Comprehensive Spatio-temporal Benchmarking of Surface Water Quality of Hindon River, India– a Tributary of River Yamuna, India

Abstract The quality of Hindon River, western Uttar Pradesh, India was benchmarked with 19 sampling sites by analysing seventeen water quality parameters and eight heavy metals for pre and post-monsoon seasons to assess the existing quality of water which is a milestone for preparing roadmap for its betterment. Indices associated with water quality and heavy metals were computed to scale the accurate state of risk associated to its use for drinking and irrigation. During the pre and post-monsoon seasons, only four and five sites were found having safe water quality index (WQI) values respectively. The average WQI (2015–2019) for pre and post-monsoon seasons ranged between 8.69–706.47 and 7.20–341.56 respectively. During pre-monsoon and post-monsoon seasons w.r.t. drinking purpose, heavy metal pollution index ranged between 0.76–4470.78 and 0–1425.31 respectively; heavy metal evaluation index ranged between 0.21–163.11 and 0.00–57.70 respectively; contamination evaluation index ranged between -7.79–155.11 and –8.00 to 49.70 respectively. During pre-monsoon and post-monsoon seasons w.r.t. irrigation purpose, heavy metal pollution index ranged between 0.82–1492.71and 0.00–300.06 respectively; heavy metal evaluation index ranged between 0.10–20.44and 0.00–5.66 respectively; contamination evaluation index ranged between -15.97–10.03and –17.00 to –6.08 respectively. The heavy metals were positively correlated where highest value observed between Cu and Mn (correlation coefficient value 0.95). For physico-chemical parameters, observed adj-R2 value ranged from 0.50 for pH to 0.98 for total hardness and calcium. PCA analysis achieves three principle components (PCs) for physico-chemical and three PCs for heavy metals that explained 88.67% and 89.68% variability of the original data set, respectively.