Restoring earth surface processes through landform design. A 13‐year monitoring of a geomorphic reclamation model for quarries on slopes

Abstract

The application of geomorphic principles to land reclamation after surface mining has been reported in the literature since the mid-1990s, mostly from Australia, Canada and the USA. This paper discusses the reclamation problems of contour mining and quarries on slopes, where steep gradients are prone to both mass movement and water erosion. To address these problems simultaneously, a geomorphic model for reclaiming surface mined slopes is described. Called the 'highwall-trench concave slope' model, it was first applied in the 1995 reclamation of a quarry on a slope (La Revilla) in Central Spain.The geomorphic model does not reproduce the original topography, but has two very different sectors and objectives: (i) the highwall-trench sector allows the former quarry face to evolve naturally by erosion, accommodating fallen debris by means of a trench constructed at the toe of the highwall; (ii) the concave-slope base sector, mimicking the landforms of the surrounding undisturbed landscape, promotes soil formation and the establishment of self-sustaining, functional ecosystems in the area protected from sedimentation by the trench. The model improves upon simple topographic reconstruction, because it rebuilds the sutficial geology architecture and facilitates re-establishment of equilibrium slopes through the management and control of geomorphic processes.Thirteen years of monitoring of the geomorphic and edaphic evolution of La Revilla reclaimed quarry confirms that the area is functioning as intended: the highwall is backwasting and material is accumulating at the trench, permitting the recovery of soils and vegetation on the concave slope. However, the trench is filling faster than planned, which may lead to run-off and sedimen tation on the concave slope once the trench is full. The lesson learned for other scenarios is that the model works well in a two dimensional scheme, but requires a three-dimensional drainage management, breaking the reclaimed area into several watersheds with stream channels.

Quantification and analysis of geomorphic processes on a recultivated iron ore mine on the Italian island of Elba using long-term ground-based lidar and photogrammetric SfM data by a UAV

“…Especially in the Mediterranean regions, the climatic conditions in combination with the topography and the lithology lead to intensive gullying and bad land generation (Della Seta et al, 2009;Aucelli et al, 2012), with high intensities on steep and barely vegetated slopes (Haas et al, 2011). The geomorphic process dynamic, including hazards, can be intensified by anthropogenic influences, such as deforestation for agricultural utilization (Aucelli et al, 2012) or major changes e.g., by mining (Nowotny, 2003;Martín-Duque et al, 2010;Mossa and James, 2013). Especially mining sites in hilly or mountainous regions can show steep and mostly anthropogenically created slopes (also due to a recultivation) without natural soils and changed hydrological conditions influencing surface hydrology, flow paths, and groundwater level (Osterkamp and Joseph, 2000).…”

13.6 Impacts of Mining on Geomorphic Systems

“…Use of geomorphic principles to understand mined land reclamation is relatively recent, as early efforts at land reclamation commonly created a distinctive landform suite (Haigh, 1978). Reclamation generally does not reestablish the original topography, but aims to reduce off-site impacts and promote soil formation and the establishment of self-sustaining functional ecosystems through the management and control of geomorphic processes (e.g., Martín-Duque et al, 2010). Sometimes, there are many more water bodies on the landscape than had been originally present.…”

A descriptive and quantitative approach regarding erosion and development of landforms on abandoned mine tailings: New insights and environmental implications from SE Spain

“…Thus, this dynamic geomorphic procedure tackles most of the erosion-related problem because it essentially reproduces the natural landform evolution to the mature stage, resulting in stable slopes and channels in balance with the local environmental conditions (Martín-Duque et al, 2010). This reflection means also that the hydrological connectivity of minescapes with their surrounding is not the problem per se.…”