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EXPLORING HOW COVID-19 IMPACTED THE COUNTRY’S ENVIRONMENT
The unprecedented events of 2020 brought with them an opportunity to study how restrictions on movement and activity affected air quality and urban temperature in the UAE.
If you stood on your balcony in the midst of last year’s lockdown, you may have felt the air was a little bit clearer, the weather a little bit cooler. And it wasn’t your imagination. Research led by United Arab Emirates University (UAEU) faculty has found that pandemic-related restrictions on movement and industrial activity had a direct effect on both air quality and temperature in urban areas.
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Conducted by a team of researchers led by Dr. Abduldaem S. Alqasemi from UAEU, the study came about as a result of the changes to daily life caused by COVID-19. It is the first of its kind, combining analysis of Urban Heat Island (UHI) intensity and air quality in the UAE. UHI refers to an urban area that is significantly warmer than its surroundings. This is caused mainly by the relative lack of vegetation compared to rural/suburban areas, the structures and built-up area, and the activities of its inhabitants – emissions from vehicles, factories, and even air conditioning units.
UHI is considered one of the most noticeable negative consequences of rapid urbanization on the climate and environment. The increased temperature in urban areas often translates to an increased use of energy for cooling, which indirectly contributes to climate change, environmental degradation, air pollution, and poor health outcomes for humans – the severity of coronavirus infection included. A recent study from the Harvard T.H. Chan School of Public Health reported that longterm exposure to polluted air correlated to higher COVID-19 mortality.
Given that the local response to the pandemic has included temporary emiratewide lockdowns, school closures, shifting of office work to work-from-home, and general reduction of movement and industrial activities, Dr. Alqasemi and his collaborators realized there was likely to be an impact on the surface UHI intensity (SUHII) and other environmental metrics. SUHII is defined as a difference in land surface temperature (LST) between urban and rural areas, and therefore requires observations on both.
Recalling the events of last year, Dr. Alqasemi said, “The whole world has been affected by the pandemic. People were forced to change their daily activities, and when there is a large change of this kind, it affects the environment. We had an idea to study how COVID-19-related changes impacted the UAE’s air quality and UHI at the same time that many other researchers were investigating the pandemic’s impact on other places.”
His co-authors on the paper included Dr. Mohamed E. Hereher, Professor of Environmental Earth Science at Damietta University in Egypt; Dr. Gordana Kaplan, Assistant Professor at Institute of Earth and Space Sciences at Eskisehir Technical University in Turkey; Dr. Ayad M. Fadhil Al-Quraishi, Professor of Applied Remote Sensing and GIS at Tishk International University in Iraq; and Dr. Hakim Saibi, Associate Professor of Geology at UAEU.
Left to right: Dr. Hakim Saibi and Dr. Abduldaem S. Alqasemi
- Dr. Abduldaem S. Alqasemi, United Arab Emirates University
The team members focused their observation on Dubai and the Northern Emirates of the UAE, which includes Ras Al Khaimah, Umm Al Quwain, Sharjah, Fujairah, and Ajman. This area was selected as the project’s focus due to the fact that 71% of the country’s population falls within this region, making its study highly relevant to the wider country.
To quantify the impact of reduced transportation and industrial activity on the urban environment in the six targeted emirates, researchers gathered data on nitrogen dioxide, aerosol optical depth (AOD), and temperature from both satellites and on-ground meteorological stations. Nitrogen dioxide is a toxic gas that is produced through vehicle emissions, power plants, and other types of combustion engine-powered machinery.
AOD, meanwhile, is a measure of how particles in the atmosphere block sunlight by scattering it. Data on PM2.5 levels, a measure of fine particulate matter found in the air that is 2.5 micrometers in size, was gathered by researchers in order to assess the AOD. Fine inhalable particles of this sort – be they solid or liquid – are particularly dangerous to humans as they can be absorbed into the lungs and bloodstream.
Data on these three major metrics was gathered for the March-June 2020 period, corresponding to when the UAE imposed a daily curfew from 8pm to 6am in order to reduce the spread of COVID-19. This was compared to data from March-June 2019, when urban activity was normal. The researchers then analyzed the air quality and temperature-related data for the lockdown period and compared it to the previous year. As for what the data revealed? A dramatic drop in SUHII – an average reduction of 19.2% – alongside a 12.2% average reduction in nitrogen levels and 3.7% average drop in AOD. A paper on this research was published in Science of the Total Environment, an international multi-disciplinary journal for publication of novel, hypothesis-driven, high-impact research on the total environment.
A GLOBAL REPORT RELEASED BY SWISS AIR QUALITY TECHNOLOGY COMPANY IQAIR REVEALED THAT ROUGHLY 65% OF CITIES ANALYZED EXPERIENCED BETTER AIR QUALITY IN 2020 COMPARED TO 2019 DUE TO CORONAVIRUS-RELATED RESTRICTIONS ON ACTIVITY
Drilling down by emirate, the SUHII decline was strongest in Fujairah (28.6%) followed by Ras Al Khaimah (23%), Umm Al Quwain (18.8%), Sharjah (17.3%), Dubai (15%), and Ajman (12.3%). Nitrogen dioxide reduction levels by emirate saw the greatest decrease in Ras Al Khaimah (18.6%) followed by Umm Al Quwain (18%), Ajman (13%), Fujairah (11.6%), Dubai (7.6%), and Sharjah (5.4%). The AOD decline was highest in Ajman (5.7%) followed by Umm Al Quwain (5.3%), Sharjah (3.4%), Fujairah (3.1%), Ras Al Khaimah (3.1%), and Dubai (1.7%).
The overall reductions seen in nitrogen dioxide and temperature were attributed to reduced transportation and industrial activity at the onset of the pandemic, including running of heavy machinery, burning of biomass, and emissions from factories. Meanwhile, the relatively smaller reduction in AOD was attributed to the lower levels of precipitation recorded in 2020 compared to 2019, causing more sand and dust to remain in the atmosphere.
The link between COVID-19 shutdowns and improved air quality recorded in Dubai and the Northern Emirates of the UAE is in line with research around the world. A global report released by Swiss air quality technology company IQAir revealed that roughly 65% of cities analyzed experienced better air quality in 2020 compared to 2019 due to coronavirusrelated restrictions on activity.
Another major outcome of the project was the validation of satellite-derived measurements. “The high correlation satellite-derived measurements on pollutants and SUHII to actual measurements on the ground proves that satellites can serve as a significant and reliable resource for researching air quality and SUHII because of the spatial coverage and cost-effectiveness of the data, especially for developing countries like the UAE,” Dr. Alqasemi stated.
The study also contributed to the establishment of a benchmarking paradigm that can assist the UAE government with future and ongoing management of air quality and SUHII.
