Service overview

EU Grassland Watch uses optical images from both the Copernicus Sentinel-2 and the US Landsat systems to create a rich time series of data and allow for the filling of gaps caused by clouds, cloud shadow, and snow. The use of Landsat data also allows the extension of the time series of grassland information back beyond the Sentinel era to 1994.

Optical data is more familiar to users of aerial photographs as it is similar to the human eye.

EU Grassland Watch also uses synthetic aperture radar (SAR) images from the Copernicus Sentinel-1 satellite constellation to support the monitoring process from 2014 onwards. SAR is an active system which acquires images day and night in all weather, so cloud cover does not create gaps in SAR imagery that need to be filled.

Due to the wavelengths used by SAR, the data reflect the macro-scale structure of the surface, which we perceive as roughness.

EU Grassland Watch used several reference datasets to guide the processing of Earth Observation (EO) data and support the analysis.

EU Grassland Watch integrates existing products from the Copernicus Land Monitoring Service (CLMS) more closely into its production process to reduce duplication across applications. For example, the project used the High Resolution Vegetation Phenology and Productivity (HR-VPP) dataset. The earlier COP4N2K project had calculated its own phenology and productivity variables.

One of the key requirements for EU Grassland Watch was to optimise how it processes and stores Earth Observation (EO) imagery. With traditional EO infrastructure, this work requires substantial computing resources and depends heavily on local processing and storage capacity, which makes it difficult to scale up.

openEO simplifies this workflow through an open API which gives EO data users access to scalable cloud processing.

To improve the data used for land cover and land use classification, individual images are combined over short periods. Optical and radar (SAR) images are combined separately to produce monthly composites, or composites covering two months for the period before 2016.

Optical composites reduce or remove the effects of clouds and snow. Annual statistics for the Normalised Difference Vegetation Index (NDVI) complement the monthly spectral composites.

The service first produces a land cover map, which it uses to create a grassland mask. The mask defines the areas analysed by three subsequent components. Grassland Type describes the biological or habitat type, Grassland Management describes management intensity, and Grassland Productivity describes productivity characteristics.

Earth Observation (EO) data were processed on a regular grid of 15 km × 15 km cells covering all Natura 2000 sites included in EU Grassland Watch.

Data from Earth Observation (EO) analyses need to be turned into information that users can interpret in their own context and use to guide management actions or policy development.

An indicator is a variable that represents one or more properties of a habitat or region and is usually derived from one or more datasets. Indicators can summarise the condition of a habitat or region and signal when action may be needed.

The indicators are derived from the annual land cover, grassland permanence, grassland management, and grassland type products.

They are organised into five groups:

• Area: how much grassland there is and what share of the Natura 2000 area it covers, including permanent grassland and its intensively and extensively used parts.
• Fragmentation: how grassland is distributed in patches, measured by patch number, patch density, the size of the largest patch and the distance between patches.

Of particular interest are indicators of grassland abandonment and intensification to track compliance with conservation policies. The key question is whether the N2000 sites are fit for purpose and whether their grasslands are effectively protected. The Directive clearly states that a deterioration of the habitat status is to be avoided.

EU Grassland Watch aims to provide information on the status of and changes in these indicators, making them visible to both expert users and the wider public.

The EU Grasslands Watch platform provides access to the results of the EO-based products and the derived indicators for each of the selected N2000 sites in a clear and dynamic way. It will make this wealth of information fully accessible and understandable to end users.

The key goal is to inform stakeholders and citizens about the context, evolution, and conservation status of specific natural habitat types and species, and the ecological trends of the N2000 network sites across Europe.

The platform displays the results at a range of reporting levels to support stakeholders at local to European scales. Over larger areas, the webtool will show summaries of the indicators and visualisations of hotspots related to both positive and negative performance. The information displayed can be tailored to the specific policy or management question under investigation.

The platform will be updated at regular intervals once fully operational and access to the full time series will be possible.

The platform visualises all the results held in the database including the EO-based products, indicators, and data from other sources. The information will be held on the pixel level appropriate to the source data.

At the site level, the designated area alongside adjacent areas with the 15 km tiles can be visualised to see individual habitat patches and features. The results can be interrogated in a number of ways including plots showing the temporal properties of indicators.

Site managers could use the EU Grassland Watch platform for a wide range of management activities.

For instance, the impacts of historical (post-1990) and current restoration projects could be reviewed to see their value and sustainability over time. In this way, future projects could be better designed and targeted to specific areas and situations to maximise the outcomes.

EU Grassland Watch will help countries (e.g. environment ministries and their agencies) get an overview of the evolution of grasslands at fine spatial resolution since the 1990s. This may be a novel approach for some countries which have not embraced geospatial approaches to monitoring. By offering them EO data processed as standard products, the service helps them to get a more accurate picture of the evolution of their N2000 sites.

Hotspot maps at the EU scale will be used to observe the trends in the losses and degradations of grassland status estimated with the indicators of intensification or abandonment. This information is related to the targets set in the ‘EU Biodiversity Strategy for 2030’, which aims to prevent further degradation in conservation trends and status by 2030. The information on conservation status provided by the EU Grassland Watch will be a vital, first step in supporting the European Green Deal and demonstrating the effectiveness of EO-based decision-making.