Investigation of the line arrangement of 2D resistivity surveys for 3D inversion
Investigation of the line arrangement of 2D resistivity surveys for 3D inversion
复制标题
3D反演2D电阻率测量线路布置研究
DOI：
10.1071/eg17019
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
D. Shoda
中科院分区：
文献类型：
--
作者：
Keisuke Inoue;H. Nakazato;M. Takeuchi;Yoshihiro Sugimoto;H. Kim;Hiroshi Yoshisako;Michiaki Konno;D. Shoda
我们已经进行了数值和现场实验，以研究电极配置和线布局的适用性，通常用于二维（2D）电阻率调查三维反演。我们研究了三种电极配置和两种类型的线的安排，在一个均匀的半空间中的导电体的16个电阻率模型。数值实验结果表明，平行线排列是有效的识别导电体的近似位置。正交线排列对于识别线交点附近的目标体是最佳的。因此，我们建议，平行线是有用的，以突出特别感兴趣的领域，进一步详细的工作与相交线可以进行。在野外试验中，在有回填坑的壤土层上测量了二维电阻率数据。从平行线数据得到的重建电阻率图像显示了回填坑附近的低电阻率部分。当在平行线上增加一条正交线时，新估计的回填坑位置与实际位置吻合良好。在进一步的现场应用中，我们在淡路岛的野岛断层区收集了几个二维电阻率数据集。这些数据集的3D反演提供了对应于地质结构的电阻率分布。特别是，野岛断层被成像为低电阻率带的西边界，只有两个正交线。我们已经进行了数值和现场实验，以研究电极配置和线布局的适用性，通常用于2D电阻率测量到3D反演。我们建议，平行线是有用的，以突出特别感兴趣的领域，进一步详细的工作与交叉线可以进行。
We have conducted numerical and field experiments to investigate the applicability of electrode configurations and line layouts commonly used for two-dimensional (2D) resistivity surveys to 3D inversion. We examined three kinds of electrode configurations and two types of line arrangements, for 16 resistivity models of a conductive body in a homogeneous half-space. The results of the numerical experiment revealed that the parallel-line arrangement was effective in identifying the approximate location of the conductive body. The orthogonal-line arrangement was optimal for identifying a target body near the line intersection. As a result, we propose that parallel lines are useful to highlight areas of particular interest where further detailed work with an intersecting line could be carried out. In the field experiment, 2D resistivity data were measured on a loam layer with a backfilled pit. The reconstructed resistivity image derived from parallel-line data showed a low-resistivity portion near the backfilled pit. When an orthogonal line was added to the parallel lines, the newly estimated location of the backfilled pit coincided well with the actual location. In a further field application, we collected several 2D resistivity datasets in the Nojima Fault area in Awaji Island. The 3D inversion of these datasets provided a resistivity distribution corresponding to the geological structure. In particular, the Nojima Fault was imaged as the western boundary of a low-resistivity belt, from only two orthogonal lines. We have conducted numerical and field experiments to investigate the applicability of electrode configurations and line layouts commonly used for 2D resistivity surveys to 3D inversion. We propose that parallel lines are useful to highlight areas of particular interest where further detailed work with an intersecting line could be carried out.