CUP4SOIL High-resolution product presentation and data access

Kurzfassung

The CUP4SOIL project aims to develop and test a proof-of-concept for a future downstream service to support national and European agencies in reporting on soil health/quality. One of the objectives of the CUP4SOIL project is to generate European-wide data products and indicators that can be used to characterise soil health and quality. Furthermore, these products, including the input data and environmental covariates used, shall be made available for the user community to test and validate data products and to develop example showcases. This contribution provides an overview about input-products, covariates and soil products including image examples and methodologies. In CUP4SOIL, different data types and levels are used and developed to model soil parameters using the digital soil mapping approach (DSM). DSM uses a statistical model to integrate products derived from Copernicus satellites Sentinel-1 and 2, environmental covariates such as digital elevation models, ERA-5 products and soil ground truth information from the LUCAS survey and other available sources. Several data products are derived from the Sentinel-2 time series using the Soil Composite Mapping Processor (SCMaP). It comprises mean reflectance composites as well as specific soil reflectance composites (SRC) that contain undisturbed and bare soils. Additionally, statistical information about the spectral variability of the soils and the confidence interval (CI) of the SRC spectrum as measure of the quality of the SRC spectrum is given. The bare soil frequency is a measure for the visibility of the bare soil within the whole observed time period in percent. This in an indication for the intensity of use of agricultural fields as well as for the process of soil carbon sequestration. EO based soil products were generated for primary soil properties (SOC, pH, texture), derived soil properties and some basic soil health indicators. The soil observations were split in 10 equally sized folds for cross-validation. Random Forest models were obtained with the ranger package, with the option to build Quantile Random Forests (QRF) to obtain pixel-based uncertainty. In order to allow users to evaluate the usefulness of the products, the SCMaP input products, environmental covariates as well as the final soil parameters are provided at a dedicated webpage with functionalities for downloading and data access via web services. In the future, CUP4SOILS will develop showcases using these data products in order to refine the user requirements for future soil products within the Copernicus Land Monitoring Service.