Does Social Distancing Have an Effect on Water Quality? : An Evidence from Chlorophyll-a Level in the Water of Populated Southeast Asian Coasts

Abstract

The COVID 19 related social distancing is hypothesized can affect the environmental quality including the air and water quality. Correspondingly, this study aims to study how the reduction of activities of people living near the rivers and the coastal areas due to social distancing may decrease the discharges of materials and nutrients to the water body. The chlorophyll-a was used as bio indicators of nutrient contents related to the anthropogenic activities in the coast. The study was conducted in the Jakarta coast considering that this coast was surrounded by populated cities with total population equal to 16 million people. The chlorophyll-a was measured in mg/m3 and monitored using remote sensing data from January to April 2020 representing the period before and after the implementation of social distancing. The determinant environmental factor measured was sea surface temperature (0C). The study considered that there were reductions of levels and areas of chlorophyll-a in the coast. The chlorophyll-a levels were reduced from January to April (p<0.05). The chlorophyll-a levels for January, February, March, and April were 7.36 mg/m3 (95%CI: 6.34-8.37), 7.90 mg/m3 (95%CI: 7.32-8.47), 6.52 mg/m3 (95%CI: 5.37-7.66), and 4.21 mg/m3 (95%CI: 3.34-5.07) respectively. However, the differences of chlorophyll-a were not influenced by the sea surface temperature factor (p>0.05). Based on remote sensing data in January and February, the sizes of coastal areas with chlorophyll-a levels >7.00 mg/m3 were larger than areas observed in March and April. Contrarily, the coastal area sizes with low chlorophyll-a levels <5.00 mg/m3 were increasing in April. To conclude the dynamic of anthropogenic activities in coastal setting is responsible and associated with the water quality and nutrient contents as indicated by chlorophyll-a levels.

Impact Assessment of PSBB on Variations of NO2, CO, and Chlorophyll-a Concentration in Java Island during the COVID-19 Pandemic based on Multi-satellite Imagery Data

“…However, the reduction of chlorophyll-a concentration was distinguishable when the concentration was observed in the pandemic compared to the previous year (Figure 8). This result is in line with chlorophyll-a study in Jakarta by Adwibowo (2020). They concluded that the dynamic of anthropogenic activities was responsible and associated with the water quality and nutrient as indicated by chlorophyll-a in the coastal.…”

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

“…These findings were consistent with those reported by many studies (Arif et al 2020;Najah et al 2021;Yunus et al 2020). In this study, Adwibowo (2020) investigated the effects of social distancing on water quality in the Jakarta coast based on remote sensing data captured by Copernicus Sentinel-3B Ocean and Land Color Instrument in January and February of 2020, Adwibowo (2020) figured out that there were reductions of levels and areas of chlorophyll-a in the coast as a function of social distancing and activity restrictions. Weeks later, with the help of Sentinel-2A images and the ArcGIS software, Parra Boronat (2020) 2020) have shown that a remarkable reduction of the turbidity during the lockdown, due to the COVID-19 pandemic and capture the high values of total suspended matter (TSM) during the flood condition.…”

A satellite-based investigation into the algae bloom variability in large water supply urban reservoirs during COVID-19 lockdown

“…Similar approach was carried out for coastal areas in Indonesia (Adwibowo 2020), but further study of the impact of COVID-19 on freshwater quality has never been conducted. The Chl-a concentration is considered a general indicator for plankton biomass and the PC is characteristic of the presence of cyanobacteria (Simis et al 2005).…”