Indian Journal of Geo Marine Sciences Vol. 46 (05), May 2017, pp. 1052-1060 Study on suitability of groundwater for irrigation purpose in Parambikulam Aliyar project area, India Elangovan K & Rani R Department of Civil Engineering, PSG College of Technology, Coimbatore 641 004, India [E-Mail: [email protected] ; [email protected]] Received 01 June 2015 ; revised 19 June 2015 Forty samples were taken within the study area and analyzed for various physico-chemical parameters. Observed values of the Hydrochemical parameters of the samples were further analyzed for the groundwater quality assessment based on the Irrigation Standards. Suitability of groundwater was assessed for irrigation suitability based on the parameters pH, TDS, 2+ 2+ + + - 2- - - - 2- TH, PI , MR, KI, RSC , SAR, Na%, EC, Ca , Mg , Na , K , and like HCO3 , CO3 , Cl , NO2 +NO3 and SO4 . Karl Pearson‟s correlation method was used to find out the relationship between these variables. Major hydro chemical facies were identified using Piper trilinear diagram. Results revealed that there are significant positive and negative correlations between the variables. EC has significant positive correlations between Mg2+, Na+, Cl- and TDS. [Keywords: Groundwater, Quality, Hydro-chemical parameters, Multivariate Analysis, Irrigation] Introduction carried out to study the characteristics of hydro Global environment is changing chemical parameters to assess the quality of continuously due to unfavorable alterations of the ground water according to the irrigation standards surroundings wholly as a bye product of man‟s in Parambikulam Aliyar area. actions through direct or indirect effect of changes in energy pattern, radiation levels, chemical and Materials and Methods physical constitution of organisms1. Groundwater The study area of Parambikulam Aliyar is located is mainly used for drinking, irrigation and in Coimbatore District, Tamil Nadu, India industrial purpose. The dependability on between the latitudes of 10o 10‟ 00”N to 10o 57‟ groundwater has reached high in recent decades 20”N and the longitudes of 76o 43‟ 20”E to 77o due to reasons such as unreliable supplies from 12‟ 30”E (Figure-1) with an area of 2389sqkm. It the surface water due to vagaries of monsoon, consists of 8 interlinked reservoirs (6 at the hills increase in demand for domestic, agricultural and and 2 at plains). industrial purpose2. Understanding the aquifer hydraulic properties and hydro chemical characteristics of water is crucial for groundwater planning and management3. Assessment of groundwater quality status is important for the development of society and protection of environment. Chemical composition of groundwater is related to the solid product of rock weathering and changes with respect to time and space4. Therefore, the variation on the concentration levels of the different hydro geochemical constituents dissolved in water determines its usefulness for domestic, industrial and agricultural purposes5. Present study was INDIAN J. MAR. SCI., VOL .46, NO. 05, MAY 2017 1053 It is one of the interstate projects sharing water, according to the irrigation standards as per IS based on the agreement carried out between the 2296:1992. All the results were imported to SPSS two states of Tamil Nadu and Kerala6. In this 17 software for further multivariate analysis like area, the surface water is being supplied to only Maximum (Max), Minimum (Min), Mean, 50% of the command area in a year. In alternate Median, Mode, Range, Standard deviation (SD) to the surface water, the groundwater utilization is and Correlation coefficient (r). Correlation more during non-supply period. Hence it is analysis is a bivariate method that describes the necessary to evaluate the groundwater quality due degree of relationship between two variables 9. In to overexploitation of groundwater. This area is order to confirm the relationship among the covered by denudation, fluvial landforms and parameters Karl Pearson‟s correlation method was structural hills –Anamalai hills at the southern used. The Correlation coefficient „r‟ is calculated part. Rainfall and temperature ranges from 1591 by the formula, o 7 to 4364 mm and 13.78 to 35.65 C respectively . N xy ( x)( y) The depth of well within the study area ranges r from 5 to 25m and average thickness of weathered [N x2 ( x)2 ][N y2( y)2 ] mantle is 10m. Parambikulam and Aliyar river basin comprises mainly of crystalline rocks of Archaean Where, age. Charnokites form the major rock type of the basin followed by the granites, granitic gneisses, N = No of Pairs of Scores dunites, limestones, quartzite basic and ultra