A Multivariate Statistical Approach to Pollution Source Identification in Cauvery River, South India

• Published in: Journal of water chemistry and technology Vol. 44; no. 1; pp. 62 - 71
• Main Authors: Mageshkumar, P., Vennila, G., Senthil, K. Angu
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.02.2022; Springer Nature B.V
• Subjects: Ammonia; Anthropogenic factors; Aquatic Pollution; Catchment areas; Cluster analysis; Coliforms; Components; Contamination; Discharge; Dissolved solids; Drinking water; Earth and Environmental Science; Environment; Environmental monitoring; Factor analysis; Faecal coliforms; Fecal coliforms; Governance; Human influences; Impurities; Industrial Chemistry/Chemical Engineering; Industrial pollution; Industrial wastes; Industrial wastewater; Monitoring systems; Multivariate analysis; Natural Waters; Pollutants; Pollution; Pollution sources; River catchments; River water; Rivers; Runoff; Sewage; Spatial variations; Statistical methods; Statistics; Surface water; Total dissolved solids; Turbidity; Urban runoff; Waste Water Technology; Wastewater; Wastewater discharges; Wastewater pollution; Water analysis; Water Industry/Water Technologies; Water Management; Water pollution; Water Pollution Control; Water quality; Water quality standards; Water Quality/Water Pollution; Water sampling; Watersheds; Kaveri River; India; pollution sources; factor analysis; Cauvery River; water quality; cluster analysis
• ISSN: 1063-455X; 1934-936X
• DOI: 10.3103/S1063455X22010052

This paper proposes the multivariate statistical methods, in particular, factor analysis and cluster analysis to assess and interpret the surface water quality of Cauvery River, South India. For this purpose, the surface water samples were obtained from the 50 monitoring stations along the 50 km river stretch during the periods of January 2018 and June 2018. In this approach, 23 parameters were used to measure the quality of collected water samples. The measured levels of turbidity, total dissolved solids, pH, ammonia and fecal coliforms exceed the Bureau of Indian Standards (BIS) for drinking water quality in 58, 35, 12, 11, and 30 samples, respectively. This shows that the surface water of Cauvery River is contaminated by pollutants from catchment area. The factor analysis infers that four principal components represent 71.78% of the total variance in the data set. Nutrient factor, organic factor, chemical factor, and mixed factor were identified as four principal components as per the factored loadings of variables. The agglomerative hierarchical grouping of 50 monitoring stations was carried out by cluster analysis, and these clusters were recognized subject to the spatial variation in surface water quality. Majority of locations (31 sites) fall under low pollution cluster and are influenced by runoff from catchment. The second cluster comprises 14 sampling sites influenced by domestic/urban sewage discharge and comes under moderately polluted category. The high pollution of third cluster is due to the industrial wastewater contamination in 5 monitoring stations. The study indicates that runoff contribution from catchment, urban sewage discharge, industrial wastewater discharge, and natural weathering processes are influencing the quality of Cauvery River water in the selected region. These primary sources are responsible for the abundant ionic concentrations and biological impurities in the Cauvery River. The legitimate treatment of urban and industrial wastewater and governance of anthropogenic activities in the Cauvery River catchment are essential for controlling the potential contamination of surface water.