K_(cv)值在河北及邻区地震预测中的应用研究

Application of K_(cv) Values in Forecasting Earthquakes in Hebei and its Neighboring Regions

地震空间分布非均匀性指标Cv值作为一种有效的预测指标近几年来得到了广泛应用。然而受空间分布的事件样本数大小的影响,Cv值会有所改变。本文采用Cv值标准化后的Kcv值,统计了河北及邻区的地震事件空间非均匀性分布,并与地震时空概率增益综合预测模型相结合,进行研究区地震预测。依据河北及邻区40多年的地震观测资料进行了Kcv值扫描和震例统计,研究了该方法应用于河北地区的预测效能及最优时间尺度。对研究区2008—2012年M5及以上地震的概率增益、地震发生概率预测与实际地震发生情况的回溯性检验结果表明,此方法应用于河北地区地震发生概率的预测是可行的。依据上述方法,对2013—2017年河北及邻区M5及以上地震发生的概率增益和地震发生概率进行了预测。

As an effective prediction index, the spatial distribution heterogeneity parameter Cv of seismicity has been widely used in recent years. However, Cv value can change with the different sample size of spatial distribution events. In this paper, Cv value is normalized as Kcv value, we counted the spatial heterogeneity distribution of earthquake events in Hebei and its adjacent regions, and combined with spatial-temporal synthetical probability gain model to study its feasibility in earthquake prediction. The prediction efficiency and the optimal time scale are calculated using theKcv value and earthquake case statistics over the past 40 years in the studied area. The feasibility and effectiveness of Kcv value method in earthquake prediction in Hebei region are further proved by analyzing its probability gain, and the probability of earthquakes greater than M5. 0 with the actual earthquake occurrences from 2008 to 2012. And predictions of the greater than M5.0 earthquake probability and probability gain from 2013 to 2017 are carried out in this area.