Innovative New Data Detects Disturbances in Near-Real-Time for All the World's Vegetated Land
By Sarah Carter and Fred Stolle and Amy Pickens (University of Maryland)
Apart from forests, many of the world’s vital ecosystems remain largely unmonitored, such as the savannas of Africa and the northern steppe, yet they are threatened by human activities and impacted by climate change. To solve this challenge, Land & Carbon Lab is embarking on an ambitious journey to redefine the frontiers of ecosystem monitoring.
In a major step toward comprehensive ecosystem monitoring, our partners at the University of Maryland (UMD) have worked with NASA’s OPERA project to produce a groundbreaking new land surface disturbance monitoring system known as OPERA Land Surface Disturbance Alert, or OPERA DIST-ALERT. This first-of-its-kind monitoring product detects disturbances to any kind of vegetation cover, including forests, grasses, shrubs and even crops, occurring anywhere on Earth in near real-time.
Land & Carbon Lab will continue to work with UMD to turn this data into targeted near real-time alert products to create impact on the ground. These could be used for many possible applications, such as tracking agricultural expansion into natural lands, detecting degradation dynamics like logging, and monitoring generally short-lived vegetation changes like drought and fire.
This product will enhance Global Forest Watch’s existing alerts for tropical forests by expanding alerts to forests globally, allowing anyone, anywhere to monitor all forests in near real-time.
DIST-ALERT Showing Vegetation Loss Related to Soy Expansion in the Brazilian Cerrado
How does the new disturbance monitoring product work?
OPERA’s DIST-ALERT product is derived through a time-series analysis of harmonized data from the NASA/USGS Landsat and ESA Sentinel-2 satellites (known as the HLS data set), and identifies and continuously monitors vegetation in 30-m pixels across the globe.
Since January 2023, the data has tracked vegetation cover and disturbance based on new satellite information acquired every 2-4 days. The product detects notable reductions in vegetation cover (measured as “vegetation fraction” or the percent of the ground that is covered by vegetation) for every pixel every time the new satellite data is acquired and the ground is not obscured by clouds or snow.
The new vegetation fraction estimate is compared to the minimum fraction for the same time period (within 15 days before or after) in the previous 3 years, and if there is a reduction of at least 10% cover, then the system identifies an alert in that pixel. Because the product compares each pixel to the minimum for the same time period in previous years, it takes into account regular seasonal variation in vegetation cover.
What does the data show us?
This new data can capture many different types of changes to the Earth’s vegetation and shows the location and date of important dynamics as they are happening.
The data shows seasonal anomalies within both natural and human-managed vegetation cover, which includes forests as well as grasslands, shrublands and crops. These anomalies may be long-lasting changes driven by human activities (like agricultural expansion) or natural causes (like landslides), or may be temporary events (like shifts in planting or drought damage in crops).
While OPERA DIST-ALERT provides disturbance alerts, it does not provide information about what is causing the disturbances. To make this data more actionable for users, we will combine it with other land cover and land use maps to identify notable types of change and an indication of what is causing them.
How could the data be used to better monitor changes in land and forests?
Land & Carbon Lab is working with UMD to create new open and transparent products by integrating the data with other information in order to serve a wide range of users, from researchers to land managers and journalists. These new data products can be integrated into platforms such as Global Forest Watch (GFW).
Although the data is new and more research is needed to fully understand all the possibilities for its use, Land & Carbon Lab and UMD have identified three priorities:
1. Providing near-real-time forest change information outside of the tropics
Currently, GFW provides forest disturbance alerts indicating possible deforestation in dense tropical forests. The new global data will provide alerts outside the humid tropics that are not covered by current GFW alerts, such as the expansive forests in Europe and North America and dry forests in East Africa. Additionally, both natural and commercial forests will be monitored.
DIST-ALERT could potentially be added to GFW’s integrated deforestation alerts layer, which provides quicker and more accurate information than one alert system alone. It also means that users do not have to make decisions about which alert system to use when more than one is available in their area of interest.
Greater coverage means more information available to users for early action on potential illegal deforestation. It can also directly support those monitoring compliance with regulations such as the EU Deforestation Regulation (EUDR), a new law that prohibits products linked to deforestation and forest degradation from being sold in the EU. Information on disturbances to vegetation enables continuous monitoring and early notifications on possible deforestation, which is important for enforcing the regulation.
