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

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