Indicative Lake Water Quality Assessment Using Remote Sensing Images-Effect of COVID-19 Lockdown

Abstract

The major lockdown due to the COVID-19 pandemic has affected the socio-economic development of the world. On the other hand, there are also reports of reduced pollution levels. In this study, an indicative analysis is adopted to understand the effect of lockdown on the changes in the water quality parameters for Lake Hussain Sagar using two remote sensing techniques: (i) spectral reflectance (SR) and (ii) chromaticity analysis (Forel-Ule color Index (FUI) and Excitation Purity). The empirical relationships from earlier studies imply that (i) increase in SR values (band B2) indicates a reduction in Chlorophyll-a (Chl-a) and Colored Dissolved Organic Matter (CDOM) concentrations, and (ii) increase in FUI indicates an increase in Total Suspended Solids (TSS). The Landsat 8 OLI satellite images are adopted for comparison between (i) January to May of year 2020: the effect of lockdown on water quality, and (ii) March and April for years 2015 to 2020: historical variations in water quality. The results show notable changes in SR values and FUI due to lockdown compared to before lockdown and after unlock suggesting a significant reduction in lake water pollution. In addition, the historical variations within April suggest that the pollution levels are least in the year 2020.

Impacts of COVID-19 on the Aquatic Environment and Implications on Aquatic Food Production

“…Similarly, Pinder et al [37] reported that heavily polluted rivers in India have improved substantially with clean clear waters for the first time in decades. Using remote sending techniques in their study of an Indian lake, Wagh et al [38] noted a significant reduction in chlorophyll a, colored dissolved organic matter, and total suspended solids due low pollution discharges during the COVID-19 lockdown period when anthropogenic activities were restricted, and many large and small scaled industries were closed. In addition, Sun et al [4] also noted that turbidity levels in Wuhan lakes significantly decreased due to the sharp reduction in human activities after the lockdown.…”

The role of remote sensing during a global disaster: COVID-19 pandemic as case study

“…Since the reduction of tourists, water quality along beaches in Acapulco (Mexico), Barcelona (Spain), and Salinas (Ecuador) improved noticeably ( Ormaza-Gonzaìlez et al, 2021 ; Zambrano-Monserrate et al, 2020 ). Wagh found a significant reduction in lake water pollution due to lockdown in Lake Hussain Sagar (India) by using two techniques: spectral reflectance and chromaticity analysis ( Wagh et al, 2021 ). The study also observed that pollution concentration levels in the lake were more uniformly distributed during the lockdown, as compared to before lockdown, after the lockdown was lifted (2020) or previous years (2015–2019).…”

“…The study also observed that pollution concentration levels in the lake were more uniformly distributed during the lockdown, as compared to before lockdown, after the lockdown was lifted (2020) or previous years (2015–2019). This suggests that the lake pollutant concentration was uniformly distributed on the lake surface due to low effluent influx during the lockdown ( Wagh et al, 2021 ).…”

Gis And Remote Sensing: A Review Of Applications To The Study Of The Covid-19 Pandemic

“…After the SARS-CoV-2 virus quickly spread across the globe, this problem has received much attention from several authors in the worst-affected countries such as India, Spain, and Italy. To understand the effects of COVID-19 lockdown, Wagh et al (2021) assessed the indicative lake water quality for the Lake Hussain Sagar (India) using Landsat-8 sensor Operational Land Imager (OLI). This study results have shown that there were a reduction in Chlorophyll-a (Chl-a) and Colored Dissolved Organic Matter (CDOM) concentrations and a significant reduction in lake water pollution (Wagh et al 2021).…”

“…To understand the effects of COVID-19 lockdown, Wagh et al (2021) assessed the indicative lake water quality for the Lake Hussain Sagar (India) using Landsat-8 sensor Operational Land Imager (OLI). This study results have shown that there were a reduction in Chlorophyll-a (Chl-a) and Colored Dissolved Organic Matter (CDOM) concentrations and a significant reduction in lake water pollution (Wagh et al 2021). From the above discussion, it can be concluded that there has been an improvement in the water quality during the COVID-19 lockdown.…”