Does cloud cover affect EUDR compliance? Summary
- Satellite monitoring supports EUDR compliance using long-term land cover data
- Cloud cover causes temporary gaps but rarely prevents overall compliance assessment
- Very cloudy regions need multi-month mosaics for reliable surface readings
- SAR satellites penetrate clouds providing complementary data mitigating optical limitations
- Combined monitoring approaches reduce non-compliance risks despite persistent cloud challenges
The EUDR has now been delayed twice. The EU’s flagship anti-deforestation regulation has been the subject of intense debate, with its scope and implementation argued and wrangled over in Brussels and beyond.
While politicians disagree over the legal details, companies prepare for regulatory compliance. Traceability is perhaps the single most important aspect of such compliance; in order for an EUDR-relevant commodity to comply with the regulation, it must be traced back to its source.
Tracing commodities all the way back to the plots where they are grown is tricky, as supply chains are almost invariably complex and multi-faceted. Satellites help a lot with this, collecting data would be difficult to find on foot.
What is the EUDR?
The European Union Deforestation Regulation (EUDR) is a piece of legislation that, once implemented, will restrict the entry of deforestation-linked products into the EU. Cocoa, coffee, palm oil, soy, cattle, rubber and wood must not be linked back to land that has had deforestation on it before the cutoff date of 31 December 2020.
Problems with such data collection remain. Cloud cover, for example, can be an impediment to monitoring.
How satellite compliance works
Satellites can aid EUDR compliance through annually updated land cover maps, explains Lucille Denizot, operational marketing at European defence and space manufacturing company Airbus.
These maps leverage long time series of satellite images, building up a complete picture from months of data.
The satellites also monitor the land regularly in order to spot land-cover change.
These satellites visit the same areas frequently, meaning that temporary visibility problems do not pose as much of an issue.
Furthermore, one day missed due to low visibility, suggests Denizot, is not catastrophic for compliance.
“There is no sense of urgency in the EUDR to observe changes on a daily basis, since deforestation and crop cycles are phenomena observable primarily on monthly or yearly scales”.
Is cloud cover a problem?
Because of the long-term nature of the data collected by satellites, explains Denizot, cloud cover is not a major problem.
“Cloud cover may create temporary verification gaps, but deforestation and land-use change are generally analysed over relatively long periods, on a monthly or annual scale, which increases the chances of obtaining cloud-free images in the case of optical imagery.”
Nevertheless, it can be an impediment to monitoring and can reduce the number of usable observations.
This is because it obscures the surface of the land, meaning that it is more difficult for satellites, especially optical satellites, to see what is going on down below.
While cloud cover alone is unlikely to make a product non-compliant, suggests Georgios Raptakis, product manager for TradeAware at software company LiveEO, what it can do is reduce confidence or even delay assessment.
“The key issue is whether cloud and shadow prevent a reliable reading of the land surface across enough observations within the relevant time window. In very cloudy regions, this can require mosaics built over several months rather than relying on a single clear observation.”
Many of the regions for which the EUDR is most relevant – tropical areas in west Africa, southeast Asia and Latin America where its covered commodities are grown – are persistently cloudy. “The problem hits hardest precisely where the EUDR is most focused”, says Marc Loubad, CEO of information services company Veridian Geospatial.
There is, LiveEO’s Raptakis suggests, “still a trade-off between timeliness, cost, and certainty in very cloudy regions”.
Nevertheless, in the view of Airbus’s Denizot, cloud cover only provides “a temporary uncertainty rather than a permanent inability to assess deforestation monitoring”.
‘Seeing’ through the clouds
Satellites do exist that can penetrate cloud cover. For example, the synthetic aperture radar (SAR) satellite sends a pulse of energy to the world below, and uses its interaction with physical structures – forests, mountains, and other features of the landscape – to ascertain what’s there. It can also detect conditions like soil moisture.
Unlike optical satellites, these do not rely on being able to see, meaning that cloud cover and other visual elements are less of an impediment.
“SAR systems emit their own radio waves, allowing them to capture highly detailed images through clouds, smoke and darkness”, says Airbus’s Denizot.
The good news is that access to SAR data is becoming increasingly widespread. The European Space Agency (ESA) offers SAR data collected from its Copernicus Sentinel-1 satellite free of charge.
However, SAR satellites are not perfect. They are highly sensitive, explains Airbus’s Denizot, meaning that numerous false positives have been detected using them.
Therefore, they are rarely used alone but more often in combination with optical satellites.
Furthermore, they are often complex to interpret. “SAR data is not an optical imagery that non expert users can easily interpret”, says Alison Goddard, media relations for UK and Ireland for the European Space Agency.
Overall, while cloud cover can inhibit monitoring and no data gathering method is perfect, the combination of frequent monitoring and the use of SAR can mitigate such problems.
