Spatio- Temporal Analysis of Turbidity in Ganga River in Patna, Bihar Using Sentinel-2 Satellite Data Linked with Covid-19 Pandemic

Ganga River's water quality has been improved during COVID-19 lockdowns in India (24^th March to 18^th May, 2020) while comparing with the normal days. This study attempted to highlight the variation in river's water quality in terms of spatio temporal turbidity. This study is based on the analysis of remote sensing. Red band known as the most sensitive to estimate turbidity. The temporal variation in turbidity was also investigated through linear regression model using Sentinel-2A, B optical satellite data. It was observed that before lockdown period as on 3^rd March 2020, mean turbidity was estimated as 13.47 FTU (Formazine Turbidity Unit) and during as on 2^nd April 2020, estimated as 11.74 FTU. Further, on 17^th April 2020, it was increased with 0.25 and estimated as 11.99 FTU. Hence, it can be concluded that due to less anthropogenic activity led by the lockdown imposed in the country, water quality of the river is improving continuously. The study also exhibited the relevancy of remote sensing approach to make qualitative estimates on turbidity, when there are no field observations.