Clean river water is an essential and life-sustaining asset for all living organisms. The upper Ganga and Yamuna river system has shown signs of rejuvenation and tremendous improvement in the water quality following the nationwide lockdown due to the coronavirus pandemic. All the industrial and commercial activity was shut down, and there was negligible wastewater discharge from the industries. This article addresses the water quality assessment from the study area, which is based on the original data of physical parameters, major and trace elements, and stable isotopes (hydrogen and oxygen) systematics during the nationwide lockdown. The impact of the lockdown could be seen in terms of an increase in dissolved oxygen (DO). Water samples were collected from the Upper Ganga and Yamuna river basins (Alaknanda, Bhagirathi, and Tons rivers) during an eight-week lockdown in Uttarakhand, India. We discussed the signs of rejuvenation of riverine based on physical parameters, major ions, trace elements, isotopic ratios, and water pollution index (WPI). Results reveal that the water quality of the entire upper basins of the Ganga has significantly improved by 93%, reflecting the signs of self-rejuvenation of the rivers. Multivariate analysis suggests a negative factor loading for an anthropogenic element ( $${NO}_{3}^{-}$$ ), implying that they contribute little to the river water during the lockdown. Further, bicarbonate ( $${HCO}_{3}^{-}$$ ) is a dominant element in both river basins. The geochemical facies are mainly characterized by the ( $${{Ca}^{2+} :{Mg}^{2+} : HCO}_{3}^{-}$$ ) type of water, suggesting that silicate rock weathering dominates with little influence from carbonate weathering in the area. The positive factor loadings of some cations, like $${HCO}_{3}^{-}$$ , $${Ca}^{2+}$$ , and $${Mg}^{2+}$$ reflect their strong association with the source of origin in the lockdown phases. Stable isotopic reveals that the glaciated region contributed the most to the river basin, as evidenced by the low d-excess in riverine water compared to anthropogenic contributions. Rivers can self-rejuvenate if issues of human influence and anthropogenic activities are adequately resolved and underline our responsibility for purifying the ecosystem. We observed that this improvement in the river water quality will take a shorter time, and quality will deteriorate again when commercial and industrial activity resumes.

中文翻译：

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COVID-19 大流行引发的封锁期间恒河上游和亚穆纳河系统的水质评估：河流复兴的印记


清洁的河水是所有生物体维持生命的重要资产。在因新冠病毒大流行而实施全国封锁后，恒加河和亚穆纳河上游水系已显示出恢复活力和水质大幅改善的迹象。所有工业和商业活动都被关闭，工业废水排放量微乎其微。本文介绍了研究区的水质评估，该评估基于全国封锁期间的物理参数、主量元素和微量元素以及稳定同位素（氢和氧）系统的原始数据。封锁的影响可以通过溶解氧（DO）的增加来体现。在印度北阿坎德邦为期八周的封锁期间，从恒河上游和亚穆纳河流域（Alaknanda、Bhagirathi 和 Tons 河）采集了水样。我们根据物理参数、主要离子、微量元素、同位素比和水污染指数（WPI）讨论了河流复兴的迹象。结果显示，恒河上游整个流域的水质明显改善了93%，体现了河流自我复兴的迹象。多变量分析表明人为因素（ $${NO}_{3}^{-}$$ ）存在负因子负载，这意味着在封锁期间它们对河水的贡献很小。此外，碳酸氢盐 ( $${HCO}_{3}^{-}$$ ) 是这两个流域的主要元素。地球化学相主要以($${{Ca}^{2+} :{Mg}^{2+} : HCO}_{3}^{-}$$ )类型水为特征，表明硅酸盐该地区以岩石风化为主，碳酸盐风化影响较小。 某些阳离子的正因子载荷，例如 $${HCO}_{3}^{-}$$ 、 $${Ca}^{2+}$$ 和 $${Mg}^{2+}$ $ 反映了它们与封锁阶段的来源地的紧密联系。稳定同位素表明，冰川区域对流域的贡献最大，与人为贡献相比，河水中的 D 过量较低就证明了这一点。如果人类影响和人类活动的问题得到充分解决，河流就可以自我复兴，并强调我们净化生态系统的责任。我们观察到，河流水质的改善需要的时间较短，当商业和工业活动恢复时，水质会再次恶化。