Geophysical and geospatial characterization of mining heaps of the São Domingos Mine (Mértola, Portugal)

The São Domingos Mine (Mértola, Portugal) is an abandoned sulphide mine whose exploitation has had a long-term impact on its soil and water contamination problem covering an area of ​​approximately a length of 20 km and a width of 2 km. The mining heaps are spread along a watercourse that flows into the Chança River dam, which merges with the Guadiana River, both international rivers. This constitutes a serious environmental problem leading to contamination by heavy metals (HMs). Contamination assessment is a slow process that involves collecting soil samples for HMs analysis.

The study of mining heaps using geophysical and geospatial methods allows us to determine their depth and the volume of accumulated materials, as well as their characterization in relation to soils contaminated by HMs. We propose the use of electromagnetic induction, electrical resistivity tomography and GNSS methods to carry on the analysis.

This work is part of an interdisciplinary study that is being carried out within the scope of the INCOME Project (Inputs for a more sustainable region – Instruments for managing metal-contaminated areas). The aim is to combine data from Geophysics, Chemistry and Remote Sensing to create a tool, using Artificial Intelligence, that allows the calculation of contamination maps using less data than standard methodologies.

This is a sustainable management model that will increase optimization and reduce resources spent in the sampling and analysis phases. Moreover, the model aims to provide important real-time information for decision-making subjected to monitoring and managing pollution. It also has a high replication potential for other contaminated environments, such as landfills, industry or even intensive agriculture.

Funding: The work was 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. Acknowledgment: CREATE Project (R&D Unit ID 6107).