Dynamical Analysis of Anomaly Behavior for Seismic Groundwater Level

• Main Authors: Wei-Chia Chen, 陳暐家
• Other Authors: Shu - Chen Lin
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/69033155534879631487

碩士 === 立德管理學院 === 資源環境研究所 === 91 === Taiwan is due to the characteristic of the geographic location and lies to the circum-pacific seismic zone. The frequency of seismic activity is high and the earthquake event usually takes place. To decrease the disaster loss of earthquake, the mechanism and process of earthquake need to be studied deeply. The variation of groundwater level anomaly is closely related to the earthquake, thus, it is essential to establish the anomaly pattern of each well. The basics provides for pattern identification of groundwater level anomaly prior to the earthquake. The research district is focused on the Choshui river alluvial fan and the earthquakes on September 21 of 1999 and March 31 of 2002 are used for case studies. The paper discusses the anomaly pattern of groundwater level by the heavy earthquake. Many cases show that the anomaly pattern of seismic groundwater level is so complicated and multiplex. The anomaly of groundwater level includes the earthquake, rain, tide, air pressure, factitiousness factor, and so on. There is the possibility on the reappearance of anomaly pattern in the same well. The statistics of anomaly pattern of groundwater level from two earthquakes are addressed and several typical cases are used to quantify the anomaly pattern by the intervention analysis model. The results show that the step-change and the surge-flush can obtain the specific pattern of intervention model. Besides, the impact and extent of the groundwater level variation of observation wells in the vicinity of hypocenter can be realized. When the time point of anomaly is detected, the anomaly caused by earthquake can be further confirmed. If the anomaly of groundwater level can be detected before the occurrence of earthquake, it provides a reference for prediction. We expect that the proposed method can be as an index for anomaly classification and verification for the anomaly behavior of groundwater level.