Dynamics of geoecological condition of manmade massif and substantiation of transition to predictive control: A case-study of the Unal tailings dam

From the results of the 2022–2026 expedition to the Unal tailings dam, Republic of North Ossetia–Alania, it is found that the reclaimed manmade massif evolves at the rate much higher than the background geological processes have. The annual leveling recorded subsidence values to 2.4 m since 2019 and to 50 cm/year in the center of the object; fractures with an opening depth to 5 m were detected, and local heavings were observed nearby the zones of rainfall infiltration. In the fractures, the volumetric activity of radon reaches 5000 Bq/m³. The research involved testing of a rapid test method of salinity assessment by electrical conductivity of soil and the Ardon river water. The obtained data correlate with the chemical analyses of heavy alkaline metals. The sites of discharge of the mineralized water in the river are revealed. The seismic observations show the change in the spectrum of the microseismic background after an M=4.4 earthquake in November, 2024, which tells about a decrease in the effective hardness of the watered massif. A new integrated approach is proposed, which embraces the deformation, geochemical, radon and seismic parameters. Transition to the stationary predictive control instead of discrete measurements is substantiated for the prediction of hazardous processes and prompt protective decision-making. The global significance of monitoring of suspended tailings dams in the context of the induced emergency prevention is emphasized. 

Fomenko V. A., Rudnitsky D. Y., Plakhotin D. A., Bashmashnikov I. I., Kovalev G. S. Dynamics of geoecological condition of manmade massif and substantiation of transition to predictive control: A case-study of the Unal tailings dam. MIAB. Mining Inf. Anal. Bull. 2026;(11):95-105. [In Russ]. DOI: 10.25018/0236_1493_2026_11_0_95.

The study was carried out at the Southern Federal University and supported by the Russian Science Foundation, Projects Nos. RNF/23-37-GL and 23-77-00015.

V.A. Fomenko¹, Cand. Sci. (Eng.), Assistant Professor, Senior Researcher, e-mail: vafomenko@sfedu.ru, ORCID ID: 0000-0003-4725-3673,
D.Y. Rudnitskiy, Managing Director, Joint-Stock Company «Southern Scientific & Production Association for Marine Geological Explorations», e-mail: rudnitskiydy@rusgeology.ru, ORCID ID: 0009-0002-4917-1049,
D.A. Plakhotin¹, Assistant, Branch of Southern Federal University in Gelendzhik, Gelendzhik, Russia, e-mail: plakhotin@sfedu.ru, ORCID ID: 0009-0005-5329-6903, 
I.I. Bashmashnikov¹, Assistant, Branch of Southern Federal University in Gelendzhik, Gelendzhik, Russia, e-mail: bash@sfedu.ru, ORCID ID: 0009-0009-5440-2850,
G.S. Kovalev, Student, North Caucasus Mining and Metallurgical Institute (State Technological University), Vladikavkaz, North Ossetia—Alania, Russia, e-mail: georkovalev@mail.ru, ORCID ID: 0009-0005-6016-0545,
¹ Southern Federal University, branch of the Southern Federal University in Gelendzhik, Gelendzhik, Russia. 

D.A. Plakhotin, e-mail: plakhotin@sfedu.ru.

1. Fomenko V. A., Sokolov A. A., Lolaev A. B., Bashmashnikov I. I., Turmetova G. Z. Evolution of deformations inside reclaimed man-made object of mining practice. MIAB. Mining Inf. Anal. Bull. 2025, no. 7, pp. 90—101. [In Russ]. DOI: 10.25018/0236_1493_2025_7_0_90.

2. Klyuev R. V. Geoecological aspects and environmental technologies in gold cyanidation at gold recovery plants. MIAB. Mining Inf. Anal. Bull. 2026, no. 3, pp. 5—17. [In Russ]. DOI: 10.25018/0236_1493_2026_3_0_5.

3. Seryanina A. V., Ovchinnikova T. I., Tertychnaya S. V. On the issue of environmental safety in the metallurgical industry. Occupational Safety in Industry. 2024, no. 8, pp. 23—28. [In Russ]. DOI: 10.24000/0409-2961-2024-8-23-28.

4. Fomenko V. A., Makovozova Z. E., Sokolov A. A., Aksenova M. A., Kovalev G. S. Analysis of water conditions and evolution of rock mass at a mining industry object after reclamation. MIAB. Mining Inf. Anal. Bull. 2025, no. 5, pp. 118—129. [In Russ]. DOI: 10.25018/0236_1493_2025_5_0_118.

5. Rico M., Benito G., Salgueiro A. R., Díez-Herrero A., Pereira H. G. Reported tailings dam failures: A review of the European incidents in the worldwide context. Journal of Hazardous Materials. 2008, vol. 152, no. 2, pp. 846—852.

6. Kossoff D., Dubbin W. E., Alfredsson M., Edwards S. J., Macklin M. G., Hudson-Edwards K. A. Mine tailings dams: Characteristics, failure, environmental impacts, and remediation. Applied Geochemistry. 2014, vol. 51, pp. 229—245.

