Landloch Pty Ltd
Rob Loch (B.Agr.Sc., B.A., PhD, CPSS) has over 45 years’ experience in the research and application of land management, soil conservation, and land rehabilitation.
Rob is recognised as a Certified Professional Soil Scientist (CPSS), with specialist fields including runoff and erosion control; effects of soil properties on land productivity and stability; land rehabilitation; soil management; sediment properties and soil erodibility, soil erosion and landform evolution modelling, and waste landform design.
He has been at the forefront of minesite landform design in Australia for over 20 years, and is:
Mine sites he has worked with have won awards for rehabilitation success and achieved rapid and successful bond return.
Towards a broader perspective on design of waste landforms
Viewed through a national perspective, there is enormous variation not only in the factors likely to cause erosive failure of a mine waste landform, but also in the factors to be considered to denote “success”.
For arid zones (e.g., 200-250 mm annual rain), the low levels of vegetation cover that can be achieved mean that the properties of the materials placed and the landform design adopted can be critical for long-term stability. Managing material properties can be crucial, as can be the use of rock and tree debris to alter erodibility.
For wetter zones, the impact of vegetation can be much greater, and – for areas of moderate rainfall (~600-800 mm/y) but low rainfall erosivity – designing a stable waste landform can be relatively easy and the range of design options quite large. It is not surprising that interest in designing “natural” landforms is greatest in this zone, though features of natural landforms have long been used in the arid zone.
For areas where either (or both) rainfall erosivity and waste material erodibility are much higher, the challenges of achieving stability increase, the need for understanding material properties is much greater, and the range of design options is narrowed.
As well, there are always “special cases” that present design challenges. This may be due to the need to produce an unusual landform that meets site imperatives for reduced footprint or other specific design requirements, possibly to deal with an unusual waste, or area of extreme sensitivity.
This paper will, firstly provide some of the above perspective, and then move to considering, the wide range of design tools that are available for producing waste landform designs, including:
One of those tools is the consideration of natural landforms, but, when used as the major focus of design, it can be restrictive and has potential to deliver sub-optimal outcomes.
The paper will also outline an alternative landform design approach using application of “landform design rules” developed using erosion modelling to guide design of natural landforms that are both stable and are consistent with the properties of the materials used in their construction.
Stream 1 - Pathways to relinquishment and opportunities to transition to productive alternate land usesUnderstanding Acid Mine Drainage / Acid Rock Drainage and the implications for rehabilitation and closureHarnessing Hyperaccumulator Plants to Phytoremediate Contaminated Mining SitesIssues in Tropical Forest Rehabilitation Post Mining
Presented on 20th June 2019 at the 9th Annual Best Practice Ecological Rehabilitation of Mined Lands Conference (2019)