Sl. no.

Water quality indices

References

1

$\text{TotalHardness}\left({\text{asCaCO}}_3\right)=\left({\text{Ca}}^{2+}+{\text{Mg}}^{2+}\right)\times 50$

Sawyer & McCarty, 1967

2

$\text{Na\%}=\left(\left({\text{Na}}^{+}+{\text{K}}^{+}\right)\times 100\right)/\left({\text{Ca}}^{2+}+{\text{Mg}}^{2+}+{\text{Na}}^{+}+{\text{K}}^{+}\right)$

Wilcox, 1948

3

$\text{SAR}={\text{Na}}^{+}/\sqrt{{\text{Ca}}^{2+}+{\text{Mg}}^{2+}}$

Richards, 1954

4

$\text{RSC}=\left({\text{HCO}}_3^{-}+{\text{CO}}_3^{2-}\right)-\left({\text{Ca}}^{2+}+{\text{Mg}}^{2+}\right)$

Apha et al., 1998

5

$\text{KI}={\text{Na}}^{+}/\left({\text{Ca}}^{2+}+{\text{Mg}}^{2+}\right)$

Kelley, 1963

6

$\text{MR}=\left({\text{Mg}}^{2+}\times 100\right)/\left({\text{Ca}}^{2+}+{\text{Mg}}^{2+}\right)$

Paliwal, 1972

7

$\text{PI}=\left(\left({\text{Na}}^{+}+\sqrt{{\text{HCO}}_3^{-}}\right)\times 100\right)/\left({\text{Ca}}^{2+}+{\text{Mg}}^{2+}+{\text{Na}}^{+}\right)$

Doneen, 1964