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.
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ItemMunicipal water use for irrigation in Victoria, Australia( 1998)Recent water industry reforms, pressure for ecologically sustainable development (ESD) and administrative changes to local government such as the introduction of compulsory competitive tendering (CCT) have the potential to affect municipal water use in Victoria. This thesis examines how local governments in Victoria manage water used for irrigation of council green areas. Global and Australian water issues, local government in Australia, ESD and local government water management, and Victoria's water industry and pricing system are discussed. Forty five councils in Victoria completed the survey `Municipal Water Use for Irrigation'. Results indicate that water use is becoming increasingly important to local government and the perceived need for water conservation is driven by both economic and environmental factors. Pressure for ESD is having an impact on municipal water use, particularly as many councils develop environmental management strategies or similar policies. Recent State Government reforms to the water industry, including changes to water pricing and charges for water use, are likely to have an affect on future consumption levels. Changes to the operational structure of local government in recent times, particularly the introduction of CCT, are also having an impact on water management. Councils reponses to CCT were mixed; some saying it created opportunities for improved water management, while others felt it gave them less control over water use. However, CCT has probably not been in operation long enough for its effect to be fully gauged. Councils are beginning to implement strategies for water conservation, including the application of xeriscape principles to council landscapes and improved horticultural practices and irrigation management. Further work is required at a local government level before significant reductions in water use can occur. This includes an audit of council water use, the development of water management strategies, improved landscape management practices and community education.
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ItemAn impact analysis of enhanced-greenhouse climate change on the Australian alpine snowpack( 1997)This Thesis is concerned with the sensitivity response of the Australian alpine snowpack to the onset of possible enhanced-greenhouse climatic conditions in the 21st Century. The analysis procedure involved the use of both physical and empirical simulation models, and the various caveats associated with each of these components should be assessed when interpreting the results. A statistical downscaling model was constructed, which converted large-scale synoptic data into daily changes in the alpine snowpack. This snow model was calibrated for the Falls Creek site in the Victorian Alps (elevation 1649 m). The model was able to reproduce observed fluctuations in the observed snowpack when it was driven by largescale atmospheric temperature, humidity and airstream inputs. The research methodology used an extensive archive of daily output from the CSIRO 9- level General Circulation Model (GCM). This model incorporated a Mixed Layer Ocean, and operated at an R21 horizontal resolution. A daily-scale validation of a 24- year 1xCO2 control climatology revealed the existence of a number of biases within the simulated atmospheric fields. The most serious of these was a negative bias in tropospheric temperatures of between 2 C and 5 C. These biases were adjusted, and the GCM was used to drive the statistical snow model. The resulting simulation was successfully validated against observed data. The climate change sensitivity evaluation was conducted by applying a 29-year doubled-CO2 data-set from the CSIRO 9-level GCM to the statistical snow model. The resulting simulation showed an extremely high sensitivity response from the model site, with values such as mean snow cover duration and peak seasonal snow depth decreasing by over 90%. This was largely attributed to a particularly strong warming in the driving GCM of around 4.8 C. A range of further sensitivity perturbations were conducted by varying the input temperature fields (in both the GCM and observed atmospheric data-sets) by one degree Celsius increments. The mean snow model response suggested a quasi-exponential decay relationship, with the first degree of warming producing the strongest reduction in snow duration and snowpack depth. For example, mean maximum snow depths decreased by around 40% when the observed atmosphere was increased by 1 C. These changes were caused by a simultaneous decrease in snowfall and a very strong increase in ablation. Some preliminary impact analysis was conducted on various snow-affected sectors. Within the biophysical context, the snowmelt runoff into the Dartmouth Reservoir of northeast Victoria was calculated using a relatively simple terrain interpolation/snowmelt scheme. The seasonal runoff pattern was then perturbed to simulate an environment in which no alpine snowpack existed. The resulting runoff pattern contained an abnormally high mean winter maxima and a depressed spring inflow volume. A socioeconomic analysis was also conducted into the viability of the Australian winter tourism industry under a range of scenario conditions. A statistical regression relationship was delineated between the duration of the snowpack and visitation numbers at various alpine resorts. The analysis suggested that revenue generation and hence commercial feasibility could be threatened by a moderate reduction in the mean size of the Australian snowpack.
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ItemA comparative analysis of litter generated at shopping centres, roadsides and riverside-foothpaths within the Plenty River catchment and the extent to which litter from these sources is reflected in the composition of bank litter along the Plenty River( 1996)Litter studies often face the problem of category overlaps when attempts are made to classify litter items. This study proposes a classification that is aimed at minimising the problem of category overlaps. It then employs this classification in comparing litter characteristics at various generation points within the Plenty River catchment and the extent to which the litter found entangled on banks of the river relates to that at the various source sites. In addition, the local litter policies and management strategies are reviewed against experiences from other parts of the world. The litter classification employed in this study describes litter items on the basis of their use-origin and material-type. Litter generation areas at which survey was undertaken were Greensborough, Montmorency and Lower Plenty shopping centres; roadsides adjacent to bridge sites and riverside footpaths along the Plenty River. Riverbank litter sampling was undertaken at points near roadside and riversidefootpath survey sites. A comparative review of litter policies and management strategies from various parts of the world revealed some desirable aspects that could benefit litter management in Australia. The `Systems Approach' as the guide to litter policy and management strategy formulation in Victoria was found to have inherent weaknesses that partly account for the persistence of litter pollution. Using data from litter survey at shopping centres, roadsides and riverside footpaths, it was found that: (a) Litter generated within different shopping centres was not significantly different but smoking-related litter pose the most serious cause of concern owing to its dominant frequency, (b) litter at roadsides next to bridge-sites within the catchment had significant differences leading to a conclusion that roadside litter is mostly a function of factors specific to a site. At the same time, a higher relative incidence of litter was observed at roadside points nearer bridges than further up the road; (c) significant differences exist in material-type frequency composition of litter between riverside footpath sites and this was viewed as indicative of a higher likelihood among individuals to improperly dispose of certain litter items than others. On the basis of data from riverbank litter survey, this study found that: (a) the distribution of litter by type of material on different types and extent of riverbank vegetation cover is random; (b) riverbank morphology does not to influence the distribution of total litter items entangled on a riverbank; (c) litter generated at riverside footpaths has a higher relative likelihood of polluting the river banks than that generated at more remote locations (shopping centres and roadsides).