School of Geography - Theses
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ItemEnvironmental floods for Victorian regulated rivers( 2005)Dams, whilst critical to society for water supply, impact on the environment and alter flooding patterns downstream of a dam. Floods perform an important role in sustaining many abiotic and biotic components of an ecosystem, such as channel maintenance and triggers for fish spawning. Environmental floods are a promising management technique but their release has only been reported from 16 of more than 45,000 large dams worldwide. This thesis is the first review of issues surrounding the implementation of environmental floods from large Victorian dams. The study identifies the large dams in Victoria that (a) have the most altered flood hydrology downstream of the dam, and (b) have the least physical constraints on releasing floods. The extent of flood regime change from 21 dams is quantified using flood statistics. All of the 21 dams reduced the magnitude of natural 1 to 10-year recurrence interval floods and extended the recurrence interval of natural floods. A worldwide review of environmental floods reveals six major limitations to environmental floods and five factors common to all successful environmental flood releases. One of these limitations - capacity of the dam to release an environmental flood is examined in more detail. Twelve Victorian dams have the physical capacity to release a natural one-year recurrence interval flood. Foremost among these are Thomson, Rocklands, Eildon and Upper Yarra dams which have a high impact on floods and potential to release a flood without requiring infrastructure modifications. Implementing an environmental flood in Victoria is a long term process taking up to ten years. Environmental flood design requires that a link between flood change and ecological condition be established. This requires substantial data to be available. Coordination among stakeholders involved in environmental flood planning, particularly optimising the operation of a dam to maximise environmental benefits of a flood release while minimising impacts on other water users, is a key aspect of environmental flood implementation.
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ItemThe use of life cycle assessment in environmental impact assessment( 2003)The increasing use of Life Cycle Assessment (LCA) in environmental management reflects a shift by some practitioners away from project-level to system-level whole-oflife assessment. However, despite growing support for the adoption of this approach to understanding the impacts on the environment of decisions made within the economy, some researchers have questioned the validity o f the results obtained from it. Moreover, the pressure to cut comers and generate conclusions of value to the client has meant that many LCA studies have been criticized for making claims that cannot be justified by the results. Indeed, when these concerns are contrasted with the success to date of projectlevel EIA methods, it comes as no surprise that some people doubt whether LCA has a future as an environmental impact assessment method. Therefore, the aim of this thesis is to determine whether LCA can be a useful tool in environmental impact assessment. To achieve this aim I begin by classifying problems linked to the release of waste into the environment into two groups, acute and cumulative. I then use this framework to compare the advantages and disadvantages of a range of environmental impact assessment methods, including LCA. During my critique of LCA, I focus on the problem o f uncertainty, and discuss the implications for impact assessment of a lack of site-specific information in the inventory. This analysis leads to a research program that examines the use of LCA in environmental impact assessment. The program comprises: (1) an investigation into how practitioners report the problem of uncertainty in their studies; (2) a case study that examines one way of improving the reliability of LCA results; and (3) a case study that explores the relevance of LCA results for policy development. The conclusions drawn from this thesis are that LCA is not suitable for identifying single-concentrated sources of pollutants and quantifying the direct impacts of particular economic activities. Such an analysis should be left to project-level EIA methods. However, it is possible for LCA to generate useful insight into the management of large-scale environmental effects provided that practitioners collect the spatial and temporal data needed to reliably assess them. If this is done, then LCA is a powerful tool for the development of policy strategies for the management o f cumulative environmental problems.