排除降雨干扰后的地下水位异常与强震预报

Groundwater Level Anomalies after Eliminating Rainfall Influence and Predictions of Strong Earthquakes

选取云南地区受年度降水影响显著的10口地下水位观测井,对观测井所处地区年降雨量及次年水位谷值变化进行分析,提取了水位年异常特征。发现出现异常年份的异常台项比与次年的M≥6和M≥7地震有较好对应关系。1987年以来,出现异常台项比≥0.5的年份有7年,对应云南及邻区次年M≥7地震4次,对应率为57%;异常台项比≥0.4的年份有10年,对应次年M≥6地震9次,对应率90%。用此方法可以对云南的年度最大地震活动水平和地震强度进行预测估计。

We selected 10 groundwater level observational wells in Yunnan that are remarkably influenced by rainfall, analyzed the relation between the annual rainfall and the lowest groundwater level in the following year and obtained the annual abnormal character of groundwater level. It is found that the ratio of abnormal stations to total stations in an abnormal year corresponds to M≥6 and M≥7 earthquakes in the following year very well. There have been seven years in which the ratio of abnormal stations is more than 0.5 since 1987, and four M≥7 earth- quakes happened in Yunnan and vicinity in the following year, the corresponding rate is 57% ; there have been ten years in which the ratio of abnormal stations is more than 0.4, and nine M≥6 earthquakes happened in Yunnan in the following year, the corresponding rate is 90%. We can use this method to estimate annual maximal seismicity level and seismic intensity in Yunnan.