International Journal of Civil Engineering and Technology (IJCIET) Volume 9, Issue 4, April 2018, pp. 372–381, Article ID: IJCIET_09_04_041 Available online at http://iaeme.com/Home/issue/IJCIET?Volume=9&Issue=4 ISSN Print: 0976-6308 and ISSN Online: 0976-6316 © IAEME Publication Scopus Indexed STATISTICAL INVESTIGATION OF GROUND WATER QUALITY ACROSS COOVUM WATERSHED Thanga Gurusamy.B, Ilango.T, Soundarya.M.K Assistant Professor, Department of Civil Engineering, VELS Institute of Science, Technology and Advanced Studies, (VISTAS) Chennai Paul Abbinesh.L.S, Ram Kumar.R, Janagar.N Student, Department of Civil Engineering, VELS Institute of Science, Technology and Advanced Studies, (VISTAS) Chennai ABSTRACT This paper investigate about the spatial variation of ground water quality across Chennai-Coovum watershed during the pre monsoon and pre 2015 flood season and compared with that of post monsoon and post 2015 flood season. Only chemical water quality parameters have been considered for this analysis. Basic statistical methods have been used to convert the observed data into useful information. This analysis is based on the data that has been made available to the public by Water Resources Department, Chennai Tamil Nadu. Both summary statistics analysis and Correlation based analysis has been carried out and the result have been presented in graphical and tabular form. SPSS software has been used to perform Correlation Coefficient analysis and other Measures of Dispersion and Measures of Central Tendency used to describe the water quality spatial distribution characteristics. Analysis of ratio of pre flood water quality to that of post flood water quality has been performed. Three locations such as Pudupet, Thirumazhisai, and Mugappair west have reported high flood sensitivity for most of the chemical water quality parameters. The ground water quality near Vepery and Chepauk hostel location are consistently not suitable for drinking purposes without proper treatment. Total Dissolved Solids (TDS) and Electrical conductivity (EC) are proving very good correlation strength with others such as Ca, Mg, Na, k and Cl. But some of the parameters such as PH, NO3, SO4, CO3, F and HCO3 do not show correlation strength with other parameters. Negative skewness has been reported only by PH parameter and the distribution of HCO3 is having zero skewness and similar to that of Normal distribution. Many parameters including TDS, Hardness and Fluorides proved to have Positive skewness and leptokurtic distribution. Keywords: Ground water quality, spatial distribution Analysis, Statistical methods, Correlation coefficient. http://iaeme.com/Home/journal/IJCIET 372 [email protected] Statistical Investigation of Ground Water Quality Across Coovum Watershed Cite this Article: Thanga Gurusamy.B, Ilango.T, Soundarya.M.K, Paul Abbinesh.L.S, Ram Kumar.R and Janagar.N, Statistical Investigation of Ground Water Quality Across Coovum Watershed, International Journal of Civil Engineering and Technology, 9(4), 2018, pp. 372–381. http://iaeme.com/Home/issue/IJCIET?Volume=9&Issue=4 1. INTRODUCTION The earth consists of atmosphere, lithosphere and hydrosphere. Life sustaining resources are available on all these three components of earth. The hydrosphere includes the oceans, streams, lakes and ground water resources that interflow with the surface water. The lithosphere covers the core of the earth. The atmosphere is containing a mixture of gases extending outward from the earth surface. The biosphere has received and assimilated the wastes generated by plants and animals. [1] Water quality in the intermediate stage between precipitation and evaporation will affect the Human use of water. The impurities present in the water may be in suspended, colloidal and dissolved form. Metcalf (1979)[2] has classified these impurities such that if the impurity particles size is above 1µm then it is called as Suspended impurities and if it is below 0.001 µm then it is dissolved impurities and in between 0.001 µm and 1µm is called as colloidal particles. Water pollution has been defined as the presence of impurities in such a quantity so as to impair the use of water for a stated purpose. The BUREAU OF INDIAN STANDARDS (BIS) has given water quality specifications for drinking use of water using the IS code 10500:2012. [3] These impurities have been classified as Physical, chemical and biological. Water resources management at all levels from upper stage National and State levels to lower stage local municipality level involves the task of monitoring the existing quantity and quality of water resources. This is because the objectives of this water resources department is to supply necessary amount of water with acceptable quality at the demanded point of time and space to satisfy the domestic, agricultural and industrial water requirements of the society. The monitoring involves the tasks of data collection and converting the data into useful information for decision making purposes such that the management process will get optimized. This research work involves the analysis of data collected by the water resources department to get useful information with the use of Statistical methods. The result presented in graphical and tabular form has been discussed. 