Integrated Model for the Assessment and Prioritisation of Environmental Risks Associated with Inactive Tailings Dumps in the Jiu Valley

Abstract

Tailings dumps in post-mining coalfield regions may represent persistent sources of pressure on soils, surface waters, the landscape and local communities. In the Jiu Valley, the regional inventory comprises 49 tailings dumps, of which 26 are rehabilitated, 9 are active and 14 are inactive. This study develops and applies a Synthetic Risk Index (ISR) to all 14 inactive dumps by integrating three components: the integrated geochemical index (IG), the morphometric index (IM – area and volume) and the site vulnerability index (IV – proximity to water bodies and settlements, wind exposure and sensitive land uses). The geochemical component was calculated using the common set of metals Cr(total), Cu and Ni, available for all sites, based on values determined at sampling points P1–P17 in 2023. The model uses min–max normalisation and a weighted scheme in which geochemical pressure is the main component, while physical size and spatial vulnerability act as risk-amplifying factors. The results indicate that the Ramura 1–4 Petrila, Defor, Balomir, Funicular Vechi, Bloc 0 and Ramura 1–2 dumps fall within the high-risk class, whereas the remaining sites are distributed between the moderate- and low-risk classes. The proposed model provides a regional screening tool that is useful for prioritising the monitoring, stabilisation and ecological rehabilitation of inactive dumps, with potential for subsequent integration into a GIS-based decision-support framework.