In what could lead to providing a solution to India’s water scarcity problem, the Council of Scientific & Industrial Research (CSIR) is likely to start a helicopter-based electromagnetic survey to identify groundwater points, map structures, and measure salinity and contamination among others.
CSIR-National Geophysical Research Institute (NGRI), under the Ministry of Earth Science, has already carried out a heliborne survey in different hydrogeological terrains in Rajasthan (Dausa and Jaisalmer), Maharashtra (Nagpur), Karnataka (Tumkur), Tamil Nadu (Cuddalore) and Bihar (Patna) covering around 3,000 km of area.
“The results of the Rs25-crore project which was carried out at the initiative of the Ministry of Water Resources were encouraging. We have submitted the report to the Ministry,” N Purnachandra Rao, chief scientist at NGRI, told The Pioneer recently.
Rao said that they were waiting for the approval from the Centre to kick-off the mega survey across the country that would entail investment of around Rs12,000 crore over the next ten years.
So far, in India, airborne geophysical surveys have been conducted for mineral prospecting and geological mapping.
The scientist said that the water mapping of all the aquifers beneath the earth will help measure water yield, depth of the water to ensure its efficient usage and, contamination level which would in turn help the Government take preventive measures accordingly.
“Once we have the water map, we can prepare 3D map structure to show up to 300 metre beneath the surface,” he added.
Talking about the process of conducting the survey, he said that a metal coil from the helicopter is hanged down and using the electromagnetic signatures scientists can make out if there is groundwater-if current sails through, it indicates presence of water.
Girish Sahni, director general CSIR, called it the best technology in the world to map aquifers and that it also can help find spots and sources of contamination in groundwater. Moreover, it is time saving. This is for the first time in the country that an aquifer mapping in which Heliborne survey has been taken up for groundwater investigations, he added.
NGRI, a constituent laboratory of CSIR, was established in 1961 with the mission to carry out research in multidisciplinary areas of earth sciences. The Institute plays a pivotal role in the exploration of hydrocarbons, mineral and groundwater resources in addition to studies in engineering geophysics and seismology among others.