Suo Kui, Zhao Mingdong, Jia Menghan, Liu Wenhui, Chen Shizhong, Zhao Guizhang
North China University of Water Resources and Electric Power, No. 136, Jinshui East Road, Jinshui District, Zhengzhou City, 450046, Henan Province, PR China.
Heliyon. 2024 Aug 3;10(15):e35709. doi: 10.1016/j.heliyon.2024.e35709. eCollection 2024 Aug 15.
Resistivity data has important applications in geophysical exploration, but the impact of electrode offsets on resistivity response characteristics remains unclear. This study aims to explore the influence of horizontal electrode offset angles and vertical offsets caused by topographical variations on the forward modeling of resistivity data. By analyzing experimental models with different measurement arrays, the paper revealed their influence laws on the buried depth of the target body and resistivity resolution. Utilizing tools like ZondRes3D, we conducted 3D resistivity forward modeling and analyzed the results in detail. It is found that horizontal electrode offsets lead to pseudo-anomalies in the apparent resistivity response, which is related to the offset angles and the number of electrodes. Under different conditions, the horizontal electrode offsets exhibit a "gradient variation" pattern. In addition, topographical variations can also cause distortions and offsets in the apparent resistivity curves and the locations of the anomaly response. Specifically, the measuring lines near the edge of the target bodies are more susceptible to these effects. Based on the comprehensive experimental results, we have drawn several conclusions regarding the impact of electrode offsets and topographical variations, including the effects of offset angles on the pseudo-anomalies, the anomalous response laws under different topographic conditions, as well as anomalous situations under specific angles. These findings provide crucial insights for interpreting resistivity data in geophysical exploration and addressing practical engineering problems, and offer guidance for optimizing measuring line layouts and post-processing terrain correction algorithms.
电阻率数据在地球物理勘探中具有重要应用，但电极偏移对电阻率响应特征的影响尚不清楚。本研究旨在探讨地形变化引起的水平电极偏移角度和垂直偏移对电阻率数据正演模拟的影响。通过分析不同测量阵列的实验模型，揭示了它们对目标体埋藏深度和电阻率分辨率的影响规律。利用ZondRes3D等工具进行了三维电阻率正演模拟并详细分析了结果。研究发现，水平电极偏移会导致视电阻率响应出现伪异常，这与偏移角度和电极数量有关。在不同条件下，水平电极偏移呈现出“梯度变化”模式。此外，地形变化还会导致视电阻率曲线和异常响应位置的畸变和偏移。具体而言，目标体边缘附近的测量线更容易受到这些影响。基于综合实验结果，得出了关于电极偏移和地形变化影响的若干结论，包括偏移角度对伪异常的影响、不同地形条件下的异常响应规律以及特定角度下的异常情况。这些发现为地球物理勘探中电阻率数据的解释和解决实际工程问题提供了关键见解，并为优化测量线布局和后处理地形校正算法提供了指导。
