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


 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.


35
Water being an essential commodity for human life, its availability in superior quality w.r.t. 36 its use in drinking, irrigation, cultural has become one of the greatest challenges of the 37 present world. The concern for sustainable water availability in terms of quality and quantity  Smith et al. 1992). Furthermore, long stretch exposure of heavy metals even at low 76 concentrations can be a persuasive health hazard (Jiang et al. 2008). 77 The evaluation of surface water quality of some past studies was mainly focussed on distribution pattern of water quality variables and heavy metals for characterizing the 85 potential ecological risk in surface water has always been a very important concern for 86 policymakers and scientific community globally. 87 In order to sustain the water in terms of its quality, it is utmost imperative to 88 benchmark current status of surface quality and rank them accordingly. Keeping this in view, 89 the present study was conducted to determine the impact of various anthropogenic actions on 90 riverine system water quality and establish the link between different exhaustive water 91 quality parameters including toxic heavy metals in Hindon River, western U. P., India. The 92 results of this study will be definitely helpful for the stakeholder agency, policy makers to 93 devise instantaneous measures to mitigate the surface water pollution and restoring the 94 natural water bodies. Further, our study would contribute in achieving goals 3, 6, 12, 14, 15 95 and 17 of United Nations' sustainable development goals (SDGs) and contribute to prepare a 96 roadmap for inclusive appraisal of water contamination in surface waters globally.  Heavy metal pollution index (HPI) 176 The HPI represents the superiority and suitability of water for drinking purpose pertaining to

197
The HEI method gives the overall quality of the water with respect to heavy metals during pre and post-monsoon (Fig. 2K).

334
Chlorides (Cl -) are a naturally occurring element and also a contaminant. A major 335 anthropogenic source of Clis water softeners utilized for industrial/commercial purposes.

336
Chloride is not toxic to humans but increased concentration makes water unpotable due to the

371
To recapitulate the differences in different variables of water quality for Hindon 372 River, statistical difference were evaluated at 95% confidence level.

373
Comparing the concentration pattern of ions as a whole followed the order of HCO3 ->Cl -

638
DO and Turbidity whereas PC3 included EC only (Fig. 9a-c).  (Table 7). In addition, the heavy metals were patriated in 645 three component models using factor map. In the factor map, PC1 included Cr, Pb, Zn, Mn, 646 and Cu, while Fe was constituted by PC2, whereas Cd was included by PC3 (Fig. 10a-c).    Ethics approval and consent to participate Not applicable.

872
Consent for publication Not applicable.

Conflict of interest
The authors declare no competing interests.