Ganges River water quality was assessed to record the changes due to the nation-wide pandemic lockdown. Satellite-based (Sentinel-2) water quality analysis before and during lockdown was performed for seven selected locations spread across the entire stretch of the Ganges (Rishikesh–Dimond Harbour). Results revealed that due to the lockdown, the water quality of the Ganges improved with reference to specific water quality parameters, but the improvements were region specific. Along the entire stretch of Ganges, only the Haridwar site showed improvement to an extent of being potable as per the threshold set by the Central Pollution Control Board, New Delhi, India. A 55% decline in turbidity at that site during the lockdown was attributed to the abrupt halt in pilgrimage activities. Absorption by chromophoric dissolved organic matter which is an indicator of organic pollution declined all along the Ganges stretch with a maximum decline at the downstream location of Diamond Harbour. Restricted discharge of industrial effluent, urban pollution, sewage from hotels, lodges, and spiritual dwellings along the Ganges are some of the reasons behind such declines. No significant change in the geographic trend of chlorophyll-a was observed. The findings of this study highlight the importance of regular monitoring of the changes in the Ganges water quality using Sentinel-2 data to further isolate the anthropogenic impact, as India continues the phase-wise opening amidst the pandemic.

对恒河水质进行了评估，以记录由于全国大流行封锁而造成的变化。在锁定之前和期间，对恒河（Rishikesh–Dimond Harbour）整个河段中的七个选定位置进行了基于卫星的（Sentinel-2）水质分析。结果表明，由于封锁，恒河的水质相对于特定的水质参数有所改善，但改善是针对特定地区的。在恒河的整个范围内，只有Haridwar站点的改善程度达到了可饮用的程度，达到了印度新德里中央污染控制委员会设定的阈值。锁定期间该地点的浊度下降了55％，这归因于朝圣活动的突然停止。发色溶解的有机物的吸收是恒河沿岸有机污染物下降的一个指标，在钻石港的下游位置下降最大。工业废水的限制排放，城市污染，酒店，旅馆的污水以及恒河沿岸的精神住宅是造成这种下降的部分原因。没有观察到叶绿素-a的地理趋势的显着变化。这项研究的结果凸显了使用Sentinel-2数据定期监测恒河水质变化以进一步隔离人为影响的重要性，因为印度在大流行中继续分阶段开放。工业废水的限制排放，城市污染，酒店，旅馆的污水以及恒河沿岸的精神住宅是造成这种下降的部分原因。没有观察到叶绿素-a的地理趋势的显着变化。这项研究的结果凸显了使用Sentinel-2数据定期监测恒河水质变化以进一步隔离人为影响的重要性，因为印度在大流行中继续分阶段开放。工业废水的限制排放，城市污染，酒店，旅馆的污水以及恒河沿岸的精神住宅是造成这种下降的部分原因。没有观察到叶绿素-a的地理趋势的显着变化。这项研究的结果凸显了使用Sentinel-2数据定期监测恒河水质变化以进一步隔离人为影响的重要性，因为印度在大流行中继续分阶段开放。