7. Chen J., Li K., Chang K. J., Sofia G., Tarolli P. Open-pit mining geomorphic feature characterisation. International Journal of Applied Earth Observation and Geoinformation. 2015, vol. 42, pp. 76—86.

8. Liu Z., Cao W., Zhang C., Li H., Zhang Y. Machine learning-based prediction of tailings dam stability. Advances in Civil Engineering. 2021, vol. 2021, article 6627964.

9. Kulikova E. Yu., Balovtsev S. V., Skopintseva O. V. Geoecological monitoring during mining operations. Sustainable Development of Mountain Territories. 2024, vol. 16, no. 2, pp. 580—588. [In Russ]. DOI: 10.21177/1998-4502-2024-16-2-580-588.

10. Vurdova N. G., Ovchinnikova T. I., Tertychnaya S. V., Kulikova A. A., Meshchanova V. D., Vurdov P. Y., Birman Y. A., Krotova M. V., Yakusheva A. A. An innovative technical solution for the extraction and disposal of hazardous industrial waste for landfill decommissioning. Environments. 2026, vol. 13, no. 5, article 272. DOI: 10.3390/environments13050272.

11. Zemlyanoy M. A., Gabaraev O. Z., Dovgal V. V., Sakhnov A. V. Geomechanical zoning of aged tailings at the urup tailings storage facility as a basis for differentiated processing and backfilling. Sustainable Development of Mountain Territories. 2026, vol. 18, no. 1, pp. 157—176. [In Russ]. DOI: 10.21177/1998-4502-2026-18-1-157-176.

12. Shepelev I. I., Pilyaeva O. V., Sokolov A. A., Adam A. M., Nemerov A. M. Development of engineering solutions for industrial wastewater treatment of alumina production. Ecology and industry of Russia. 2025, vol. 29, no. 12, pp. 10—14. [In Russ].

13. Svobodova K., Barták V., Hendrychová M. Visiting mine reclamation: How field experience shapes perceptions of mining. Ambio. 2025, vol. 54, pp. 72—85. DOI: 10.1007/s13280-024-02055-y.

14. Basu D., Mishra S. Mine reclamation practices and effects of stakeholder perception — A case study of Saoner mines, Maharashtra, India. Journal of Engineering and Applied Sciences. 2024, vol. 71, article 62. DOI: 10.1186/s44147-024-00393-y.

15. Dusengemungu L., Mubemba B., Gwanama C. Evaluation of heavy metal contamination in copper mine tailing soils of Kitwe and Mufulira, Zambia, for reclamation prospects. Scientific Reports. 2022, vol. 12, article 11283. DOI: 10.1038/s41598-022-15458-2.

16. Mukumba C. P., Sishekanu M., Marais L. Mine waste disasters on the Zambian Copperbelt: Regulatory and community concerns. Environmental Management. 2026, vol. 76, article 143. DOI: 10.1007/s00267-026-02444-x.

17. Wang S., Guo J., Yu Y., Shi P., Zhang H. Quality evaluation of land reclamation in mining area based on remote sensing. International Journal of Coal Science & Technology. 2023. vol. 10, article 43. DOI: 10.1007/s40789-023-00601-9.

18. Ali M. A. H., Qian W., Rabeiy R., Saleem H. A., Mohamed A. S., Muhammad A. U., Shebl A. Environmental impact assessment of leachate from mining tailings using electrical resistivity imaging. Scientific Reports. 2025, vol. 15, article 23671. DOI: 10.1038/s41598-025-08030-1.

19. Ledesma J., Neilson J. W., Maier R. M., Babst-Kostecka A., Rasmussen C. Effects of stockpiling on topsoil biogeochemistry for semiarid mine reclamation. Mining, Metallurgy & Exploration. 2025, vol. 42, pp. 15—26. DOI: 10.1007/s42461-024-01164-2.

20. Mohuba S. C., Moshipya P. M., Abiye T. A., Nhleko S., Korir I. Radionuclide distribution and exposure doses in mine tailing dumps from the west rand gold mining region of the Gauteng province, South Africa. Discover Environment. 2025, vol. 3, article 213. DOI: 10.1007/s44274-025-00430-4.

21. Sahakyan S., Yedoyan T., Khachatryan E., Hakobyan M., Gevorgyan A. Reclamation of saline-sodic heavy-textured soils using a novel electro-reclamation method. Journal of the Saudi Society of Agricultural Sciences. 2026, vol. 25, article 35. DOI: 10.1007/s44447-026-00142-y.

22. Girón-Guzmán I., Sánchez-Alberola S., Cuevas-Ferrando E., Falcó I., Díaz-Reolid A., Puchades-Colera P., Ballesteros S., Pérez-Cataluña A., Coll J. M., Núñez E., Fabra M. J., López-Rubio A., Sánchez G. Longitudinal study on the multifactorial public health risks associated with sewage reclamation. Clean Water. 2024, vol. 7, article 72. DOI: 10.1038/s41545-024-00365-y.