Mapping of 3D Hydrogeological Framework of the Deccan Basalt Groundwater Systems Using AEM

The SkyTEM data provides a comprehensive three-dimensional picture of the subsurface. The low moment data ensured the high resolution mapping of the near surface and the high moment data to the deeper level. The dual moment AEM data provided high resolution mapping of subsurface from top to ∼ 250 m depths. The results revealed significant contrast between the B-G layers that has a resistivity range of 10–15 Ωm and generally has groundwater yields of 6–8 lps. It is also noted that the groundwater yield (> 6 lps) increases for deeper (<150 m) B-G contact.

The potential aquifer zones such as intertrappeans, fractures in vesicular basalts and Basalt-Gondwana contact are clearly mapped in the resistivity section. The regional fault (potential aquifer) which is abutting in the SW part with its orientation SE-NW is successfully delineated in the mean resistivity maps. The aquifer systems in basalts and Gondwanas and their extensions are also clearly demarcated on the 3D map using AEM data.