Estimation of Groundwater Quality in Arid Region or Semiarid Region by Using Statistical Methods and Geographical Information System Technique

Table 6

Parameters used to classify groundwater.

Parameter	Range	The water’s quality	Total number of samples		(%)
			PRM	POM	PRM	POM
Ratio of sodium adsorption (in meql-1)	<10	Excellent	15	15	95	95
	10-20	Good	0	0	0	0
	20-28	Doubtful	0	0	0	0
	>28	Unsuitable	0	0	0	0
Kelly’s ratio (KR) is a mathematical formula (in meql-1)	<1	Suitable	12	16	62	82
	1-3	Marginal	4	2	22	14
	>3	Unsuitable	3	2	11	6
RSC stands for residual sodium carbonate (in meql-1)	<1.25	Safe	0	0	0	0
	1.25-2.25	Marginal	2	4	6	16
	>2.25	Unsuitable	20	18	96	85
PS stands for potential salinity (in meql-1)	<6	Excellent to good	7	6	32	25
	6-12	Good to injurious	7	7	32	32
	>12	Injurious to unsatisfactory	9	10	42	46
The permeability index (PI) is a measure of how permeable a material is (in meql-1)	>80	Excellent	20	20	95	90
	30-80	Good	2	2	6	6
	<30	Unsuitable	0	0	0	0
Sodium percentage (SP) is a measure of how much sodium is present in a given amount (in meql-1)	<25	Excellent	3	4	12	15
	25-45	Good	8	8	35	30
	45-65	Permissible	7	8	32	35
	65-85	Doubtful	6	4	25	16
	>85	Unsuitable	0	0	0	0
The magnesium ratio (MR) is a measure of how much magnesium is present in a given amount of (in meql-1)	<30	Suitable	7	6	45	20
	>30	Unsuitable	13	16	65	80
Corrosive ratio (CR)	>1.5	Eroding	4	2	15	6
	<1.5	Harmless	18	20	85	100
Index of water quality (WQI)	<45	Excellent	2	5	6	25
	45-95	Good	10	14	45	70
	95-190	Poor	9	4	45	20
	190-290	Very poor	3	0	12	0
	>290	Undesirable for drinking	0	0	0	0