基于概率增益模型的强震概率预测研究

Research on Strong Earthquake Probability Prediction Based on the Probability Gain Model

为提高云南地区及邻区强震中短期预测的准确度,通过强震发生前不同地震前兆指标的对比研究,发现仅用单项指标很难提高预测的准确度。挑选出能从不同侧面反映强震发生规律的6项指标,采用概率增益模型对这些指标进行综合处理,通过估算每种地震前兆的概率增益来定量判定地震发生的可能性,最终得到可用来预测云南地区及邻区M≥6.0地震未来中短期发生可能性大小的综合概率P指标。计算分析表明:①使用综合概率P预测未来半年云南地区及邻区M≥6.0强震,能通过R值检验;②取P异常阀值为20%、30%,可对强震进行不同级别预警,P值小于20%为安全,P值为20%~30%为黄色预警,为云南地区及邻区未来存在发生M≥6.0地震的可能性;P值大于30%为红色预警,表示未来半年云南地区及邻区将发生M≥6.0地震。

In order to improve the accuracy of short-and medium-term prediction of strong earthquakes in Yunnan and its adjacent area,through the comparative study of different earthquake precursor indexes before strong earthquake,we find that using only one single indicator is difficult to improve the accuracy of prediction.We select 6 indexes which all reflect the occurrence law of strong earthquakes from different aspects.We use the probability gain model to synthetically process these indicators by estimating the probability gain of each earthquake precursor to quantitatively determine the possibility of the earthquake.Finally,we obtain a synthetic probability P index to predict the probability of short-and medium-term occurrence of 6-magnitude earthquakes or above in Yunnan and its adjacent area in future.The results show that:①The comprehensive probability P can pass the R-value test for predicting 6-magnitude earthquakes or above in Yunnan and its adjacent area in the next six months.②Taking P abnormal threshold as 20%and 30%,different levels of strong earthquake warning can be carried out,a P-value less than 20%indicates“safety”;a P-value greater than 20%indicates that a“yellow warning”is necessary,indicating that there is a possibility of a 6-magnitude earthquake or higher may occur in Yunnan in future;a P-value greater than 30%indicates the need for a“red warning”,indicating that a 6-magnitude earthquake or above will occur in Yunnan and its adjacent area in the next six months.