Abstract: The atmospheric precipitation data of three seismic stations,Fengtai of Beijing,Dingxiang of Shanxi Province and Changli of Hebei Province,are studied using the moving average method for monthly means and the subordinate function method.The results indicate that there exist obvious medium-term and mid-short-term atmospheric precipitation precursory anomalies before the 1976 Tangshan M_S 7.8 earthquake,the 1981 M_S 5.6 Fengzhen earthquake,the 1989 Datong M_S 5.9 earthquake,the 1998 Zhangbei M_S 6.2 earthquake and the 2006 Wen'an M_S 5.1 earthquake.Furthermore,these anomalies are well consistent with precursory anomalies of water level,water radon and ground deformation.The relationship between atmospheric precipitation anomaly and earthquake can be interpreted using the "the water trigger mechanism".The atmospheric precipitation anomalies are external cause and not essential signal of earthquake.The atmospheric precipitation anomalies are related to the occurrence time of earthquake and can be used for medium and short term prediction of earthquake,its predictive period is about 4～14months.It would be practicable and necessary to try out the atmospheric precipitation anomaly method for earthquake prediction.

Key words: atmospheric precipitation, medium-term precursor, mid-short-term precursor, 23-point smooth, 11-points smooth, subordinate function

摘要： 引用地下流体异常的判定方法,即月均值滑动平均法和从属函数法,处理了北京丰台、山西定襄、河北昌黎3个地震台的降水资料。结果表明,在降水的原始曲线上,降水量异常显示比较模糊;而经过定量处理后,降水存在着明显的中期和中短期异常变化。降水异常与1976年唐山7.8级、1981年丰镇5.6级、1989年大同5.9级、1998年张北6.2级及2006年文安5.1级等多次地震的对应关系良好;与水位、水氡、地形变异常之间有着十分密切的呼应关系。降水异常与地震的关系可用"水诱发机理"来解释;降水异常属于外因性前兆,为非必震信号。降水异常与发震时间的关系密切,可用于地震的中短期预测,其预测期为4～14个月。

关键词: 降水量, 中期前兆, 中短期前兆, 23点平滑, 11点平滑, 从属函数