Using Landscape Evolution Models to assess the longterm

Using Landscape Evolution Models to assess the long-term erosional stability of tailings dams Greg Hancock, Dimuth Prasad Welivitiya, Garry Willgoose Background Tailings are a by product of mining and the processing of minerals. Tailings are generally highly erodible as they have a fine particle size. They can also contain elevated concentrations of unwanted minerals and process chemicals. Consequently, if released to the environment they can be a significant environmental problem. There have been several high profile cases which have highlighted the human and environmental risk of tailings. A common way to manage tailings is to store them in ‘tailings dams’ where they will remain in perpetuity. There has been little investigation of the long-term erosional behaviour of a tailings dams. Computer based Landscape Evolution Models (LEMs) can provide insight into these new geomorphological entities. LEMS provide information on erosion rates, type of erosion and where erosion is likely to occur and can provide guidance on long-term behaviour. Here a LEM is used to assess tailings dam designs using a range of different surface covers and climates. The modelling and methods here provide a template for tailings dam assessment at other sites globally. The methods here will improve tailings dam design and reduce environmental risk. . stand alone tailings dam gully erosion tailings dam at 100 years gully erosion on tailings dam embankment deposition Outcomes • • . LEMs are useful tools with which to assess post-mining landforms Here we assess two hypothetical tailings dams Provide insights into both short and long-term behaviour Provide a risk assessment of different designs, different surface covers, different climate