Geomorphic design and modelling at catchment scale for best mine rehabilitation – The Drayton mine example (New South Wales, Australia)

Abstract

Computer modelling and design tools can assist in environmental management. In particular, post-mining landscapes with large volumes of materials require shaping for optimal erosional stability and ecological and visual integration into the surrounding undisturbed landscape. This paper evaluates the complementary capabilities of landscape evolution modelling (SIBERIA) and geomorphic design software (Natural Regrade with GeoFluv). An existing 11.5-ha waste rock dump (Hunter Valley, New South Wales, Australia) served as the study site. The SIBERIA modelling demonstrated that geomorphic design reduced erosion by half that of conventional designs while being able to store an extra 7% of mine waste volume. Additionally, the spatial pattern of gullying was able to be predicted by modelling, which allowed management in subsequent geomorphic design, and successively more stable patterns. In conclusion, the joint use of the Natural Regrade with GeoFluv geomorphic design software with the SIBERIA landscape evolution model showed complementary capabilities for enhancing mine rehabilitation.This paper is the outcome of a joint research of the three authors, made possible by means of a research stay of J.F. Martín Duque, hosted by G.R. Hancock and G.R. Willgoose, at the University of Newcastle (UoN, Australia). This stay has been funded within a program Estancias de Movilidad de Profesores e Investigadores en Centros Extranjeros de Enseñanza Superior of the Spanish Minister of Education, Culture and Sports (reference PRX16/00441). The authors acknowledge the kind collaboration of the Tom Farrell Institute for the Environment of the UoN. Drayton (AngloAmerican) has kindly supported this research, by providing the GeoFluv-as-built topography, along with all the needed information, which main aim has been getting knowledge in order to develop best mine rehabilitation practises. The assistance of Matt Lord and team is highly appreciated. This manuscript is also a contribution under the joint research of the Ecological Restoration Network REMEDINAL-3 of the Madrid Community (S2013/MAE-2719).Peer reviewe