Assessment of heavy metal contamination in water of Kali River using principle component and cluster analysis, India

The Kali River is an intermittent river in western Uttar Pradesh (U.P), which receives a huge amount of untreated wastewater containing toxic heavy metals from industrial and urban discharge. The present study aims to assess the heavy metals (Fe, Cd, Zn, Cr, and Pb) contamination in Kali River using heavy metal pollution index (HPI) during pre- and post-monsoon periods in year 2014. The assessment also involves hierarchical cluster analysis (HCA) and principal component analysis (PCA) for identification of clusters of sampling locations of similar pollution characteristics, determination of regional water quality variables and their input sources. The result indicates that the overall water quality in Kali River is severely contaminated (i.e., mean HPI >1) with respect to heavy metals concentration and could pose a likely threat to flora and fauna. The outcome of HCA classified similar water quality stations into two clusters and PCA demonstrating up to 97 and 94% of both temporal and spatial changes during pre- and post-monsoon periods, respectively.