characters. In this diagram, three distinct fields
are recognized, such as evaporation dominance,
rainfall dominance and rock water interaction on
water chemistry. Gibb’s plots were created from
ratio I (for anion) Cl/(Cl + HCO 3 ) and ratio II
(for cation) Na/(Na + Ca) of the groundwater
samples which are plotted separately against the
respective values of TDS. Figure 14.7 indicates
that most of the groundwater samples fall under
evaporation zone and few samples are placed
under rock/water interaction field. Evaporation
process is not only a common phenomenon in
surface water but also in groundwater system
(Jankowski and Acworth 1997). The result
reveals that evaporation is the dominant process
due to dry and arid condition prevailing
throughout the region. Na/Cl ratio tends to be
constant when EC rises up to certain extent in the
non-mining areas.
14.1.4 Groundwater-Level
Fluctuation
Groundwater elevation is significant parameters
for monitoring the groundwater aquifer system.
The water table of an area is mainly controlled by
variations in groundwater recharge, discharge
Fig. 14.5 Ground Water
Quality Index (GWQI) map of
the study area
192
S. Selvakumar and N. Chandrasekar