| Abstract Submission No. | ABS-3.1-0196 |
| Title of Abstract | Hydrogeophysical Investigation Using Electrical Resistivity Tomography (ERT) for Aquifer Characterization and Groundwater Quality Evaluation: A Case Study from Granitic Terrain |
| Authors | Shekhar More*, Ratnakar Dhakate |
| Organisation | CSIR-National Geophysical Research Institute |
| Address | CSIR-NGRI Hyderabad, Telangana, India Pincode: 500007 E-mail: shekharmore4444@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | Electrical Resistivity Tomography (ERT) is a reliable geophysical tool for investigating subsurface hydrogeological conditions, offering high-resolution imaging of lithological variations, aquifer geometry, and contamination. In this study, ERT surveys were conducted in a granitic terrain to evaluate groundwater resources and to delineate contamination zones. The objectives were: (i) groundwater exploration, through mapping of potential aquifer horizons, and (ii) contamination assessment, by identifying very low-resistivity signatures associated with polluted zones. The study employed a multi-electrode resistivity system with a Wenner-Schlumberger configuration, enabling both vertical and lateral resolution of subsurface resistivity, which provided cross-sections up to a depth of ~45 m. The results revealed significant spatial variability in resistivity values, reflecting the heterogeneous nature of the fractured granitic aquifer system. Zones of moderate resistivity (50 - 400 Ωm) were interpreted as water-bearing fractured horizons, while very low resistivity anomalies (<10 Ωm) indicated possible contamination. Correlation with the hydrochemical analysis confirmed that areas showing lower resistivity were consistent with higher concentrations of Total Dissolved Solids (TDS) map of the study area, validating the capability of ERT in detecting contaminated zones. Furthermore, resistivity contrasts highlighted the presence of structurally controlled fracture networks, which play an important role in groundwater movement and storage in hard rock terrains. The study demonstrates that ERT is an effective non-invasive method for groundwater exploration and also a powerful tool for contamination mapping when integrated with geochemical data. Such integrated hydrogeophysical approaches are crucial for developing sustainable groundwater management strategies in regions affected by contamination and limited water availability. |
| Keywords | Hydrogeophysics, Groundwater Exploration, Gorundwater Contamination, Aquifer Characterization |