Application of airborne and ground geophysics to unravel the hydrogeological complexity of the Deccan basalts in central India

• Published in: Hydrogeology journal Vol. 30; no. 7; pp. 2097 - 2116
• Main Authors: Sonkamble, Sahebrao, Chandra, Subash, Pujari, Paras R.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.11.2022; Springer Nature B.V
• Subjects: Anomalies; Aquatic Pollution; Aquifer testing; Aquifers; Basalt; Complexity; Drilling; Earth and Environmental Science; Earth Sciences; Electric contacts; Electrical resistivity; Electromagnetic soundings; Geology; Geophysics; Geophysics/Geodesy; Gondwana; Groundwater; Groundwater management; Helicopters; Hydrogeology; Hydrology/Water Resources; Lava; Lava flows; Lithology; Logging; Pumping; Pumping tests; Soundings; Surveys; Tomography; Transmissivity; Waste Water Technology; Water Management; Water Pollution Control; Water Quality/Water Pollution; India; Groundwater monitoring; Lineaments; Geophysical methods; India
• ISSN: 1431-2174; 1435-0157
• DOI: 10.1007/s10040-022-02503-7

Groundwater occurrence in continental flood basalt, where multiple lava flows separated by intertrappean and irregular patterns of lineaments govern the regional hydro-dynamics, is poorly understood. This necessitates a high-resolution hydrogeophysical investigation to devise an effective groundwater management plan. To enhance the knowledge and unravel the hydrogeological complexity of such systems, an integrated hydrogeophysical investigation consisting of local-scale vertical electrical soundings, ground-based transient electromagnetic soundings, relatively large-scale electrical resistivity tomography (ERT) and helicopter-borne transient electromagnetic (H-TEM) surveys was carried out in an area of the Deccan Traps (372 km 2 ) near Nagpur, central India. A 14.4-km-long and almost continuous profile of ERT was conducted, with special attention to the lateral discontinuity, which was compared with the H-TEM data. The results from these studies were further supported and validated by drilling of exploratory wells at select locations, geophysical logging and pumping tests. Integration of the results successfully provided a geophysical characterization of the basalts, to develop a consistent lithological model that was finally transformed into hydrogeological sections. The pumping test (exploratory wells) derived aquifer transmissivity data that complemented the anomalies of the electrical parameters. Furthermore, the hydrogeological observations revealed that the groundwater yield is strongly correlated ( R 2 = 0.78) with the depth to the Basalt-Gondwana contact.