DOI https://doi.org/10.36487/ACG_repo/2215_06
Cite As:
Hancock, G & Martín Duque, JF 2022, 'Assessing the stability of a geomorphically reconstructed post-mining landscape: a case study of the Santa Engracia mine, Spain', in AB Fourie, M Tibbett & G Boggs (eds),
Mine Closure 2022: Proceedings of the 15th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 127-142,
https://doi.org/10.36487/ACG_repo/2215_06
Abstract:
New technology allows for the reconstruction of post-mining landforms using geomorphic design principles. It is important that such designs be evaluated and, if needed, be reshaped so that soil loss is minimised and they geomorphologically and ecologically integrate with the surrounding landscape. One method to assess geomorphic landform designs is to use a computer-based landscape evolution model. Landscape evolution models allow different designs to be input and will highlight where erosion will occur and the type of erosion (i.e. sheetwash, rilling, gullying) as well as erosion rate. At the Santa Engracia abandoned mine (East-Central Spain), post-mining landscapes were designed and constructed using geomorphic principles (GeoFluv method and Natural Regrade software). In this design process, the SIBERIA landscape evolution model has been used to assess the erosional behaviour of these landscapes. Results demonstrate that some gullying is inevitable. Using suitable topsoil, vegetation and an organic blanket will dramatically reduce erosion, and if vegetation can be established, the modelling demonstrates that the landscapes will have minimal erosion. The erosion forecast is 5.3–15.2 t ha-1 yr-1, an order of magnitude less than the initial erosion rate (~350 t ha-1 yr-1) using conventional (terraced) mine restoration. Further, the erosion rates and localised gullying approximate the unmined (natural) Alto Tajo environment. Importantly, with the ability to spatially forecast gully location, erosion reduction measures can be undertaken. Consequently, the method described here provides a robust assessment procedure that can be used at other sites and highlights the potential strengths and weakness of a design process, therefore supporting lower cost with a higher chance of restoration success. The combination of geomorphic landform design and assessment using a landscape evolution at this project presents a new standard for mine rehabilitation in Europe.
Keywords: geomorphic landform design, geomorphic restoration, GeoFluv, SIBERIA, gully
References:
Ahnert, F 1976, ‘Brief description of a comprehensive three-dimensional model of landform development’, Z. Geomorphol Supplement Band, vol. 25, pp. 29–49.
Bugosh, N & Eckels, R 2006, ‘Restoring erosional features in the desert’, Coal Age, vol. 111, no. 3, pp. 30–32.
Bugosh, N & Epp, E 2019, ‘Evaluating sediment production from native and fluvial geomorphic reclamation watersheds at La Plata Mine’, Catena, vol. 174, pp. 383–398,
Coulthard, TJ, Hancock, GR & Lowry JBC 2012, ‘Modelling soil erosion with a downscaled landscape evolution model’, Earth Surface Processes and Landforms, vol. 37, pp. 1046–1055.
FAO 1988, Sistemas de labranza para la conservación del suelo y del agua (Tillage systems for soil and water conservation), FAO, Roma.
Hancock, GR, Coulthard, TJ & Lowry JBC 2016, ‘Predicting uncertainty in sediment transport and landscape evolution - the influence of initial surface conditions’, Computers & Geosciences, vol. 90, pp. 117–130.
Hancock, GR & Willgoose GR 2018, ‘Sustainable mine rehabilitation – 25 years of the SIBERIA landform evolution and long-term erosion model’, From Start to Finish: A Life-Of-Mine Perspective, Australasian Institute of Mining and Metallurgy, Melbourne.
Kirkby, MS 1971, ‘Hillslope process-response models based on the continuity equation’, Slopes: Form and Process, serial publication 3, Institute of British Geographers, London, pp. 15–30.
Martín Duque, JF, Tejedor, M, Martín-Moreno, C, Nicolau JF, Sanz Santos, MA, Sánchez Donoso, R & Gómez Díaz, JM 2020, ‘Geomorphic landscape design integrated with progressive mine restoration in clay quarries of Catalonia’ International Journal of Mining, Reclamation and Environment, vol. 35, no. 6, pp. 399–420.
Martín Duque, JF, Zapico, I, Bugosh, N, Tejedor, M, Delgado, F, Martín-Moreno, C & Nicolau, JM 2021, ‘A Somolinos quarry land stewardship history: From ancient and recent land degradation to sensitive geomorphic-ecological restoration and its monitoring’, Ecological Engineering, vol. 170, no. 106359.
Martín-Moreno, C, Martín Duque, JF, Nicolau, JM, Muñoz, A & Zapico, I 2018, ‘Waste dump erosional landform stability – a critical issue for mountain mining’, Earth Surface Processes and Landforms, vol. 43, pp. 1431–1450.
Orman, M, Peevers, R & Sample, K 2011, ‘Waste piles and dumps’, P Darling (ed.), SME Mining Engineering Handbook, Society of Mining Engineering, Englewood, pp. 667–680.
Schmidt, BL, Allmaras, RR, Mannering, JV & Papendick RI 1982, ‘Determinants of soil loss tolerance’, American Society of Agronomy, Soil Science Society of America, Madison.
Tucker, G & Hancock, GR 2010, ‘Modelling landscape evolution’, Earth Surface Processes and Landforms, vol. 35, pp. 28–50.
Willgoose, GR 2018, Principles of Soilscape and Landscape Evolution, Cambridge University Press, Cambridge.
Zapico, I, Martín Duque, JF, Bugosh, N, Laronne, JB, Ortega, A, Molina, A, … & Sánchez, L 2018, ‘Geomorphic reclamation for reestablishment of landform stability at a watershed scale in mined sites: the Alto Tajo Natural Park, Spain’, Ecological Engineering, vol. 111, pp. 100–116.
Zapico, I, Molina, A, Laronne, JB, Sánchez Castillo, L& Martín Duque, JF 2020, ‘Stabilization by geomorphic reclamation of a rotational landslide in an abandoned mine next to the Alto Tajo Natural Park’, Engineering Geology, vol. 264, no. 105321,