Groundwater Potential Delineation Using Electrical Resistivity Tomography (ERT) in the Kohat Region, Khyber Pakhtunkhwa, Pakistan
Keywords:
Electrical Resistivity Tomography, groundwater potential, resistivity inversion, 3D resistivity modelAbstract
This study delineates groundwater-potential zones in the Kohat region of Khyber Pakhtunkhwa, Pakistan, using Electrical Resistivity Tomography (ERT) integrated with existing well information and GIS-based groundwater-potential mapping. Four north–south ERT profiles were acquired using 34 electrodes at 20 m spacing, giving a maximum profile length of 660 m. The data were processed and inverted to obtain two-dimensional resistivity sections, then the four profiles were integrated to construct a three-dimensional resistivity model in Voxler. Inverted resistivity range from approximately 5 to 750 Ω·m and show marked lateral and vertical heterogeneity. Low-to-moderate resistivity zones (approximately 10–110 Ω·m) occur mainly within the shallow 0–30 m interval and are interpreted as groundwater-potential zones, with responses consistent with unconsolidated to semi-consolidated materials and increased moisture content. Intermediate resistivity zones at approximately 30–80 m are interpreted as weathered or fractured material in selected parts of the profiles, whereas high-resistivity zones generally correspond to competent, relatively dry or low-permeability formations. The 3D model indicates spatially discontinuous conductive and structurally controlled zones, with comparatively favorable conditions in the northern and central parts of the surveyed area and less favorable conditions toward the west. Comparison with the published GIS/MIF groundwater-potential model and nearby well information indicates broad agreement between shallow ERT responses and reported groundwater occurrence. A candidate exploratory drilling target is retained near 560 m along Line 01; however, the ERT interpretation should be verified by lithological logging, water-level measurements, and pumping tests before groundwater development. The study demonstrates the value of integrating surface-based groundwater mapping with subsurface geophysical imaging for local-scale groundwater exploration in the Kohat region.
References
Ahmad, S., Kroon, D., Reijmer, J. J. G., Khan, S., Hersi, O. S., & Wadood, B. (2024). Paleogene carbonate ramp development in the Kohat Basin of northwestern Pakistan. Australian Journal of Earth Sciences, 71(2), 277–306. https://doi.org/10.1080/08120099.2023.2279062
Ahmad, S., Rigby, S., Kroon, D., Khan, S., & Haneef, M. (2011). Integrated Paleogene sequence stratigraphy of the Kohat Basin, northwest Pakistan. Proceedings of the SPE-PAPG Annual Technical Conference 2011, 81–92.
Ahmad, W., Liu, L., Guo, Z., Khalil, Y. S., Islam, N. U., & Islam, F. (2025). Lithological classification using ZY1-02D hyperspectral data by means of machine learning and deep learning methods in the Kohat–Pothohar Plateau, Khyber Pakhtunkhwa, Pakistan. Remote Sensing, 17(8), 1356.
Faheem, H., Khattak, Z., Islam, F., Ali, R., Khan, R., Khan, I., & Tag Eldin, E. (2023). Groundwater potential zone mapping using geographic information systems and multi-influencing factors: A case study of the Kohat District, Khyber Pakhtunkhwa. Frontiers in Earth Science, 11, 1097484.
Khair, S. M., Mushtaq, S., Culas, R. J., & Hafeez, M. (2012). Groundwater markets under water scarcity and declining watertable conditions: The upland Balochistan Region of Pakistan. Agricultural Systems, 107, 21–32.
Khan, E., Naseem, A. A., Khan, S., Wadood, B., Rehman, F., Saleem, M., Mehmood, M., Ahmad, W., Ahmed, Z., & Azeem, T. (2022). Facies analysis, sequence stratigraphy and diagenetic studies of the Jurassic carbonates of the Kohat Basin, Northwest Pakistan: Reservoir implications. Acta Geologica Sinica (English Edition), 96(5), 1673–1692. https://doi.org/10.1111/1755-6724.14938
Khan, M., Sayem, A. S. M., & Shah, M. (2018). Numerical groundwater flow modeling of Kohat basin: An example from Himalayan fold and thrust belt Pakistan. MAUSAM, 69(2), 263–276. https://doi.org/10.54302/mausam.v69i2.305
Konikow, L. F., & Kendy, E. (2005). Groundwater depletion: A global problem. Hydrogeology Journal, 13(1), 317–320. https://doi.org/10.1007/s10040-004-0411-8
Meissner, C. R., Jr., Master, J. M., Rashid, M. A., & Hussain, M. (1974). Stratigraphy of the Kohat Quadrangle, Pakistan (U.S. Geological Survey Professional Paper 716-D). U.S. Government Printing Office. https://doi.org/10.3133/pp716D
Nazir, J., Ali, M., Sarwar, A., Khan, S., Rehman, K., Fahim, B., & Iqbal, B. (2025). Delineation and validation of GIS-based groundwater potential zones under arid to semi-arid environment using multi-influence-factors approach. Geology, Ecology, and Landscapes, 9(4), 1194–1210. https://doi.org/10.1080/24749508.2024.2392382
Reynolds, J. M. (2011). An Introduction to Applied and Environmental Geophysics (2nd ed.). Wiley-Blackwell.
