天津潘庄井水位突升异常的调查与分析

Investigation and Analysis on the Jumping Anomaly of Water Level from Panzhuang Well in Tianjin

咸水层是华北沿海平原地区特有的含水层。多年观测实践表明,咸水层水位动态表现出较好的映震能力。天津宁河潘庄井是现存的一口咸水观测井,水位动态一般较为稳定,日变幅度小于10cm。多年来该井在首都圈尤其是唐山老震区中等以上地震前有很好的水位异常显示。2010年5月该井水位出现大幅度突升异常,上升幅度近3m这种显著的异常变化是与地震孕育有关,还是由其他因素引起的干扰变化,需要给出一个科学的判定意见,笔者为此进行了跟踪分析。通过对环境调查、井深测量、抽水试验及水质检测等结果认为,此异常是井管老化、腐蚀、渗漏,浅层高矿化度水渗入井内引起的,与地震孕育、区域构造活动等无关。

Salt water layer is a kind of special aquifer in the coast region of north China plain. Observations and practices for many years indicate that the groundwater regime of salty water layer has strong earthquake reflecting capacity. Panzhuang well is a salty water observation well, the groundwater regime is normally stable and daily rangeability is less than 10 centimeter. For years this well has showed anomalies of water level obviously before earthquakes in Capital Region of China especially the Tangshan area. In May 2010, the abrupt increase anomaly of water level in this well was close to 3 meter. We need to scientificly determine that the anomaly is caused by other factors of interference or the earthquake preparation. Through the investigation and the analysis on the environment, well depth measurement, pumping tests and water quality testing, we conclude that the anomaly is caused by pipe aging, corrosion, leakage and shallow high salinity water infiltra- tion in the well, and it is irrelevant to the earthquake preparation or tectonic activity.