Groundwater resources survey of tongchuan city using the audio magnetotelluric method
Tóm tắt
The development of Tongchuan City, Shaanxi Province, located in the northwestern region of China, is restricted by water resources. The direct current resistivity and induced polarization sounding methods are typically applied in finding urban groundwater. These methods, however, are not effective due to their complicated topography and geological conditions. The application practice shows that the audio magnetotelluric (AMT) method has a large depth of exploration, high work efficiency, and high lateral resolution. To investigate the distribution of groundwater resources, we deployed three audio-frequency magnetotelluric profiles in the city area. The impedance tensor information of AMT data is obtained using SSMT2000. AMT data dimension analysis reveals that the two-dimensional structural features of the observation area are obvious. The main structure of the observation area is about 45° northeast, as indicated by structural trend analysis. A shallow two-dimensional electrical profile of 1 km in Tongchuan City is obtained by two-dimensional nonlinear conjugate gradient inversion. Finally, combined with regional geological information, the geological structure characteristics reflected by the electrical profile were obtained along with the detailed characteristics of water-rich structures in the area. The influence of the structure on the groundwater distribution was analyzed, and the water-rich areas were identified. This work contributes to the prospective development of Tongchuan City.
Tài liệu tham khảo
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