Lowry, JBC, Saynor, MJ, Hancock, G & Coulthard, TJ 2022, 'A catchment-scale comparison of field observations of a constructed landform with erosion predictions from a landscape evolution model', 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. 1169-1178, https://doi.org/10.36487/ACG_repo/2215_86
Rehabilitation has commenced at the Ranger uranium mine in the Northern Territory of Australia. The Ranger rehabilitated landform is required to contain tailings material for a period of at least 10,000 years, and to produce erosion rates that eventually correspond with those of the surrounding undisturbed landscape. Landscape evolution models (LEMs) provide a means of predicting how a rehabilitated landform may evolve over extended periods of time. In this study, we utilised optical imagery acquired from remotely piloted aircraft (RPA), and ground-based observations to identify gully/drainage line development on the newly constructed Pit 1 landform over the period from 2020 to 2021. The Pit 1 landform encompasses an area of approximately 40 hectares and is the first part of the Ranger landform to be rehabilitated. We compare these observations with predictions from the CAESAR-Lisflood LEM of gully development over the same 12-month period. This work builds on earlier work undertaken to calibrate the CAESAR-Lisflood model at an erosion plot scale on the Ranger mine and applies it at a larger spatial scale. Over the one-year period, the model was able to predict the development of drainage lines in similar places to those observed via imagery and on-ground observations on the constructed Pit 1 landform. While acknowledging the limitations of a study of only 12 months duration, the results here provide confidence that the parameters used in the model are appropriate for predicting gully erosion at the larger catchment scale of this study, and that the results are relevant for extended time periods.
Keywords: erosion, landform, modelling, drones
Coulthard, TJ 2019, CAESAR Sensitivity Analysis, unpublished report for the Supervising Scientist Branch, Department of the Environment and Energy.
Coulthard, TJ, Neal, JC, Bates, PD, Ramirez, J, de Almeida, GAM & Hancock, GR 2013, ‘Integrating the LISFLOOD-FP 2D hydrodynamic model with the CAESAR model: implications for modelling landscape evolution’, Earth Surface Processes and Landforms,
Hancock GR, Coulthard TJ & Lowry JBC 2016, ‘Predicting uncertainty in sediment transport and landscape evolution – the influence of initial surface conditions’, Computers and Geosciences, vol. 90, pp. 117–130.
Hancock, GR, Lowry, JBC, Coulthard, TJ, Evans, KG & Moliere, DR 2010, ‘A catchment scale evaluation of the SIBERIA and CAESAR landscape evolution models’, Earth Surface Processes and Landforms, vol. 35, pp. 863–875.
Hancock, GR, Saynor, M, Lowry, JBC & Erskine WD 2020, ‘How to account for particle size effects in a landscape evolution model when there is a wide range of particle sizes’, Environmental Modelling and Software, vol. 124, no. 104582,
Lowry, JBC, Coulthard, TJ & Hancock, GR 2013, ‘Assessing the long-term geomorphic stability of a rehabilitated landform using the CAESAR-Lisflood landscape evolution model’, in M Tibbett, AB Fourie & C Digby (eds), Mine Closure 2013: Proceedings of the Eighth International Seminar on Mine Closure, Australian Centre for Geomechanics, Cornwall, pp. 611–624,
Lowry, JBC, Coulthard, TJ, Hancock, GR & Jones, DR 2011, 'Assessing soil erosion on a rehabilitated landform using the CAESAR landscape evolution model ©', in AB Fourie, M Tibbett & A Beersing (eds), Mine Closure 2011: Proceedings of the Sixth International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 613–621,
Lowry, J, Coulthard, T, Saynor, M & Hancock, G 2020, A Comparison of Landform Evolution Model Predictions With Multi-Year Observations From a Rehabilitated Landform, internal Report 663, Supervising Scientist, Darwin.
Lowry, J, Saynor, M, Erskine, W, Coulthard, T & Hancock, G 2014, ‘A multi-year assessment of landform evolution model predictions for a trial rehabilitated landform’, Proceedings of the Life of Mine Conference 2014, The Australasian Institute of Mining and Metallurgy, Melbourne, pp. 67–80.
McQuade, CV, Arthur, JT & Butterworth, IJ 1996, ‘Climate and hydrology’, in CM Finlayson & I von Oertzen (eds) Landscape and Vegetation of the Kakadu Region, Northern Australia, Kluwer Academic Publishers, Dordrecht, pp. 17–35.
Moliere, DR, Evans, KG, Willgoose, GR & Saynor, MJ 2002, Temporal trends in erosion and hydrology for a post-mining landform at Ranger Mine, Northern Territory, Supervising Scientist, Darwin.
Saynor, MJ, Lowry, JBC & Boyden, JM 2019, ‘Assessment of rip lines using CAESAR-Lisflood on a trial landform at the Ranger uranium mine’, Land Degradation and Development,
Saynor, MJ, Lowry, J, Erskine, WD, Coulthard, T, Hancock, G, Jones, D & Lu, P, 2012, ‘Assessing erosion and run-off performance of a trial rehabilitated mining landform’, Proceedings of the Life of Mine Conference 2012, The Australasian Institute of Mining and Metallurgy, Melbourne
Supervising Scientist Division 1999, Environmental Requirements for the Ranger Uranium Mine, Department of Sustainability, Environment, Water, Populations and Communities, Supervising Scientist Division, Darwin,
Temme, AJAM, Schoorl, JM & Vedkamp, A 2006, ‘Algorithm for dealing with depressions in dynamic landscape evolution models’, Computers and Geosciences, vol. 32, no. 4, pp. 452-461.
Wasson, RJ, Saynor MJ & Lowry, JBC 2021, ‘The natural denudation rate of the lowlands near the Ranger mine, Australia: A target for mine site rehabilitation’, Geomorphology, vol. 389,
Wilcock, PR & Crowe, JC 2003, Surface-based transport model for mixed-size sediment, Journal of Hydraulic Engineering, vol. 129, pp. 120–128.