SoilSuite Europe

Abstract

Based on a recent study of JRC and EEA, about 63% of the European soils are degraded (Arias-Navarro et al., 2024). Therefore, the European Union’s Soil Strategy 2030 and Horizon Europe’s Mission “A Soil Deal for Europe” has been developed. Furthermore, the European Commission intensifies efforts to develop reliable and robust soil monitoring strategies. There is a high demand for information about chemical and physical properties of European soils, properties that can reflect the consequences of our intensive use of the natural resource soil.

Earth Observation (EO) is a valuable data source for large scale information about the Earth surface. In the CUP4Soil project, EO-based and European-wide soil information has been developed with the objective to provide it to a large user community and to prepare the ground for the extension of the Copernicus Land Monitoring Service by soil related information. In this presentation, the SoilSuite, a collection of different image data products for Europe, is presented. It leverages the Sentinel-2 data archive that is assimilated by DLR’s Soil Composite Mapping Processor (SCMaP), a specific processing chain for detecting and analyzing bare soil surfaces on a large (continental) scale. The methodology behind SCMaP is constantly enhanced using a technique that allows to control the variation of the different processing parameters or concepts (presented by a LPS submission from Karlshöfer et al.).

We present a variety of pixel-based spectral information products of bare soils. The “Bare Surface Reflectance Composite – Mean” shows distinct spectral properties of soils due to varying soil organic carbon (SOC) content, soil moisture and soil minerology. Additionally, the product “Bare Surface Reflectance Composite - Standard deviation” informs about the spectral dynamic of soils that is an rarely used characteristic. An important milestone is the provision of a data product to inform users about the reliability of the spectral information. Thus, we developed the “Bare Surface Reflectance Composite – 95% Confidence” product. It contains the half width of the 95% confidence interval (CI) of the “Bare Surface Reflectance Composite”. Finally, the “Bare Surface Frequency Product” is scaled between 0 and 1 and quantifies the number of bare soil occurrences over the total number of valid observations. It highlights areas with limited soil coverage by e.g. vegetation. It is a generic product that can be used to identify areas that have been prone to soil erosion. Further, the “Bare Surface Frequency” can be used to better distinguish between areas with carbon farming and those with conventional agriculture.

All products are used for the SOC map of the WorldSoils project as well as for the mapping of chemical/physical soil properties and uncertainties developed during the CUP4SOIL project (presented by a LPS submission from Poggio et al.). We further explored the suitability of the “Bare Surface Frequency Product” for the assessment of potential soil erosion source areas of river basins using the variety of products of HYDROSHEDS (HYDROSHEDS, access: 11/2024).

Finally, it is important to enable the access of the SoilSuite on free and open access conditions to allow users to test and experience the data by their own. The direct EO-based data (https://doi.org/10.15489/qkud8cudg596) can be accessed soon via DLR’s EOC Geoservice and the EO-based information as well as the soil properties and their uncertainties are available via a dedicated website of ISRIC. Both platforms provide functionalities for data visualization (via OGC-WMS) as well as data download (CC BY 4.0 license).