Assessment of Seasonal Variations in Surface Water Quality of Cooum River in Chennai, India – A Statistical Approach

Rapid development in industrial sectors and population expansion has adverse impact on the Cooum river basin, especially Chennai region. The present study focuses on the assessment of seasonal variation in surface water quality of Cooum river basin. The samples were collected seasonally and are categorized as pre-monsoon, monsoon and post-monsoon during March 2013 to March 2014. Eighteen physicochemical parameters were assessed for eleven different samples collected along the channel of Cooum river basin. Statistical tools such as correlation analysis scatter plots, box plot and multivariate tools such as cluster analysis and principal component analysis were applied to categorize the Cooum river water quality. From the data sets, the ionic concentration, organic loads exhibits positive correlation (R²>0.7) for all three seasons. Also, box plot and scatter plot results revealed that during post-monsoon season the ionic concentration along with organic and inorganic levels were slightly higher than monsoon and pre-monsoon. Similarly, multivariate statistical tools such as principle component analysis (PCA) indicate that the ionic concentrations and organic load contributed more than 50% of variance while cluster analysis (CA) reveals that nature of pollutant load among the sites.