2. LITERATURE REVIEW The importance of Ground water in both quantitative and qualitative perspectives has been discussed by Ayibatele (1992) [4] at world as well as local levels. The typical ground water quality of samples collected from tube wells and open wells has been discussed using basic methods by Mishra (2002) [5] and has been illustrated along with sources of pollutants. Garg (1990) [6] had presented the statistical based correlation analysis of ground water quality for the Roorkee city in the North Indian region. Shah (2007) [7] had reported the statistical based analysis for the ground water quality and other physiochemical parameters for area located in the Gujarat state. Sarkar (2006) [8] had presented the spatial variation of fluoride concentration in the ground water using statistical based correlation and regression methods. Shihab (1993) [9] had reported the application multivariate method for the analysis and interpretation of water quality data monitored for the Saddam reservoir. Pantelić (2012) [10] had used statistical based methods for the analysis of water quality parameters in the canal and the spatial distribution of water quality along the length of the canal had been discussed. http://iaeme.com/Home/journal/IJCIET 373 [email protected] Thanga Gurusamy.B, Ilango.T, Soundarya.M.K, Paul Abbinesh.L.S, Ram Kumar.R and Janagar.N Pollution of ground water resources due to infiltration of polluted water from Cooum River is has been investigated and reported by CGWD annual report. [11] Application of Statistical based methods in the area of water resources had been discussed by Helsel (2002). [12] Evaluation of the ground water quality based on the statistical methods had been performed by Singh (2006) [13] in the area of Northern Indo-Gangetic Alluvium Region. APHA, Washington (1998) [14] has reported the contamination of ground water quality from solid waste disposal system. Assessment of ground water quality had been carried out and reported by Hong (1999) [15] which involves the use of geographical information system to analyse the spatial variation of ground water quality. 3. STUDY AREA Coovum Watershed is geographically bounded between latitudes 12.9° N to 13.12° N and longitudes 79.6° E to 80.3° E. and having total catchment area is 400sq.km. Location of confluence with Bay of Bengal for this is Coovum mouth near Napier Bridge. The total length of this Coovum river is about is 72km and out of this, the length in the Chennai city limit is 18km, whereas the length in the Chennai Metropolitan Area (CMA) limit the length is 40 km.The origin of Coovum river is from the Coovum tank in the Thiruvallur district, which in turn receives water by the diversion from the Kesavaram anicut located across the Kosasthalaiyar river near Thakkolam. The upper catchment of Coovum River is primarily rural and it is constrained by the channels when it passes through Chennai city.The Ground water quality along Coovum river is highly polluted by the drainage networks of the Chennai city. The Coovum watershed contains the central Chennai area and typical bed width of Coovum River is in between 40m to 120m. The Figure 3.1 shows the location of Coovum watershed in the Chennai Sub basin in between the Kosasthalaiyar watershed in the north and Adayar watershed in the south. Figure 3.1 Location map of Chennai Coovum watershed. http://iaeme.com/Home/journal/IJCIET 374 [email protected] Statistical Investigation of Ground Water Quality Across Coovum Watershed 4. RESEARCH METHODOLOGY A set of water quality monitoring wells is being maintained by the water resources department and a set of chemical water quality parameters is being observed by the department during every year pre monsoon and post monsoon season. These data is being made available for the analysis by students, research scholars and other departmental staffs. The list of the wells located in the Coovum watershed is shown in the table 4.1 and the corresponding location map of observation wells is shown in the Figure 4.1. Table 4.1 Location of water quality monitoring well across Coovum watershed WELL NUMBER Village WELL NUMBER Village C01 Govindavadi C19 Parthipattu C02 Govinthavadiagaram C20 Ayabakkam C03 Purisai C21 Mugapper West C04 Sriperumbudur C22 Koyambedu C05 Maduramangalam C23 Koyambedu-temple C06 Kumaracheri C24 Saligramam-school C07 Pudupet C25 Saligramam-kovil C08 Kadambathur C26 Arumbakkam C09 Mappedu C27 Arumbakkam-green Tribunal C10 Melnallathur C28 Nugambakkam-park C11 Illuppur C29 Nugambakkam-school C12 Korattur C30 Purasavakkam-school C13 Nemam C31 Perambur-mandapam C14 Thirumazhisai C32 Purasavakkam-mandapam C15 Thandarai C33 Vepery C16 Kannamapalayam C34 Vepery-jain School C17 Avadi C35 Chepauk Hostel C18 Poonamallee C36 Chepauk Figure 4.1 Location map of water quality monitoring well across Coovum watershed The well number is given in sequential order from west to east.