Identifying soil sealing hotspots on-demand for reporting and decision making in Austria using a Sentinel-2 based semantic EO data cube

Soil sealing, the process of covering ground with impermeable material, is one of the main causes of land degradation in the European Union. Thus, reducing the ongoing human-induced (artificial) soil sealing and to achieve land degradation neutrality is of high community interest, since soil sealing threatens the availability of fertile soils and groundwater reservoirs for future generations. To meet the goals for a reduction in land degradation, a repeated and spatially explicit monitoring of soil sealing is crucial for reporting (e.g. on UN SDG 15.3.1), decision support, as well as spatial management and planning. However, an elaborated approach for a systematic up-to-date area-wide assessment of soil sealing and related indicators for reporting are still not available.
Earth observation (EO) satellite data are a valuable data source for monitoring approaches, since large areas can be regularly covered with a ground sampling distance (GSD) up to decimetres (cf. very high resolution (VHR) satellite imagery). Compared to VHR satellite imagery the Copernicus Sentinel-2 data offers a lower spatial resolution (up to 10 m),but are cost-free and captured regularly with an acquisition frequency of 3-5 days. The dense time series of observations, such as provided by the Sentinel-2 mission, are a key requirement for the production of reliable up-to-date information products enabling the continuous monitoring of land surface changes.
The recently started project “Soil sealing identification and monitoring system” aims to evaluate the suitability of Sentinel-2-based soil sealing detection in Austria using the worldwide unique semantic EO data cube (Sen2Cube.at) and how it can be improved for the usage in reporting, decision support, as well as spatial management and planning on national- and provincial level. The project goals are the following. 1) Enable Austrian public authorities to use free and open multi-temporal Copernicus Sentinel-2 imagery and to integrate it into their daily workflows. 2) Identify and monitor soil sealing in respect to the spatial and temporal resolution of Sentinel-2, provide it as on-demand solution and use it as complementary methodology to enrich existing information. 3) Facilitate non EO-experts to develop and conduct custom multi-temporal (inter- and intra-annual) EO-based analysis using semantic enriched EO data.
Soil continues to be sealed and advances in data acquisition (e.g. Copernicus) and infrastructure technology (e.g. cloud-based systems, EO data cubes) have changed what can be regularly identified and monitored, but the analytical workflows and daily operational workflows for assessing soil sealing have not yet adapted to these advances. The SIMS project with the aim of a prototypical implementation serves as an initial stepping-stone addressing the discussed issues and bringing national and provincial authorities closer to up-to-date EO-based solutions for monitoring soil sealing tailored to their needs.