Evaluating Erosional Stability of Reconstructed Mine Landscapes Using Landform Evolution Models: Parameterisation and Decadal‐Scale Erosion Assessment

ABSTRACT Ensuring the long‐term erosional stability of post‐mining landforms remains a major challenge in open‐pit mining. Reconstructed landscapes must support the agreed post‐mining land use, such as cattle grazing in the Hunter region of southeastern Australia, requiring stable pasture and minimal soil loss. Numerical modelling is widely used to evaluate landform stability, but continued development and validation of landform evolution models (LEMs) across diverse environments is essential. This study compares the performance of the state‐of‐the‐art soilscape and landform evolution model, SSSPAM, with the first‐generation LEM, SIBERIA, in estimating soil erosion rates and gully development on a constructed post‐mining landform from a coal mine nearing closure in the Hunter region of New South Wales, Australia. Simulations were run over 100 years using a high‐resolution airborne LiDAR‐derived digital elevation model as the initial surface. Both models reproduced gully initiation and upslope migration, with substantially greater gully density under bare‐soil than vegetated scenarios. SIBERIA and SSSPAM produced broadly similar gully patterns without vegetation, while SSSPAM predicted slightly greater gully development when vegetation was present. Estimated erosion rates were comparable between the models: 1.2 and 12.0 t/ha/year (SIBERIA) and 0.9 and 17.9 t/ha/year (SSSPAM) for vegetated and non‐vegetated conditions, respectively. Overall, the results demonstrate the robustness of both models and emphasise the important role of vegetation in mitigating erosion, providing valuable insights for the design and management of sustainable post‐mining landscapes.