An international vocabulary for anthropogenic deposits to improve geological mapping and modelling

Anthropogenic deposits are widespread in various environments. Some consist of displaced natural materials, and others of anthropogenic (human-made) materials, or they contain a mixture of both. Human-made materials include demolition materials (such as concrete), industrial waste and by-products (e.g., slags), mining residues, and domestic waste. Excavated soils and dredged sediments are examples of displaced natural materials. Anthropogenic deposits can be linked to hazards like geotechnical instability and contamination, potentially resulting in health and environmental risks (e.g., to soil, water, biodiversity, stable site foundation) with associated economic, legal, and social impacts. On the other hand, some deposits can represent valuable resources. Former mining or urban deposits, for example, may contain extractable amounts of critical raw materials (CRM). They may also be reused during land development or hold geoheritage value, such as in the case of prehistoric burial constructions. However, our knowledge of anthropogenic deposits is still poor. Improving their representation in geological maps and models is therefore crucial. Against this background, the European GSEU project is developing a set of coordinated vocabularies to standardise the describtion of anthropogenic deposits.

Existing national and international vocabularies and definitions were collected and compiled into a comprehensive list. In parallel, a conceptual data model was developed as a basis to systematically organise and classify the terms. This allowed establishing hierarchical lists of terms to structure the vocabularies and provide space for additional information on anthropogenic deposits, such as their purpose and geometry. A coherence and consistency check between the various vocabulary lists was conducted to ensure alignment across all terms. Real-world examples (use cases) of anthropogenic deposits were used to test the effectiveness and relevance of the vocabularies.

A “lithology-based” approach was chosen to describe anthropogenic deposits. The terms for displaced natural materials originate from the lithology vocabulary, which is being compiled in parallel within the GSEU project. For human-made materials an existing classification from materials science is used, with some adaptations and additions. The set of vocabularies includes additional attribute lists linked to the origin of the materials present in the deposit, the original purpose of the deposit, the shape of the deposit, as well as its environment (natural, anthropic). The selected use cases cover various situations (former landfill, redevelopment area, archaeological site, mine tailing, industrial residue, reclaimed land) in several environments (urban, rural, mining, industrial, coastal and fluvial environment). The associated environmental and social issues include sanitary aspects linked to soil pollution, surficial and groundwater quality, geotechnical stability (vulnerability to collapse, landslide, ground subsidence, erosion, etc.), and cultural heritage.

The developed scientific vocabularies dedicated to anthropogenic deposits are designed for use with multiscale spatial geological datasets in both 2D and 3D formats. These can be integrated within geological maps and 3D models to support various applications, such as spatial planning, area development, resource extraction, and risk management. The final hierarchical lists of terms will be delivered for implementation in EGDI, the European platform to share, integrate and access geological data.