. 2023 Sep 26;9(10):e20431. doi: 10.1016/j.heliyon.2023.e20431

Table 6.

Pearson's correlation coefficient of EWQI with other water quality parameters in pre-monsoon season, in the study area- Alappad Coast, Kollam, Kerala, India.

	EWQI	pH	EC	Turbidity	TDS	DO	BOD	TA	TH	Cl⁻	Iron	SO₄^2-	NO₃⁻	Na⁺	K⁺	Ca²⁺
pH	0.32
EC	0.82^a	0.21
Turbidity	−0.30	0.14	−0.19
TDS	0.83^a	0.20	0.99^b	−0.19
DO	0.37	0.60^a	0.25	−0.29	0.23
BOD	−0.15	0.31	−0.02	0.37	−0.02	0.07
TA	−0.18	0.01	−0.16	0.27	−0.14	−0.56	0.45
TH	0.44	0.31	−0.13	−0.23	−0.12	0.21	−0.26	0.07
Cl⁻	0.82^a	0.20	0.99^b	−0.17	0.98^b	0.29	−0.05	−0.26	−0.15
Iron	−0.14	−0.45	−0.27	0.11	−0.27	−0.14	0.11	−0.19	−0.06	−0.22
SO₄²⁻	0.53^a	0.14	0.62^a	−0.35	0.64^a	0.29	−0.08	−0.10	0.00	0.54^a	−0.34
NO₃⁻	−0.17	−0.11	−0.09	0.51^a	−0.08	−0.70	0.23	0.63^a	−0.11	−0.13	0.15	−0.22
Na⁺	0.82^a	0.20	0.99^b	−0.18	0.99^b	0.27	−0.05	−0.23	−0.14	0.99^b	−0.24	0.53^a	−0.12
K⁺	0.77^a	0.14	0.91^b	−0.08	0.92^b	0.09	0.17	0.04	−0.09	0.88^b	−0.15	0.51^a	−0.04	0.89^b
Ca²⁺	0.40	0.32	−0.15	−0.19	−0.14	0.20	−0.24	0.11	0.99^b	−0.18	−0.09	0.06	−0.08	−0.17	−0.12
Mg²⁺	0.47	0.29	−0.10	−0.26	−0.09	0.23	−0.27	0.03	0.99^b	−0.10	−0.03	−0.07	−0.15	−0.09	−0.05	0.96^b

Correlation is significant at the 0.05 level (2- tailed), TH-total hardness, TA-total alkalinity.

Correlation is significant at the 0.01 level (2-tailed).