A comparative study of pseudo-dipole arrays and standard arrays based on the high-density DC resistivity method

High-density direct current resistivity surveys play a crucial role in characterizing aquifer structures and groundwater contamination. However, the necessity of using multiple electrode arrays to achieve comprehensive subsurface imaging significantly prolongs field data acquisition, posing challenges to efficient hydrological investigations. This study validates an efficient approach that employs a single pseudo-dipole array to derive comprehensive datasets equivalent to those obtained from multiple standard arrays (e.g., Wenner α, β, γ). The pseudo-dipole configuration, which utilizes fixed reference electrodes positioned at the line ends, demonstrates vertical resolution comparable to that of conventional dipole arrays, while offering superior lateral resolution in our analysis. Numerical modeling and analytical solutions for homogeneous half-space, vertical contact, and multi-anomaly models confirmed that the pseudo-dipole array exhibits enhanced sensitivity to subsurface anomalies. Numerical experiments demonstrate that high-resolution apparent resistivity pseudosections and reliable inversion models, derived from transformed pseudo-dipole data, can effectively identify hydrological units. This method provides a time-efficient solution for detailed aquifer mapping and contamination plume monitoring, thereby enhancing the utility of electrical resistivity tomography in water resource management.