Wednesday, July 22, 2020

Mapping This Year's Cleaner Air

There have been a number of mapped visualizations this year showing how air pollution has decreased in many locations around the world as a result of the lock-downs put in place to try to halt the spread of Covid-19. As a result of the reduction of road traffic and industrial activity many places have witnessed a reduction in NO2 compared to normal levels.

Hiroya Kato has used Japanese NO2 levels downloaded from Google Earth Engine to compare NO2 levels in Japan for this year with the NO2 levels for the same period in 2019. His Covid-19 Impacts map allows you to view 2019 NO2 levels, the 2020 NO2 levels and the difference between the two. This final view shows that this year across nearly the whole of Japan on average NO2 levels have been much lower than in 2019.

If you want to create a similar air pollution comparison map for your own country then Hiroya has written a tutorial on How to Visualize a comparison of NO2 levels using Google Earth Engine data.

Water quality in the Venice Lagoon has improved during the Covid-19 outbreak

The Covid-19 Earth Observing Dashboard uses remote sensing data from ESA, JAXA and NASA to investigate and show how Covid-19 lock-downs have affected Earth’s air, land, and water quality. For example all three space agencies monitor water quality by measuring Chlorophyll-a (Chl) concentrations using satellite optical sensors. These sensors show that in many locations around the world water quality has improved during the Covid-19 outbreak.

The Venice Lagoon in the North Adriatic is usually subject to heavy cruise ship activity. The water quality in the lagoon is also heavily effected by run-off from the Po River, which runs through many different industrialized areas. The decrease in maritime tourism in the lagoon and industrial activity along the Po River during the outbreak has seen unusually low levels of Chl concentration in the Venice Lagoon.

Air quality has improved in many areas of the United States

Air Quality has also improved in many locations around the world. The Covid-19 Earth Observing Dashboard shows that the Northeast United States has seen a 30% drop in NO2 levels compared to the average levels in the previous 5 years. Similar reductions have been seen in Europe, China and India during Covid-19 lock-downs.

You can use the Covid-19 Earth Observing Dashboard to explore the environmental impacts of Covid-19 lock-downs for yourself. The map allows you to search for examples geographically. You can also use the 'indicators' menu to search for examples by environmental, agricultural and economic impacts.

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