basic intrusive of pegmaties and quaternery veins. xy = Sum of the products of paired Charnockites and associated migmatites occupy a scores major part of the area. The Anamalai hill ranges are composed of charnockites and their x = Sum of x scores magmatised equivalents. y = Sum of y scores Granites intruded into the older gneisses and charnockites, and have undergone x 2 =sum of squared x metamorphism and metasomatism. They occupy mostly small mounds or linear domes in the area. Hornblende–biotite gneisses occupy the central y 2 =Sum of squared y scores and northern portion of the basin area. Intrusions The sign of correlation coefficient of pegmatites and quartz veins are observed all determines whether the correlation is positive or over the area, traversing the country rock in all negative. The magnitude of correlation coefficient directions. Extensive cover of laterite occurs over determines the strength of the correlation. the western part of the area. Thickness of laterites According to Evans methodology (1985) seldom exceeds 15m. correlation strength was categorized as very weak Within the study area totally 40 (0.00-0.19), weak (0.20-0.39), moderate (0.40- groundwater samples were collected during the 0.59), strong (0.60-0.79) and very strong (0.80- February 2012 using clear acid washed polythene 1.00). bottles and analysis were done using standard Results and Discussion procedures8. The samples were analyzed for the following parameters like pH, Total dissolved Groundwater quality is an important solids (TDS), Total Hardness (TH), Permeability parameter in determining its suitability for Index (PI), Magnesium Ratio (MR), Kelly‟s Index particular use such as drinking, domestic, (KI), Sodium Percent (Na%), Electrical agricultural and industrial purposes. Irrigation Conductivity (EC), Sodium Adsorption Ratio water quality is important for successful crop (SAR), Residual Sodium Carbonate (RSC), production. Poor quality of the irrigation water cations like Calcium (Ca2+), Magnesium (Mg2+), + + may affect crop yields and soil physical Sodium (Na ), Potassium (K ) and anions like 10 - 2- conditions . Statistical measures of the chemical Bicarbonate (HCO3 ), Carbonate (CO3 ), Chloride - - - parameters were analyzed for the 40 groundwater (Cl ), Nitrate & Nitrite (NO2 &NO3 ) and Sulphate 2- samples (Table 1). (SO4 ). Suitable parameters were evaluated 1054 ELANGOVAN et al : SUITABILITY OF GROUNDWATER FOR IRRIGATION Table-1 Statistical Parameters of physical and chemical parameters of Groundwater samples in the study area No Parameters Min Max Mean Median Mode SD Range 1. EC 470.00 6030.00 1448.75 1040.00 740.00 1087.59 5560.00 2. pH 7.80 9.20 8.42 8.40 8.60 0.33 1.40 3. TDS 265.00 3327.00 846.45 626.00 265.00 652.13 3062.00 4. TH 60.00 1750.00 418.63 275.00 195.00 342.63 1690.00 5. PI 20.10 96.58 58.90 59.69 N/A 16.02 76.48 6. MR 7.25 78.75 46.22 47.11 N/A 16.21 71.50 7. KI 0.20 8.11 1.41 0.98 N/A 1.38 7.90 8. Na% 10.98 82.92 40.75 39.24 10.98 15.04 71.94 9. SAR 0.64 9.97 3.11 2.45 0.64 2.02 9.33 10. RSC 0.01 3.43 0.94 0.78 0.15 0.82 3.41 11. Ca2+ 12.00 328.00 67.80 42.00 38.00 62.43 316.00 12. Mg2+ 0.70 328.00 60.62 38.88 39.00 60.58 321.00 13. Na+ 30.00 506.00 136.65 102.50 74.00 107.74 476.00 14. K+ 1.00 266.00 25.53 9.50 8.00 47.32 265.00 - 15. HCO3 85.00 464.00 223.42 197.06 159.00 101.59 379.00 2- 16. CO3 0.00 66.00 18.52 15.00 18.00 17.64 66.00 17. Cl- 35.00 1914.00 282.78 129.50 60.00 357.67 1879.00 - - 18. NO2 +NO3 1.00 84.00 13.35 6.00 2.00 15.79 83.00 2- 19. SO4 10.00 1104.00 80.35 34.00 29.00 171.96 1094.00 20. F- 0.03 1.73 0.69 0.76 12.00 0.45 1.70 EC is a measurement of total salts can be attributed to decrease in the water volume dissolved in samples, the most significant water and increase in rate of evaporation of water11. quality standard on crop productivity. Results The concentrations of Ca2+, Mg 2+, K+ and Na+ revealed that EC value ranges from 470 to ranged from 12 to 328, 0.70 to 328, 1 to 266 and 6030µs/cm with a mean value of 1448.75µs/cm. 30 to 506 mg/l with mean values of 67.8, 60.62, The primary effect of high EC water on crop 25.53 and 136.65 mg/l, respectively. The - productivity was the failure of the plant to concentrations of the anions indicate that HCO3 2- - 2- + , - compete with ions in the soil solution for water. ,CO3 , Cl , SO4 and NO2 NO3 ranged from 85 The higher the EC, the lesser the water available to 464,0 to 66, 35 to 1914, 10 to 1104 and 1 to 84 to plants, even though the soil may show wet, mg/l with mean values of 223.42,18.52, 282.78, because plants can only transpire "pure" water; 80.35 and 13.35 mg/l, respectively.