A Systematic Study of Topography Effect of ERT Based on 3-D Modeling and Inversion

作者：Lu De Bao^*; Zhou Qi You; Junejo S A; Xiao An Lin

来源：Pure and Applied Geophysics, 2015, 172(6): 1531-1546.

DOI：10.1007/s00024-014-1015-4

• Unstructured grid
• 3-D modeling and inversion
• ERT
• apparent resistivity features
• topography effect

In this study, a quick method using a digital elevation model (DEM) to obtain real terrain points for generating tetrahedral mesh has been developed, based on TetGen. Then three-dimensional (3-D) forward modeling and inversion, based on the patching method of electrical resistivity tomography (ERT) and which have been compared favorably with those obtained using other software, were used to study topography effect. Asystematic research of apparent resistivity features of different topographies with pole-pole array and Wenner array has been conducted in this study. Based on that, the solutions for removing topography effect are given to the two-dimensional (2-D) survey and the 3-D survey, respectively. Comparing to the inversion result, the solution for the 2-D survey can effectively remove topography influence. A 3-D inversion algorithm incorporating topography is proposed at the same time. Two synthetic models incorporating real topography with fault and ellipse anomalies were created to test the 3-D inversion algorithm, and the results show that the relative image error is less than 30 % and the correlation coefficient is more than 90 %.

• 出版日期2015-6
• 单位南京大学