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Driven principally by government regulation and societal expectations, mining companies around the world are seeking to mitigate the environmental impacts of mining through mined land rehabilitation programs. The ultimate goal of rehabilitation is to establish an acceptable and sustainable post-mining land use. Mining companies worldwide face the challenge of specifying just what a sustainable post-mining land use will be. The problem is that while regulations require mining companies to assess post-mining land use sustainability, the mechanism for doing so and the factors that should be considered are not specified. We propose a risk-based approach to post-mining land use assessment with the aim of reducing the uncertainty of mine closure and the potential cost of repair of land degradation caused by inappropriate post-mining land use. Grazing is a commonly suggested post-mining land use, particularly in Australia where most mining activities occur on land previously used for cattle grazing. Grazing is also seen as a use suited to rehabilitated mined land because of the lower land productivity required compared to cropping. In this paper we develop a conceptual model of the factors influencing the land degradation risk posed by grazing on rehabilitated mined land. This was done through a literature review to identify potentially important risk factors, followed by a survey of graziers surrounding six open cut mines within the Bowen Basin Region of Queensland, Australia. The survey results were used to develop a profile of the risk factors likely to influence the land management behaviour of graziers within the Bowen Basin. The results of the research highlight that there are three main sets of factors that affect grazing risk on rehabilitated mined land. These are site biophysical characteristics that influence land productivity and commercial grazing viability, factors that influence the land management style of a grazier (principally stocking rate decisions), and factors that influence the commitment of a grazier to comply with any caveats placed on the management of the land. The profile of risk factors obtained for Bowen Basin graziers showed that grazing is likely to be a low risk post-mining land use where land productivity is high enough to support commercial cattle grazing and where land is managed by local graziers. Both the conceptual model and the profile of risk factors described in this paper are precursors to the development of a predictive risk assessment model.

This study analysed the potential economic benefits of the adoption of the technologies that have been developed under a recently funded project. These technologies are the application of an immune response promoter as a pre-harvest spray, and the postharvest dipping of fruit in hot water. The analysis employed in this study could be applied in similar situations where holistic assessments at the grower, supply chain and industry levels are desired. In preliminary trials of the project technologies, it was found that there was a 12% improvement in marketable fruit through the application of the immune response promoter. The hot water treatment was also efficacious in extending the post-harvest performance of fruit. The potential benefits of these technologies were analysed from three levels: firm or grower level, supply chain level and industry level. In analysing returns to growers, three levels of benefits were identified: reduction in average growing costs, improvement in marketable fruit and premium prices paid for improved quality. At the supply chain level, financial benefits that could accrue depend on the performance of individual supply chains, the volumes that the chain partners handle, and retailers' pricing strategies. At the industry level, three sources of benefits were highlighted: extra revenue due to increased quantity in marketable fruit, improvement in quality and savings by sending export fruit by sea rather than air freight. Indicative monetary figures were included to facilitate stakeholders in gauging the benefits under their specific situations.

Regulation of mining in Queensland, Australia requires completed rehabilitation to result in the site being safe, stable, presenting no adverse off-site impacts and for a sustainable end use acceptable to stakeholders to be designated. By 2008, an estimated area of 70,000 ha of the coal-mining region of central Queensland had been disturbed by mining activities of which some one third has been rehabilitated. The remaining notional accrued rehabilitation liability exceeds A$1 billion. Rehabilitation of mined land in central Queensland is performed by re-contouring spoil heaps to reduce slope angles, applying a layer of topsoil, and planting various combinations of pasture grasses, shrubs and trees. Approximately half of the rehabilitated areas have been revegetated using bushland species native to the region and half to exotic pasture species suited to cattle grazing. Vegetation cover is valuable in protecting the soil surface from the erosive forces of the often-intense summer rains that occur in the region. Where pasture productivity is high, there is sufficient vegetation both to protect the soil surface and to support grazing. This outcome has been demonstrated both theoretically and in small-scale trials. However, inappropriate grazing management (overgrazing) may reduce the amount of vegetation cover below that needed to protect the soil. The style of land management practised by the manager of the cattle is therefore critical to the sustainability of grazing as an end use. This paper reports on research into the management style likely to be used by the region’s graziers if granted tenure of mined land. Graziers’ management style was modelled as being influenced by their characteristics and circumstances. The chief influences were found to be: • The financial stability of the grazier's business (25%). • The effect of interventions that a company may take; for example, building respectful, trusting relationships with graziers (23%). • Graziers' non-financial motives in seeking tenure of mined land (17%). • Graziers' underlying rural values and attitudes to land management (14%). • The property's operational flexibility (12%). • The external climatic and economic environment (9%). An understanding of factors that influence the grazing management of mined land can be used to assess risks, suggest interventions to reduce grazing risks, to guide the planning of future rehabilitation work, and to support a company's end use proposal to the regulator.