用褶积滤波及多元回归方法处理聊古—1井氮氦比观测资料

聊古-1井位于聊城——兰考断裂带北段。自1981年以来对该井氮氦比每日进行观测,其主要干扰因素为降雨和井水流量。其中降雨对氮氢比观测的影响不是简单的线性关系,而是带有滞后记忆效应的非线性关系。为此,我们采用了非线性的褶积滤波的方法,来处理降雨对氮氦比的影响。为了消除井水流量变化对氮氦比的影响,同时采用了多元回归的方法,对氮氦比观测值进行综合处理。在以上处理的基础上,分析了1981年宁晋地震和1983年菏泽地震前,氮氦比的变化特征。两次地震前的2个月左右,氮氦比值都出现了明显地高值异常,且均在异常转折、恢复的过程发震。所以这一规律可做为该井氮氦比地震短期前兆异常指标。

THE PROCESSING OF OBSERVATION DATA OF THE RATIOOF NITROGEN TO HELIUM IN WELL LIAOGU-1 USINGFALTUNG FILTERING AND MULTIPLE REGRESSION

The ratio of nitrogen to helium (N/He) in the well Liaogu-1 located in the north segment of the Liaocheng-Lankao fault has been observed daily since 1981 and it is found that observation results arc disturbed mainly by precipitation and the flow of the well water. In order to eliminate the interference factors, nonlinear faltung filtering is adopted to remove the precipitation factor which influence the observation of N/He in nonlinear relation with delayed memory effect and multipe regression is used to remove the influence of the flow of well water and process comprehensively the observation data of N/He. On the basis of processing, the variation chacteristics of N/He before the 1981 Ningjin earthquake and the 1983 Heze earthquake are analysed. The results show that the high anomalous values of N/He appeared two monthes before the two earthquakes and the earthquakes occurred in the process of transition and restoration of the anomalous curve. Therefore, the variation pattern could be an anomalous index of short-term earthquake prediction of N/He in the well.