2. Providing information on conversion of non-forested vegetated land to agriculture
Many commodity suppliers are looking to ensure and demonstrate sustainability in their supply chains, which means no deforestation and no conversion of non-forested natural lands, such as grasslands, to agriculture. The new OPERA DIST-ALERT data will make it possible to identify alerts that are likely due to conversion of non-forested natural vegetation to commodity production. We can identify these likely commodity production areas by overlaying data sets such as current crop extents, slope and climatic parameters.
This will provide the possibility for interested stakeholders to monitor the impact of their agricultural supply chains in areas outside of forests. For example, in November 2023, Cargill committed to eliminate conversion in addition to deforestation from its direct and indirect supply chain for key row crops in Brazil, Argentina and Uruguay by 2025. Alerts can contribute to monitoring compliance in these mainly non-forested systems and can support quick action where conversion may be taking place. Alerts in non-forested areas could also be relevant to the EUDR, which although is currently limited to conversion in forests, could potentially expand to “Other Wooded Land” (non-agricultural land with few trees that can include shrubs and bushes) and require identifying conversion of this land cover to crop land, which this new data could support.
3. Providing better insights on vegetation health for land managers in a changing world
Moving beyond human disturbances, this new data can potentially provide early information about other worrying trends in the world’s natural ecosystems such as the impacts of droughts and climate change.
By tracking alerts within valuable lands such as protected areas, biodiversity hotspots and Indigenous lands, and crosschecking with other information such as weather anomalies or fires, land managers could better tell what’s going on in these areas to identify threats and support their decision making.
The UN Convention on Biological Diversity’s global biodiversity framework includes the ambitious “30x30 initiative,” which aims to protect 30% of the planet's land and water by 2030. Alerts within these protected areas could give an early warning of threats to their long-term conservation and represent locations where swift action should be considered.
What’s next for vegetation disturbance monitoring from Land & Carbon Lab and UMD?
OPERA DIST-ALERT requires additional context or expertise to be able to identify the type of change, and therefore to make it application ready. Land & Carbon Lab and UMD are currently exploring how the product performs in specific geographies and vegetation types, using various existing data sets to filter the data to identify particular types of change. We are also working on providing information about the disturbances, such as distinguishing temporary changes like droughts and natural flooding from human activities like deforestation in tropical primary forests and conversion of natural grasslands to croplands. This work has already begun for the forest alerts, where new research by our partners has identified drivers of deforestation alerts in the Congo basin. Efforts to expand this to other regions and make it available on GFW are underway.
GFW currently filters our integrated alerts to identify the most concerning areas, or “Places to Watch,” of deforestation, including those driven by expansion of the major commodities palm oil and soy. Applying these filters to OPERA’s DIST-ALERT will highlight where large areas of vegetation disturbance is taking place. An expansion of this approach to other regions, vegetation types and commodity types will provide valuable information on the sustainability of supply chains.
Land & Carbon Lab and UMD are continuing to build on this data and evaluate potential tools and platforms to make it easier to access actionable information on land and forests. Throughout this process, Land & Carbon Lab will offer webinars, materials and training events to enable all stakeholders to use this valuable resource.
Land & Carbon Lab is also developing many other data products in collaboration with leading experts in land monitoring that we will be rolling out throughout 2024 — stay tuned to hear about the latest in innovations in monitoring for people, nature and climate.
Watch a recording of our webinar to learn more about how groundbreaking advancements in conversion monitoring are making it possible to protect all natural ecosystems.
The OPERA project is funded by NASA to address remote sensing needs identified by the Satellite Needs Working Group. Managed by NASA’s Jet Propulsion Laboratory, OPERA funds and manages UMD’s DIST-ALERT product development. All OPERA products are free and openly available through the NASA public data archives. Learn more here.
Land & Carbon Lab is proud to fund our partners at the University of Maryland Global Land Analysis and Discovery Lab research into land cover, land use and land cover change mapping and monitoring. This includes turning OPERA DIST-ALERT into targeted near real-time alert products. Learn more here.