Page 167 - AJWEP-22-6

Water quality of Bharatpur, Nepal

were further simplified. Eight groundwater quality 3.3.5.2. Conductivity versus TH
113
parameters were evaluated in this study. PCA/FA The regression line equation for the conductivity versus
identified three principal components that explained TH regression plot in Figure S1 is y = 0.762x + 0.226
2
nearly 81% of the total variation. Based on GWQI (maximum deviation = 0.107, r = 0.925). This high
2
results, approximately 13% of the samples were r value indicates an extremely strong positive linear
categorized as “awful” to “extremely poor,” while association. Thus, it can be concluded that there is a
87% were classified as “good.” A model incorporating strong correlation between conductivity and TH. The
turbidity, iron, electrical conductivity, manganese, TH, equation suggests that for every unit increase in TH,
and Cl as independent variables was proposed as a conductivity increases by 0.762 units. This relationship
−
more realistic predictor of GWQI, based on the MLR is consistent with the expected behavior, as higher TH,
2+
2+
analysis. Furthermore, our MLR model demonstrated typically due to dissolved ions, such as Ca and Mg ,
that turbidity, with the highest beta coefficient (0.820), leads to increased conductivity. The small maximum
was the most substantial contributor to groundwater deviation (0.107) further confirms the robustness of the
quality in the affected area. regression model in predicting conductivity based on TH.

3.3.5. Regression analysis 3.3.5.3. TH versus total dissolved solids
A simple linear regression analysis was conducted using The regression line equation for the TH versus TDS plot
SPSS software, with temperature as the dependent in Figure S2 is y = 0.447x + 0.555 (maximum deviation
2
variable and the other components as independent = 0.320, r = 0.700). This value indicates a strong and
variables. Among all the parameters considered, the statistically significant positive linear relationship. The
effects of total alkalinity, conductivity, TDS, PO , equation implies that for every unit increase in TH, TDS
3−
4
and TH were found to be significant at the standard increases by 0.447 units. This relationship is expected,
2+
2+
significance level (0.05). However, these parameters as TH, primarily caused by dissolved Ca and Mg ,
failed to sufficiently explain fluctuations in the dependent contributes to the overall TDS in water. The maximum
variable, as evidenced by the adjusted r values, which deviation of 0.320 indicates that while the regression
2
were observed to be moderate to very low in many model provides a reasonable fit to the data, other factors
may also influence TDS.
cases. The correlations between these parameter pairs
are graphically displayed in the regression charts below 3.3.5.4. TH versus free carbon dioxide
(Figure 16). The r value provides information on the The regression line equation y = 1.09x − 0.0849
2
goodness of fit, with values closer to 1 denoting a better (maximum deviation = 0.0931, r = 0.942) was obtained
2
fit, while the slope indicates the direction and strength by plotting TH against free CO , as shown in Figure S3.
2
of the relationship. The regression analysis revealed a strong positive linear
relationship, as indicated by the high coefficient of
3.3.5.1. Conductivity versus total dissolved solids determination (r = 0.942). This equation suggests
2
The regression line equation: y = 0.633x + 0.394 that for every unit increase in free CO , TH increases
(maximum deviation = 0.103, r = 0.880) was obtained by 1.09 units. This relationship is consistent with the
2
2
by plotting conductivity against TDS, as shown in expected behavior, as free CO in water can react with
Figure 16. The regression analysis revealed a strong, carbonate minerals (e.g., calcium carbonate) to form
2
statistically significant, positive linear relationship, HCO , which contributes to TH. The small maximum
−
3
as indicated by the high r value (0.880). This deviation (0.0931) further confirms the robustness of the
2
equation suggests that for every unit increase in TDS, regression model in predicting TH based on free CO .
conductivity increases by 0.633 units. This relationship 2
is consistent with the expected behavior, as TDS 3.3.5.5. TH versus ammonia
represents the total concentration of dissolved ions in The regression line equation y = 0.995x + 0.0231
water, and conductivity measures the water’s ability (maximum deviation = 0.115, r = 0.905) was obtained
2
to conduct electricity, 82-85 which is directly influenced by plotting TH against NH , as depicted in Figure S4.
3
by the presence of those ions. The small maximum The regression analysis revealed a strong positive linear
deviation (0.103) further confirms the robustness of relationship, indicated by the high r value (0.905). This
2
the regression model in predicting conductivity based equation suggests that for every unit increase in NH ,
3
on TDS. TH increases by 0.995 units. This relationship may

Volume 22 Issue 6 (2025) 161 doi: 10.36922/AJWEP025120083