Publié le 3 mai 2019
One of the main threats for soil degradation is the decline of soil organic carbon—the Copernicus Sentinel-2 satellites are currently being exploited to monitor soil conditions in croplands, in turn supporting the Common Agricultural Policy of the European Union. Soil Organic Carbon (SOC) is a key property for soil quality and food production, as recognised by the European Union, who considers its decline in European soils as one of the main threats for soil degradation.
SOC maps in north-eastern Germany. Soil organic carbon (SOC) maps of a singular field in Demmin (north-eastern Germany), obtained by airborne HySpex (a) and Copernicus Sentinel-2 data (b). On the right hand side (c), the SOC map at regional scale retrieved from Copernicus Sentinel-2 data in the Demmin area.
Copyright: Contains modified Copernicus Sentinel data (2019)/ processed by F. Castaldi et al. 2019
The Sentinel-2 mission of the European Union's Copernicus programme is based on a constellation of two identical satellites that together cover all Earth's land surfaces, large islands, inland and coastal waters every five days at the equator. The mission mainly provides information for agricultural and forestry practices and for helping manage food security. The revisit time of just five days, along with the mission's range of spectral bands mean that changes in soil condition can be more easily monitored. The span of 13 spectral bands, from the visible and the near infrared to the shortwave infrared at different spatial resolutions ranging from 10 to 60 m, takes land and soil monitoring to an unprecedented level.
Funded by BELSPO (the Belgian Federal Science Policy Office), the PROSOIL project team, led by the Earth and Life Institute of the UCLouvain, evaluated the capability of Copernicus Sentinel-2 data for SOC estimation and mapping, in three regions of Belgium, Germany and Luxembourg. These areas were chosen because of presenting different soil characteristics and a considerable variability of SOC content. The PROSOIL team investigated the capability of Copernicus Sentinel-2 bare soil images to map the organic carbon content of the topsoil in croplands. They compared the Copernicus Sentinel-2 results with those obtained using airborne hyperspectral data with higher spatial resolution.
The results highlighted that the spatial resolution of Copernicus Sentinel-2 is adequate to describe SOC variability both at field and regional scale and the prediction accuracy obtained by Copernicus Sentinel-2 data is very similar to that retrieved by airborne hyperspectral data.