CSIR-NGRI

Electrical and Heliborne Geophysics

Electrical and Heliborne Geophysics (EHG) is one of the potential R&D group since the inception of CSIR-NGRI. The core research areas involve basic and applied science focusing to characterize the near surface mostly dealing with groundwater. Since the foundation of the institute groundwater is one of the thrust areas where number of methodologies using electrical (ground and borehole), electromagnetic, hydrological and geostatistical methods have been developed for groundwater exploration, assessment and management. A resistivity modeling lab was one of the early facilities established at the NGRI during 1965-66 leading to important basic contributions by way of new technique development such as new electrode arrays and their efficacy in the detection of deeper bodies, resolution and enhancement of response.

Two-electrode array was a landmark finding in this direction. The institute has introduced an original concept of depth of investigation (DOI) that measure of depth to the zone contributing maximum to the signal measured at the surface in the DC electrical method. These studies earned wide recognition to the Institute internationally.

This R&D group boasts a diverse array of scientist, technical and research scholars dedicated to the mapping, management, and conservation of groundwater resources. These professionals come from various fields such as geophysics, hydrogeology, environmental science, and groundwater modelling. The group, recently has developed core competency on advanced hydrogeophysics using integrated approach of heliborne, ground and borehole geophysics as well as hydrogeological studies for aquifer mapping and management.

Successful demonstration of pilot project has brought many new insights such as mapping of potential groundwater bedrock fracture network, tectonic pathways and associated aquifers in hard rocks, precise 3D distribution of sand and clay in alluvial settings, coastal salinity, concealed paleo channels, discovered a mega buried paleochannel near Prayagraj, Uttar Pradesh. The group has recently established a new tool viz., Electrical-field Vector Resistivity Imaging (EVRI) for hydrological applications in urban areas with considerably greater depth, and developing capability for handling of bigdata and its translation in hydro-geophysical models and parametrization.

Apart from geophysical surveys and hydrogeophysical modeling, estimation of groundwater fluxes, aquifer parameter estimation and characterization such as natural recharge, hydraulic conductivity and transmissivity, pollution studies, natural treatment of wastewater using wetland have been developed. Further, the group has been carrying long term study to monitor the hydrographs since 1991 in Maheshwaram watershed to understand the complexity of hardrock hydrodynamic and established experimental hydrological park at NGRI campus Chautuppal for controlled and new experiments.

The development at the pilot studies are further up-scaled and applied at larger areas in similar geological settings. The group is also involed in dedicated study of critical zone i.e. hydrogeological characteistics of vadose zone.

The group has been contributing to various national missions to provide solution addressing large scale societal problem of water starting from Rajiv Gandhi Drinking Water Mission to the ongoing a mega project funded by the Ministry of Jal Shakti, Govt. of India on high-resolution aquifer mapping and management in arid region of NW India covering 4 Lakh sq.km area in phases, where Phase-I covering 1 Lakh sq.km area in states of Haryana, Rajasthan and Gujarat is successfully completed and gearing for Phase-II. The Group has also contributed to Surat smart city, mapping of palrochannel and river aquifer linkages under Namami Gange, tunnel projects in Himalayan hills with Rail Vikash Nigam Ltd., and hills of Western Ghats with Konkan Rail Corporation Ltd. The group is also playing important role of expert advisory at several national and international committees of government and industries in devising policies and providing solutions related to groundwater. The group has been regularly involved in developing capacity building to the students, researchers and groundwater professionals under Skill India program. The EHG group is open to new challenges in the field of hydrogeophysics and research collaborations, nationally and internationally.