Open Cut » Environment
This report covers the achievements of two successive ACARP projects, C1629 (1992-1994), and C4011 (1995-1997), entitled 'Postmining Landscape Parameters for Erosion and Water Quality Control' (PLPEWC). In addition, this report will also cover ACARP project C5009 which is an extension of Field Plot monitoring in this project. The project is a result of close consultations with the mining industry over a considerable time prior to the commencement of the project in 1992. The project combined the skills and expertise of researchers from the School of Land and Food & the Centre for Mined Land Rehabilitation of the University of Queensland, the Queensland Department of Natural Resources, the University of Newcastle and the Australian Coal Industry Research Laboratories in Ipswich, with the skills and experience of environmental officers from 15 open cut coal mines in the Bowen Basin. Close collaboration and consultation between the project partners was maintained throughout the project through a steering committee comprised of representatives from each of the contributing mining companies and research staff.
The project addressed a major problem of the open-cut coal mining industry, viz. 'how to achieve economic postmining reconstruction which meets the criteria of acceptable erosion and runoff water quality'. The project was jointly funded by the Australian Coal Association Research Program (ACARP) and the 6 major coal mining companies, BHP Coal Pty Ltd, MIM Holdings Ltd, Pacific Coal Pty Ltd, Curragh Queensland Mining Ltd, Callide Coalfields Pty Ltd, and Capricorn Coal Management Pty Ltd.
Objectives of the project :
The major objectives of the PLPEWC project were:
(i) to develop appropriate methodologies to determine the critical range of degree of slope - length of slope - vegetative cover combinations for acceptable control of erosion and salt generation, as an aid towards the design of stable and sustainable postmining landforms;
(ii) to survey and determine the success of existing rehabilitation/revegetation strategies as an aid towards the validation of the above mentioned design criteria;
(iii) to provide training and technology transfer to allow the integration of research outcomes into the development of efficient environmental management practices on minesites.
The first two objectives were pursued through a series of experimental programs at 4 different scales: the laboratory flume, the field rainfall simulation plots, the field erosion plots and the field catchments. An erosion survey of existing rehabilitated sites was initiated during the latter part of the project, while a substantial effort was devoted into the integration of the results into computer models that are useful in the landscape design process at the mine. These models are supplied on a CD rom with the main report.
Overall the project has achieved its major objective of providing the industry with methodologies and design packages that will be useful for the prediction, prevention or minimisation of erosion from postmining landscapes. Optimal landscape design can now be achieved using data derived from field plots, field catchments and field rainfall simulator plots. It can also be achieved using laboratory flume data and data derived from routine soil analysis, but is currently limited to bare, unconsolidated materials only. Similarly, salt generation can be predicted from data derived from the laboratory for bare, unconsolidated materials only.
The major outcomes from this project are:
1. An extensive database of physical and chemical properties for 34 materials from the Bowen Basin covering spoil and topsoil;
2. A user-friendly Windows - based PGM (PERFECT/GRASP/MUSLE) design package to determine the optimal combination of slope, slope length and vegetative cover that will limit erosion to acceptable levels;
3. A Windows-based EAMS (Environmental Assessment Management System) package that predicts future landscapes subjected to erosion under a selected set of climatic conditions;
4. A user friendly Windows-based MINErosion model to predict the potential soil loss from laboratory rainfall simulator-tilting flume derived parameters;
5. A SaltRO model to predict potential salt generation from eroding surfaces; and
6. A simple survey methodology to determine the extend of erosion on rehabilitated minesites.
The database of soil/spoil properties and the models are included as a CD-Rom with the main report.