Source apportionment for spatial variation of surface water quality using chemometric techniques

In this study, chemometric techniques have been used in source apportionment for spatial variation of surface water quality of seven rivers (Baralia, Puthimari, Pagladia, Beki, Manas, Kolong and Kameng River) of Assam (India). The study was carried out in two phases. The first phase included the survey of the study area and the collection and analysis of water samples. In the second phase, cluster analysis (CA), discriminant analysis (DA) and principal component analysis (PCA) were applied to the observed water quality data-sets. CA grouped all the sampling sites into three clusters based on the similarities of the characteristics they possess. The result from CA was verified using DA, which helped in determining the variables that distinguish the observed groups. DA resulted in eight water quality parameters (DO, total alkalinity, K+, Ca2+, Mg2+, Cl-, SO42- and Mn) affording 100% correct assignations in spatial analysis of rivers. PCA applied to the three separate datasets obtained from CA indicated that soil leaching, organic waste and fertilizer were the major sources of water quality variation. Therefore, the present study illustrates the requisiteness and efficacy of chemometric techniques in source apportionment for variation of water quality and effective management of water resources.