Hydrogeochemical and GIS Analysis of Groundwater Quality for Drinking and Irrigation Purposes in Kuzhithuraiyar Sub-Basin, Kanniyakumari District, Tamil Nadu, India

Table 3

Water quality index and irrigation suitability of the water samples of Kuzhithuraiyar sub-basin.

Parameter	Range	Water class	Samples in premonsoon	Samples in postmonsoon
Water quality index	0–25	Excellent	—	—
	25–50	Good	48	48
	50–75	Moderate	—	—
	75–100	Poor	—	—
	100	Very poor	—	—
Sodium adsorption ratio	<10	Excellent	48	—
	10–26	Good	—	—
	>26	Doubtful	—	—
RSC	<1.25	Good	48	—
	1.25–2.5	Doubtful	—	—
	>2.5	Unsuitable	—	—
Sodium percentage	<20%	Excellent	1	3
	20 to 40%	Good	10	11
	40 to 60%	Permissible	21	23
	60 to 80%	Doubtful	16	11
	>80%	Unsuitable	—	—
Kelly’s ratio	<1	Suitable	23	27
	>1	Unsuitable	25	21
Permeability index	>75%	Good	37	35
	25 to 75%	Doubtful	11	13
	<25%	Unsuitable	—	—
Magnesium hazard	>50	Unsuitable	19	21
	<50	Suitable	29	27
Potential salinity	>3	Unsuitable	9	6
	<3	Suitable	39	42