show that there is significant difference in parameter uncertainty among different methods for determining mean recurrence interval of large earthquakes, also there is remarkable difference between the results with and without considering the epistemic uncertainty of parameters in the process of calculating the probability for large earthquake occurrence.