汶川地震前地下水位固体潮加卸载响应比异常分析

Analysis on Earth Tidal Loading/Unloading Response Ratio of Groundwater-Level Before Wenchuan Earthquake

针对汶川地震前地下水位中短期异常信息比较不明显这一问题,选取受地震影响严重的川、滇、陕、甘及渝等5个省市为研究范围,依据加卸载响应比理论,采用固体潮加卸载响应比方法对地下水位动态进行分析。结果表明:汶川地震前中短期时间内,地下水位固体潮加卸载响应比存在着明显的异常现象,异常时间相对集中在震前半年左右或1～2个月,且随着地震孕育活动的增强,异常井的空间分布也逐渐由四周向龙门山断裂带附近靠拢,尤其在震前1～2个月时间内,震源区异常井数量明显多于其它地区。

To solve the problem that the mid- and short-term anomaly of the groundwater-level is not obvious before the 2008 Wenchuan, Sichuan Earthquake, we select the areas such as Sichuan Province, Yunnan Province, Shanxi Province, Gansu Province and Chongqing City which were seriously affected by the earthquake to analyze the earth tidal loading-unloading response ratio （LURR） through the dynamics of the groundwater-level. The results turn out that earth tidal LURR of groundwater-level is obviously abnormal in mid-short term before Wenchuan Earthquake. The abnormal time appeared half a year or 2 months or 1 month before the earthquake and the abnormal wells would gradually appear from distant areas to the near areas of Longmenshan Fault in the time process of the earthquake genesis. Especially within the period from 1 to 2 months before the earthquake, the number of abnormal wells in the focal area would obviously become more than those in other area.