議題內容

議題：地震地下水觀測站網系統年度成果發表 >> 投影片下載

講者：成大防災研究中心 賴文基副主任，葉永信工程師

大綱：


震前地下水文異常變化偵測及資料庫建置經驗分享

多年來世界各國的地震前兆研究一直嘗試於地震發生之前的孕育過程中，能在地殼表面或淺處地層中偵測到斷層活動相關的物理或化學變化。監測地下水文變化有潛力提供地震發生前斷層活動及地殼變形的訊息，因此本計畫將地下水文變化作為地震監測項目，以期發現有潛力的震前地下水異常變化型態。

藉由觀測系統與後端資料展示及分享系統，逐步將各項研究成果加以具體呈現及系統化，藉此俾利於長期資料之收集保存、分析研究與成果展現及資源分享，進而再擴大國內外相關研究機關之參與。

議題：A Preliminary Study of Ground Water Level Change due to Earthquake using Time-Frequency Analysis and Hilbert-Huang Transform >> 投影片下載

講者：逸奇科技總經理/史丹佛航太博士/王逸民

大綱：

Abnormal level change of ground water has been suggested as an indicator to earthquake precursor. But how to define and distinguish the abnormal signal still remains a challenge. In this study, we use high resolution time-frequency analysis including Hilbert-Huang Transform (HHT) to understand the behavior of ground water. Body tide, artificial pumping, and precipitation effects can be identified clearly in time-frequency plot and be separated via method of HHT. Two indicators from time-frequency plot are proposed as possible precursors to earthquake. One is related to abnormal inflow into ground water reservoir, and the other to tectonic plate intrusion and vibration. (data source: Central Weather Bureau and Water Resource Agency)

Figure:Time-frequency analysis of ground water signal of the station in Hwalien. The upper is the recorded raw data from Apr. 1st to Apr. 30th , 2006. Removing the tide effect results in signal shown in the middle plot. The spike at the end of the signal is the co-seismic effect. It appears as a vertical straight line In time-frequency-energy representation shown at the bottom. Parallel horizontal lines in the same plot suggest the existence of vibration taken place during the recorded period of time. The change of vibration mode as shown on Apr. 25th was followed by occurrence of near field earthquake.

議題: 地下水觀測網維護輔助系統介紹 >> 投影片下載

講者: 逸奇科技工程師/倪瑋傑

大綱:

源於經濟部水利署之兩年計畫「地下水觀測網執行成效及發展計畫」發展地下水觀測網維護輔助系統，系統連接水利署之歷史地下水水位資料庫，以視覺化展示各地下水分區觀測井建置位置，提供地下水水位歷線圖與三維地下水水位曲面圖等多種展示功能，並提供歷史水位異常檢定修正，水位資料匯出等功能。另外針對站井維護部份，開發了地質柱狀資料庫維護更新、試水資料庫建置、與井體攝影維護等功能，以利於地下水觀測網之資料維護與地下水水位資料庫之資料分析應用。