What’s the connection between white asparagus, soft fruit, plastic tarps, and trucks? Each had a role in recent satellite image analysis that shows a major indirect impact of COVID-19. Research by the geomatics team of Pierre Defourny, a specialist in Earth observation by satellite, demonstrates the fragility of our agricultural sectors.
In the struggle against the COVID-19 crisis, as microbiologists subject the coronavirus to microscopes, Earth observation specialists subject the planet to satellites. What’s the connection? COVID-19’s indirect impact on agriculture. Satellite images reveal many of the economic, social and environmental consequences of the global health crisis. Thus the European Commission and the European Space Agency launched their Rapid Action on Coronavirus and Earth Observation (RACE) dashboard, to which the team of Prof. Pierre Defourny (ELI/AGRO) contributes. Indeed, through its Copernicus programme, Europe has become the world leader in Earth observation. It was obvious to both bodies that quantifying COVID-19’s impact in real time was urgently required.
The goals of the RACE dashboard are clear: to provide information on the state of Europe’s societies and economies, while focusing on air and water quality, economic indicators (industry, trade, construction, maritime and road traffic), and agriculture. It’s for the last sector that Prof. Defourny’s team was solicited. Given its expertise in Earth observation by satellite and the development of open source tools to help the agricultural sector (BELCAM, Sen4CAP and Sen2Agri), the team didn’t hesitate to take up the challenge. ‘Half of our laboratory became involved in this project because researchers wanted to mobilise their skills in the face of the COVID-19 crisis,’ Prof. Defourny explained. ‘So we’ve been able to develop solutions which make it possible to continuously supply indicators derived from data collected by satellites and to see the impact of confinement.’
An example: white asparagus in Germany
So-called ‘white gold’, white asparagus is widely consumed in Germany in the spring, especially during traditional Easter meals. ‘To meet this demand and ensure the harvest,’ Prof. Defourny says, ‘between March and June farmers need the help of 80,000 seasonal workers from Bulgaria and Romania – workers who couldn’t travel to Germany because of confinement. Using the frequent passage of Sentinel satellites, we’ve monitored the production of white asparagus, while continuously comparing it to the situation in 2019 to identify unharvested areas. The fields are covered with black or white plastic tarps. In satellite images, changes in colour indicate the tarps have been changed in order to regulate temperature, and are thus proof of activity. Hence we had a production area indicator and an activity indicator.’ The scientists have thus been able to demonstrate a reduction in productivity of 22 to 30% for white asparagus in the state of Brandenburg.
Soft fruit and trucks
For strawberries, raspberries and other soft fruit from Spain’s Huelva Province, the team proceeded differently: they analysed satellite images for truck activity between greenhouses where soft fruit grows. Beginning in March, the team observed a 26.5% drop in harvest-related truck activity compared to 2019.
Huelva Province produces 97.5% of Spain’s soft fruit and leads the world in strawberry exports. It suffered horribly from a shortage of 25,000 seasonal workers, who usually come mainly from Morocco, and a steep drop (40 to 60%) in demand for these perishable products during the confinement period.
‘In addition to the fall in production,’ Prof. Defourny explains, ‘it’s important to highlight our agricultural sectors that are largely dependent on these “invisible” workers, seasonal migrants not recognised by our society but who are in fact key players in the quality of our food. It’s a way of showing how fragile our food system will be if producers aren’t really recognised and respected.’
Praised approach and results
In addition to these two somewhat atypical studies, the team also launched a data analysis concerning Spain’s cereal harvest. ‘The official statistics generally take six to eight months to come out,’ Prof. Defourny says, ‘which is very late to react when the figures are bad. The tool developed here allows us to monitor harvests continuously and calculate the harvested areas as we go along.’
The team’s initiatives and results were presented and highly praised at the European Commission’s 5 June RACE press conference, as well as at the 16 June virtual world congress of the Group on Earth Observations, a worldwide organisation that promotes geospatial data.
‘As specialists in Earth observation by satellite, we of course don’t pretend to conduct complex analyses of the COVID-19 virus itself. We rather aim to react to a crisis by weekly updating indicators that we’ve designed to document an unprecedented situation and highlight the essential role of “invisible” workers.’ Their reaction enables the scientific community to meet the demand for information that can be used by policymakers, thus ensuring satellite data help make transparent how we are really living.
Audrey Binet
View the European Commission’s 5 June RACE press conference: