大地電磁法於溫泉地下水之探勘－以台中某地為例

Investigate the Geothermal Water by Using MT Technique -a Case Study in Taichung

游峻一(Chun-Yi Yu) ； 楊潔豪(Chieh-Hou Yang)

《健行學報》 35卷1期 (2015/01) Pp. 17-30

摘要

大地電磁法為一種頻率域的電磁波探勘技術，係應用自然界不同頻率的電磁波入射地下，地下深度不同的各地層因岩性及構造等不同，造成地表接收其不同之電磁感應，以此來區分地層特性，由於其測勘經濟及快速，對地下地層又具有良好的解析能力，被廣泛的應用於斷層描繪、地下水探測、探討環境變遷、劃分污染範圍、探礦調查等。近年來，因旅遊風氣盛行，對於溫泉地下水需求甚大，然而開發溫泉地下水成本非常高，如能事先進行調查，評估當地是否適合開發溫泉地下水，一方面減少鑿井失敗的風險，另一方面對於所需經費也可事先評估，本研究以大地電磁法於台中大坑某山區探測為例，測勘結果與鑽井的成果比對結果相符，印證大地電磁法於山區溫泉地下水調查確為一有效之方法。

關鍵字

大地電磁法 ； 頻率域 ； 探勘 ； 溫泉地下水 ； 鑽井

並列摘要

The magnetotelurics (MT) method is a frequency domain electromagnetic exploration technique. It is based on the electromagnetic responses of layers at different depth from an incident of natural electromagnetic waves with different frequencies. Then the characteristics of subsurface can be recognized. This technique has its economic and fast. In addition, the resolution of the subsurface is good. Therefore, it is widely used for identifying a fault, locating groundwater, mapping changes of a depositional environment, mapping of pollution zone and exploring a mineral deposit etc. In recent years, tourism is very popular. The geothermal water has great demanded. However, drilling a geothermal well is very expensive. If a site is being investigated prior and evaluated the suitable for the development of groundwater springs, then the risk of failure of drilling can be reduced, at the same time, prior assessment of funding can be figured out. For example, a case study of MT survey was carried in the Dakeng, Taichung; the final MT result was verified by the post drilling. It indicates that MT technique is suitable applied to the groundwater exploration in the mountainous area in Taiwan.

並列關鍵字

MT ； frequency domain ； exploration ； geothermal water ； drilling