Correlation analysis
Pearson’s correlation matrix is widely used to identify the role of each
water quality parameter and its impact on the deterioration of
groundwater chemistry. The value of “R” varied from -1 to +1, and it
indicates the positive value is a high correlation, and negative values
are less correlation with each other (Umarani et al., 2019, Wagh et al.,
2020, Yidana et al., 2018). In a study area, correlation coefficient
analysis (Table.7) and scatter matrix plot (Fig.15) are reveals that,
the pH has a negative correlation with EC, TDS, TH, Na, Ca, Mg, K Cl,
SO4, NO3 and F, and positive correlation with
CO32- (r2=0.31),
HCO3- (r2=0.11)
which indicates moderate correlation with each other parameters. The EC
has a high positive correlation with TDS (r2=1.00), TH
(r2=0.93), Ca2+(r2=0.88),
Mg2+(r2=0.85),
SO42-(r2=0.80) and
NO3-(r2=0.74) and
low positive correlate with
Na+(r2=0.17),
K+(r2=0.32),
HCO3-(r2=0.59) and
Cl-(r2=0.36). TDS has a positive
correlation with TH, Ca2+, Mg2+,
SO42- and
NO3- and negative correlation with
CO32- (r2=0.33). TH
has a high positive correlation with
Ca2+(r2=0.94),
Mg2+ (r2=0.92) and
SO42+(r2=0.83) and
negative correlation with CO32-(r2=0.29). It indicates the reverse ion exchange and
weathering process dominating the nature of groundwater. Since NO3-
positive correlate with Ca(r2=0.70) and Mg
(r2=0.69), it shows that agriculture activities highly
influence groundwater’s nature. SO42-has a high positive correlation with Mg (r2=0.86),
indicating anthropogenic influence.