Application of Markov chain analysis to reclaimed mining landform portfolio management

Authors: Mooder, B Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2615_148

Cite As:
Mooder, B 2026, 'Application of Markov chain analysis to reclaimed mining landform portfolio management', in AB Fourie, G Boggs, J Heyes & M Tibbett (eds), Mine Closure 2026: Proceedings of the 19th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 1-13, https://doi.org/10.36487/ACG_repo/2615_148



Abstract:
The mining industry and regulatory body preference for ‘walk away’ closure remains an obstacle to relinquishment. Mine operators may choose to maintain dormant mine sites in care and maintenance to defer the prohibitive costs of constructing ‘zero maintenance’, long-life reclaimed landforms. Alternately, simpler reclamation designs coupled with post-relinquishment monitoring and maintenance may reduce closure costs while providing long-term reliability and societal value. This work applies stochastic Markov chain analysis to assess projected performance for a hypothetical portfolio of mining landforms by defining asset condition and deterioration. Focusing on covered, vegetated tailings landforms we utilise 5 condition states: (A) exceeding performance targets; (B) performing adequately (good vegetation, some rilling); (C) performing poorly (struggling vegetation, some gullies); (D) imminent failure (poor or patchy vegetation, major gullies, minor tailings exposure); and (F) failed (major tailings exposure or loss of containment). Twelve scenarios are evaluated at the portfolio level, combining 3 initial design capital expenditure levels (low, moderate and high) with 4 long-term management strategies (walk away, neglect, repair and routine maintenance). Transition and cost matrices are informed by literature case histories and professional experience to develop a statistical description of the financial consequences of the different management approaches. The analysis demonstrates that post-relinquishment monitoring and maintenance to manage event-driven landform degradation is less expensive than robust walk away design over a 100-year period, even when evaluated on an undiscounted cumulative cost basis. The results imply that a relinquishment policy framework that accommodates monitoring and maintenance through the analysis of residual risk can improve post-operations landform utility. Explicitly allowing these routine interventions can facilitate the transition from care and maintenance to active post-mining land use managed by government or subsequent users.

Keywords: Markov chains, portfolio management, mine relinquishment, net present cost, residual risk, landform evolution, tailings storage facilities, stochastic modelling

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