Functions of Designed Cover systems in Semi-Arid Environments of Australia

Baumgartl, Thomas and Mulligan, David R. (2009). Functions of Designed Cover systems in Semi-Arid Environments of Australia. In: Jacques Wiertz and Chris Moran, Enviromine2009 : Proceedings of the First International Seminar on Environmental Issues in the Mining Industry. First International Seminar on Environmental Issues in the Mining Industry, Santiago, Chile, (68-68). 30 September - 2 October 2009.

Author Baumgartl, Thomas
Mulligan, David R.
Title of paper Functions of Designed Cover systems in Semi-Arid Environments of Australia
Conference name First International Seminar on Environmental Issues in the Mining Industry
Conference location Santiago, Chile
Conference dates 30 September - 2 October 2009
Convener Gecamin & SMI
Proceedings title Enviromine2009 : Proceedings of the First International Seminar on Environmental Issues in the Mining Industry
Place of Publication Santiago, Chile
Publisher Gecamin
Publication Year 2009
Sub-type Published abstract
Open Access Status
ISBN 9789568504236
Editor Jacques Wiertz
Chris Moran
Start page 68
End page 68
Total pages 1
Collection year 2010
Language eng
Abstract/Summary Waste material originating from mining and mineral processing inherit properties which can have negative impacts on the environment. Water is, in most cases, a major contributing factor to many of the problems associated with waste material through its role in chemical reactions and as the transport vector of contaminants or suspended load. The avoidance of such problems requires the control of water flow and hence the minimisation of the risk of water coming into contact with contaminated, or potentially contaminating, material. Various strategies are possible to limit the effect of water and water flow as a cause for problems, and they commonly involve the design of a cover system. Such a cover system has to fulfil various functions, which may be in contrast to each other. In a semi-arid environment, covers are primarily designed to minimise water flow into waste material. In order to achieve this objective, such covers may contain a layer with very low permeability values. Under climatic conditions where rainfall may be quite rare but of high intensity when they do occur, the functionality of such a cover is threatened by runoff during rainfall intensities, which exceed the infiltration capacity of the cover. A precipitation buffer layer on top of a low permeability layer is used to compensate for such events and is meant to capture most of the rainfall. Such a system is also known as a store-and-release cover as it is not only designed to capture water during high volume and intense rainfall events, but also to provide sufficient moisture for plant growth during times of no rain. Vegetation is simultaneously used to reduce the volume of water captured from the buffer layer over time. The success of designed covers is based on the parameters set to fulfil the purpose of the cover under the given climatic conditions while at the same time providing for the water needs of a vegetation community. The success of cover systems is also highly dependent on the degree of quality assurance adopted during the actual construction of the cover. This paper will examine the performance of constructed covers by comparing field-measured hydraulic parameters such as hydraulic conductivity and water flow through covers during rain events, with the laboratory-measured parameters initially used for the design of the covers. In the field, there is a high degree of heterogeneity on a spatial scale in parameters like infiltration rate, for example, and this needs to be recognised when making the connections and extrapolations between laboratory tests and field realities.
Subjects E1
9605 Ecosystem Assessment and Management
9609 Land and Water Management
9612 Rehabilitation of Degraded Environments
9614 Soils
050207 Environmental Rehabilitation (excl. Bioremediation)
050206 Environmental Monitoring
079901 Agricultural Hydrology (Drainage, Flooding, Irrigation, Quality, etc.)
Q-Index Code EX
Q-Index Status Provisional Code

 
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Created: Fri, 26 Mar 2010, 16:26:12 EST by Laurelle Elliott on behalf of Centre For Mined Land Rehabilitation