Integration of geophysical, hydrogeological and geospatial analysis for
groundwater assessment in Chotanagpur Granite-Gneiss Complex, Ranchi
Abstract
Integrated study combining electrical resistivity tomography, geology,
hydrogeomorphology, and weighted overlay analysis of various surface and
subsurface thematic layers proved to be a very useful tool for
evaluating the heterogeneous hard aquifer systems for groundwater
assessment and development. A comprehensive study was carried out at
representative and varied geological settings viz., Chotanagpur
Granite-Gneiss Complex (CGGC), Ranchi has been accomplished from geology
and geophysical datasets. The electrical resistivity tomography results
revealed potential target zones at three sites in the study area up to a
maximum of 170 m depth with a large variation in aquifer resistivity
ranging from 80 to 800 Ω.m. These significant findings depicted a good
correlation and are validated with the lithology in the surrounding of
the resistivity tomography results. Nevertheless, the weighted overlay
technique act as an essential tool for spatial analysis and
interpretation of potential groundwater zones in the study area as well
as validated the geophysical depth models whereas in-depth study on
geology and hydrogeomorphology provides a detailed hydrogeological
scenario throughout the study area for the long-term sustainability of
the groundwater resources both at a local and in regional scale in the
typical hard rock aquifer system.