Chapter12 - Impact of COVID-19 lockdown on real-time DO–BOD variation of river Ganga

Abstract

A comparative assessment of dissolved oxygen (DO) and biochemical oxygen demand (BOD) of river Ganga during prelockdown and lockdown periods was made through analysis of data generated from real-time water quality motoring systems. The concentration data for DO and BOD are examined for (i) prelockdown period (March 15–21, 2020) and (ii) lockdown period (March 22–April 15, 2020). The analysis results show 3%–20% decrease in DO concentration. The slight decrease in DO observed at all locations during the first week after lockdown which may be due to the increased levels of suspended solids and turbidity in the river water because of heavy rains. DO during fourth week of lockdown has shown a decreased value as compared to the prelockdown period at most of the locations. However, in West Bengal the DO has increased in lockdown. BOD value ranged between 1.13 mg/L and 5.56 mg/L during lockdown period, more or less similar to prelockdown range of 1.37–5.58 mg/L. This chapter further discusses the cause of water quality changes during the period of lockdown as compare to prelockdown period.