In hard rock terrain, fractured aquifers comprise the major source
of groundwater availability where the phreatic aquifer is de-saturated. It is
essential to understand the interconnectivity between phreatic aquifer and deep
fractured aquifer, for better water management strategy. Identification of
fracture zones in hard rock terrain and potential groundwater source
delineation had been a perennial problem in hydrology in the recent past. In
concurrence to this, understanding the groundwater flow through fracture system
has also been a challenge to hydrologists and geophysicists. The purpose of
this paper is to highlight the study executed over a small watershed area, in a
granite terrain, wherein an attempt was made to delineate and map the fractured
aquifer using numerical (factor) analysis of the conventional vertical
electrical sounding (VES) data. Delineation of fracture zones at depths and
mapping their geometry were obscure due to limitations in 1D interpretation of
VES data through curve matching technique. Factor analysis for the same VES
data was carried out and as a result, fractured granite aquifer was deciphered.
Also, based on the factor analysis, a fault was deciphered in the study area
bifurcating the fractured aquifer into two segments which was later confirmed
based on satellite photo data and 2D resistivity imaging survey. This numerical
approach of resistivity data interpretation in concatenation with resistivity
imaging or other techniques would prove to be an effective tool in groundwater
exploration.
Author(s) Details:
Rolland
Andrade
Central Water & Power Research Station, Pune-24, India.
Please see the book here:
https://doi.org/10.9734/bpi/eieges/v6/8128A
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