LAUSR

The development of the Tongchuan city, Shaanxi, located in northwestern region of China is restricted by water resources. The application of direct current resistivity method and induced polarization (IP) sounding method are usually used to find urban groundwater. These methods, however, are not effective due to its complicated topography and geological conditions. The application practice shows that the audio magnetotelluric method (AMT) is of 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 structure features of the observation area are obvious. The main structure of the observation area is about 45° northeast by structural trend analysis. A shallow two-dimensional electrical profile of 1 km in Tongchuan City is obtained by a two-dimensional nonlinear conjugate gradient inversion.. Finally, combined with regional geological information, the geological structure characteristics reflected by the electrical profile were obtained with detailed the characteristics of water-rich structures in the area. The influence of the structure on the distribution of groundwater was analyzed and the water-rich areas were trapped. That contributes prospective development of Tongchuan city.