Detection of unfavorable geological bodies based on the data of audio magnetotelluric sounding method: A case study of a water conservancy project in Tibet
As an economical and efficient geophysical method, audio magnetotelluric sounding method (AMT) has been widely used in water conservancy engineering investigations, but its implementation in high altitude area of Qinghai-Tibet Plateau is complicated. In this study, with a water conservancy project in Tibet as the research object, we used apparent resistivity pseudo section map, one and two-dimensional inversion imaging and forward modeling verification methods to analyze the main structural components of the shallow sedimentary layer, rock basement and water bearing fracture zone 1 km under the study area, based on the AMT data and other geological and geophysical data in this area. The results show that AMT has strong applicability and reliability in the investigation of water conservancy projects in Tibet with the advantages of finding the buried faults, water-rich areas and other unfavorable geological bodies. The discovered electrical anomalies herewith hold strong geological significance to the surveys of location and construction of water conservancy projects.