Integrated multispectral and hyperspectral remote sensing for mapping metal contamination in the São Domingos mining area (southern Portugal)

The São Domingos Mine (southern Portugal) is an abandoned sulphide mining area where metal contamination extends over approximately 20 km along a watercourse connected to a reservoir and two international rivers. Conventional soil contamination assessment relies on extensive field sampling and laboratory analysis, both of which are time-consuming and spatially limited.

Within the INCOME project (Inputs for a more sustainable region – Instruments for managing metal-contaminated areas), satellite-based remote sensing is explored as a means to parametrise the study area at a spatial resolution of approximately 30 m, helping to overcome the spatial limitations inherent to point-based laboratory measurements.
Multispectral and hyperspectral satellite data, including Sentinel-2 MSI, EnMAP and PRISMA observations, are used to characterise metal-contaminated surfaces. This combines the high spatial and temporal coverage of the MSI with the enhanced spectral resolution of the hyperspectral sensors, which is essential for identifying the absorption features associated with metals. Atmospheric correction based on radiative transfer modelling (6SV) ensures consistent surface reflectance products, and machine learning techniques are employed to correlate satellite-derived information with laboratory measurements of specific metals. Overall, this work presents the potential of integrated remote sensing approaches in supporting the more efficient monitoring and management of metal-contaminated areas.

Acknowledgments: The work is supported by the Promove Program of the “la Caixa” Foundation, in partnership with BPI and the Foundation for Science and Technology (FCT), in the scope of the project INCOME – Inputs para uma região mais sustentável: Instrumentos para a gestão de zonas contaminadas por metais (Inputs for a more sustainable region: Instruments for managing metal-contaminated areas), PD23-00013, and by national funds through FCT, in the framework of the UID/06107/2025 – Centro de Investigação em Ciência e Tecnologia para o Sistema Terra e Energia (CREATE – University of Évora), and in the frame of UID/00073/2025 and UID/PRR/00073/2025 projects of the R&D unit of Geosciences Center (University of Coimbra, Portugal).