The effect of terrain topography on commonly used resistivity arrays

In this work a study of the effect of surface topographical variations on several dc resistivity arrays is presented. A 2.5-D finite-element modeling scheme is used to examine the performance of several arrays over buried features that exist below a range of different topographical terrain contexts, such as valleys, hills, and steep slopes. A mesh-generating algorithm allows a realistic representation of terrain topography. The results confirm that topographical variations can have a significant impact on the field resistivity data values for all resistivity arrays. Further, topographical variations can be treated flexibly using a realistic resistivity forward modeling process. Thus, topographic effects, to the degree they can be modeled, are predictable and should be taken into account when designing surveys and interpreting data.