180
A. Chauhan
water quality [76]. Patel, Mondal and Ghosh (2020) stated that despite of various
plans for restoration, the River Yamuna in Delhi as one of the dirtiest rivers in India
due to unabated rise in pollution. Lockdown imposed due to COVID-19 pandemic
nationally provided a ray of hope. The impact on water quality of Yamuna was
analysed using a satellite images and combination of measurable parameters. There
was an improvement of 37% during the lockdown in Class C Water Quality Index
estimates of nine stations. Similarly Chemical Oxygen Demand and BOD values
were reduced by 39.25 and 42.83% and Faecal coliform decreased by over 40%
in comparison to the pre-lockdown phase. Further 20 major drains were analysed
and depicted reduced contaminant and effluent loads. Thus, if polluting actions and
contaminants that are deleterious are regulated appropriately it is possible that our
rivers can recover with better water quality [52]. Garg et al. (2020) affirmed that
the quality of water in Ganga has improved during vide country-wide lockdown
and this change was studied through Sentinel-2 multispectral remote sensing data in
terms of turbidity at Varanasi, Haridwar, Prayagraj and Kanpur and observed that at
each stretch of the river the turbidity in the river has reduced drastically [24]. Dhar
et al. (2020) in their analysis on dissolved oxygen (DO) along the stretch of River
Ganga in 6 sites during 2nd, 9th, 16th and 23rd April 2020 (COVID-19 lockdown
period) in comparison to the data of 2015–2019 saw a decrease in dissolved oxygen
(DO) providing congenial environment for flourishing of aquatic biodiversity and
improving the water quality during lockdown [16]. Dutta et al. (2020) stated that due
to the eight week nationwide lockdown in India rejuvenation of Ganga River has
taken place due to negligible discharge of industrial waste and agricultural runoff.
Further 60% excess rainfall than the normal was observed in the Ganga basin diluting
the pollutants with 82.83% more than the average water storage in past ten years,
reduction in Total coliform and nitrate (NO 3 –) concentration, Faecal coliform and
biological oxygen demand (BOD) and an increase in dissolved oxygen (DO) [17].
Selvam et al. (2020) conducted the study on 22 groundwater samples from the coastal
industrial city of Tuticorin in Southern India to describe the biological and chemical
changes of water by taking samples before 10 and 11 February 2020 and during
the lockdown (19 and 20th April 2020) and found significant reductions in metals
due to decrease in wastewater discharge from thermal power plants, metal-based
industries and seafood-based industries and also reduction in faecal coliforms, total
coliform and NO 3 due to decrease in organic sewage from the fishing industries and
conclude that by seizing of anthropogenic activities groundwater can quickly revive
[59]. Chakraborty et al. (2020) in their study on three station of lower Gangetic delta
region found that there was a significant increase in the dissolved oxygen (DO) during
COVID-19 lockdown in comparison to the level of dissolved oxygen of the last thirty
years (1984–2019) [8]. Arif, Kumar and Parveen (2020) confirmed a highly positive
change in nature’s behaviour during lockdown period due to Corona pandemic giving
an opportunity for earth’s hydrosphere, atmosphere and biosphere to rejuvenate and
studied the water quality of Yamuna River in Delhi one of the most polluted river of
India and found a very impressive recovery in lockdown [2].
A. Chauhan
water quality [76]. Patel, Mondal and Ghosh (2020) stated that despite of various
plans for restoration, the River Yamuna in Delhi as one of the dirtiest rivers in India
due to unabated rise in pollution. Lockdown imposed due to COVID-19 pandemic
nationally provided a ray of hope. The impact on water quality of Yamuna was
analysed using a satellite images and combination of measurable parameters. There
was an improvement of 37% during the lockdown in Class C Water Quality Index
estimates of nine stations. Similarly Chemical Oxygen Demand and BOD values
were reduced by 39.25 and 42.83% and Faecal coliform decreased by over 40%
in comparison to the pre-lockdown phase. Further 20 major drains were analysed
and depicted reduced contaminant and effluent loads. Thus, if polluting actions and
contaminants that are deleterious are regulated appropriately it is possible that our
rivers can recover with better water quality [52]. Garg et al. (2020) affirmed that
the quality of water in Ganga has improved during vide country-wide lockdown
and this change was studied through Sentinel-2 multispectral remote sensing data in
terms of turbidity at Varanasi, Haridwar, Prayagraj and Kanpur and observed that at
each stretch of the river the turbidity in the river has reduced drastically [24]. Dhar
et al. (2020) in their analysis on dissolved oxygen (DO) along the stretch of River
Ganga in 6 sites during 2nd, 9th, 16th and 23rd April 2020 (COVID-19 lockdown
period) in comparison to the data of 2015–2019 saw a decrease in dissolved oxygen
(DO) providing congenial environment for flourishing of aquatic biodiversity and
improving the water quality during lockdown [16]. Dutta et al. (2020) stated that due
to the eight week nationwide lockdown in India rejuvenation of Ganga River has
taken place due to negligible discharge of industrial waste and agricultural runoff.
Further 60% excess rainfall than the normal was observed in the Ganga basin diluting
the pollutants with 82.83% more than the average water storage in past ten years,
reduction in Total coliform and nitrate (NO 3 –) concentration, Faecal coliform and
biological oxygen demand (BOD) and an increase in dissolved oxygen (DO) [17].
Selvam et al. (2020) conducted the study on 22 groundwater samples from the coastal
industrial city of Tuticorin in Southern India to describe the biological and chemical
changes of water by taking samples before 10 and 11 February 2020 and during
the lockdown (19 and 20th April 2020) and found significant reductions in metals
due to decrease in wastewater discharge from thermal power plants, metal-based
industries and seafood-based industries and also reduction in faecal coliforms, total
coliform and NO 3 due to decrease in organic sewage from the fishing industries and
conclude that by seizing of anthropogenic activities groundwater can quickly revive
[59]. Chakraborty et al. (2020) in their study on three station of lower Gangetic delta
region found that there was a significant increase in the dissolved oxygen (DO) during
COVID-19 lockdown in comparison to the level of dissolved oxygen of the last thirty
years (1984–2019) [8]. Arif, Kumar and Parveen (2020) confirmed a highly positive
change in nature’s behaviour during lockdown period due to Corona pandemic giving
an opportunity for earth’s hydrosphere, atmosphere and biosphere to rejuvenate and
studied the water quality of Yamuna River in Delhi one of the most polluted river of
India and found a very impressive recovery in lockdown [2].