Soil Quality Assessment in European Mining and Quarrying: a Novel Tiered Approach

This thesis was developed within the framework of the Soil Survey and Health Conservation Management Plan (SSHCMP), the methodological guide proposed by the European ROTATE project for the sustainable management of soils in mining and quarrying sites. The work focuses on the application and testing of a functional soil quality assessment model, designed to evaluate the ecological condition of soils throughout the entire mining cycle, from pre-extraction to post-rehabilitation. The evaluation system is based on seven soil functions and is structured in two tiers of application: Tier 1, which uses only topsoil data, and Tier 2, which incorporates information from the full soil profile. The thesis presents a detailed methodology for selecting descriptors, calculating function scores, and interpreting results. The model was tested using a combination of natural soils from European datasets (LUCAS and ESDAC) and contaminated soils from a former arsenic–copper mine in northern Spain. Comparisons were carried out to evaluate both the model’s capacity to detect differences between natural and degraded soils and the consistency between Tier 1 and Tier 2 outputs. The results show that Tier 1, despite its simplified nature, provides coherent and conservative results when compared to Tier 2. The model successfully identified key differences in soil functionality between degraded and non-degraded contexts, confirming its potential as a tool for diagnosis, monitoring, and support to decision- making in soil restoration efforts in mining environments.