Open Cut » Environment
Most mine sites within Australia have specific rehabilitation objectives in order to return the landscape to an acceptable state after the mine operations cease. In addition to these formal objectives set out by regulators, community expectations for satisfactory rehabilitation are very high, and a company's reputation can diminish if these are not met.
An effective assessment of rehabilitation compliance to the regulator presents significant challenges as the outcome depends on many interacting parts. For example, the influence of climate may distort the efforts of mine sites by masking the true progress that has been achieved. On one hand, mediocre rehabilitation efforts by a mine may be masked by favourable climatic conditions such as ideal rainfall and temperature patterns. On the other hand, superb rehabilitation efforts by a mine may be limited by drought conditions over multiple years just before relinquishment. Consequently, the true efforts put in by a mine and their operators are currently hard to quantify.
Another challenge is to perform a truly evidence based assessment of rehabilitation. As scientific instruments at a point in time cannot capture the whole extent of rehabilitation, a mixture of different surveys and assessments is required in order to provide mine sites with a comprehensive set of evidence for their rehabilitation efforts. The long timeframes involved in rehabilitation further amplify this issue, as some assessment parameters from one month to another are unlikely to change and may only be quantifiable over many years.
In order to address these issues, this project investigated techniques for tracking and predicting open cut mine rehabilitation success and compliance with set out rehabilitation objectives using ecosystem condition assessments and a microclimate monitoring approach coupled with forest growth modelling. The modelling is based on highly accurate microclimatic and ecological data as well as biodiversity habitat attributes specific to a mine area. This comprehensive data further provides regulators and mine managers with evidence for lease relinquishments and offers insights into operational measures that may assist a more effective rehabilitation and therefore lead to relinquishment based on the set out objectives.