To see the other types of publications on this topic, follow the link: Murray-Darling Basin.
Dissertations / Theses on the topic 'Murray-Darling Basin'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 49 dissertations / theses for your research on the topic 'Murray-Darling Basin.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Foster-Thorpe, Frances C. "Accountability interactions : mutliple accountabilities in the Murray-Darling basin plan." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:aac0e39b-f397-4292-baf9-e99c93c98c7d.
Full textAbstract:
This thesis investigates whether different public accountability forums interact with one another when they oversee the same decision maker. It contributes to the larger study of how decision makers are held to account in constitutional democracies where the simultaneous operation of multiple accountability relationships has become routine. Looking beyond the dominant assumption that multiple forums autonomously assess a decision maker's accountability against different and diverging standards, I aim to understand whether forums can influence the standards against which other forums evaluate the same decision maker. I draw on political and normative understandings of public accountability to answer one central question: do different public accountability forums interact with one another in a way that influences the scope of what a decision maker is obliged to account for and the normative standards against which that account is evaluated? Answering this research question involves examining the mechanisms by which interactions might occur and the motivations of actors to interact. I begin by critically reviewing the literature on multiple accountabilities, arguing that existing approaches can only partially explain how public accountability is constructed in multiple accountability regimes. I argue the focus on typologies of accountability emphasise the attributes of individual forums and overlook the broader dynamics of the accountability regime. I then develop an analytical framework to examine how the interactions between different forums, and other actors, might reshape the accountability dialogue. This framework is used to analyse the case of the Murray-Darling Basin Plan in Australia (2008-2012). By presenting a contextSrich analysis of interactions between forums, and other actors, I find that multiple forums act in concert with one another and other actors to contest and then reshape the standards against which the two decision makers are evaluated. The thesis concludes by discussing the implications of recognising accountability interactions for understanding multiple accountability regimes.
2
Dwyer, Brian James, University of Western Sydney, College of Social and Health Sciences, and School of Natural Sciences. "Aspects of governance and public participation in remediation of the Murray-Darling Basin." THESIS_CSHS_NS_Dwyer_B.xml, 2004. http://handle.uws.edu.au:8081/1959.7/776.
Full textAbstract:
This thesis addresses the question “What is the essence of the Murray Darling river system conundrum that is usually posed as an issue of environmental remediation?”- following perceptions of problems in catchment strategy formulation regarding project selection and public consultation. The question is initially seen as having four facets – governance, public, participation and remediation. An initial literature review indicated that previous examination of these topics seemed insufficiently radical or comprehensive for the enquiry’s purposes, seeming not to attribute full humanness to members of the public. A fieldwork program of quasi-anthropological nature was conducted. Interpretation of the fieldwork reports focuses primarily on the lack of attribution of full humanness to members of the public. Interpretive techniques including a phenomenological-style process was applied and found that the district houses a number of unrecognised people “nexors’ occupying linking or nexus roles who exercise personal skills and initiatives to underpin effective remediation outcomes. Towards the end of the fieldwork program, further literature indicated that the initial four-facet nature of the enquiry should be reformulated, to include the overall nature of western society as it appears in the district (in place of participation), to reconstitute the concept of remediation more radically. Governance as a topic is broader than the ways in which it appears in the examined district, and suitable hybridizing of competing world view concepts remains unresolved in this thesis<br>Doctor of Philosophy (PhD)
3
Baumgartner, Lee Jason, and n/a. "Effects of weirs on fish movements in the Murray-Darling Basin." University of Canberra. Resource, Environmental & Heritage Sciences, 2005. http://erl.canberra.edu.au./public/adt-AUC20051129.142046.
Full textAbstract:
Dams and weirs are widely implicated in large-scale declines in both the range and abundance of aquatic fauna. Although many factors are involved, such declines are commonly attributed to the prevention or reduction of migration, reductions in available habitat, alteration of natural flow regimes and changes to physicochemical characteristics. In Australia, studies into the ecological effects of these impacts are limited, and have concentrated mainly on species of recreational and commercial importance. Subsequently, the adverse effects of dams and weirs, and suitable methods of mitigation, remain largely unknown for many other taxa. Therefore, the major aim of this thesis is to investigate the ecological effects of dam and weir construction on previously unstudied migratory assemblages of fish and macroinvertebrates in the Murray-Darling Basin. It is anticipated that the results of these studies will feed back into improved management strategies that help arrest the previously observed declines of aquatic fauna. Initially, fish communities were sampled, by boat electrofishing, from both reference sites and downstream of Balranald and Redbank weirs on the lower reaches of the Murrumbidgee River, Australia. Sampling was stratified over large spatial and temporal scales to gain a comprehensive understanding of species most affected by the presence of these two barriers. In general, the weirs obstructed fish migrations during summer and autumn and many species of small-bodied fish such as Australian smelt, western carp gudgeon, fly-specked hardyhead and crimson-spotted rainbowfish accumulated downstream of Balranald Weir. In addition, downstream accumulations of juveniles of larger-bodied species such as bony herring, common carp and goldfish were also detected. Although many previous studies had either documented or hypothesised that upstream migrating fish accumulate downstream of migration barriers, none attempted to quantify the size of such populations. Therefore, a simple but efficient method to estimate the size of migratory populations was assessed at the Balranald Weir site. The application of two commonly used estimation techniques yielded relatively reliable results for seven species that accumulated downstream of the weir. Population size estimates were greatest for most species during summer and autumn, where accumulations as high as 800 fish per day were detected. The largest calculated population size estimates, in addition to the
greatest temporal variation, of any individual species was observed in bony herring. Given the simplicity of the technique and the relative accuracy of population estimates, it was concluded that these methods could easily be applied to other weirs where the size of migratory populations is of particular interest. A study investigating the effects of Yanco Weir on the diets of three migratory percichthyid species, Murray cod, trout cod and golden perch was also conducted. Observed spatial variation in a number of trophic processes strongly implicated Yanco Weir as a major contributor to increased competition among percichthyid species on the Murrumbidgee River. The greater relative abundance of percichthyids from downstream samples, combined with increases in dietary overlap and a greater percentage of empty stomachs, also suggested percichthyids may be significantly affecting the relative abundance of potential prey items such as freshwater prawns and Australian smelt. These significant changes in dietary composition were likely related to migratory behaviour, as these species accumulated downstream of the weir, and could be readily expected at other sites where passage is obstructed. It was suggested that the construction of suitable fish passage facilities would effectively reduce the probability of migratory fish accumulating and, subsequently, potential effects of dams and weirs on trophic processes. Since it was established that dams and weirs of the Murrumbidgee River were significantly affecting migratory fish communities, an innovative but relatively inexpensive fishway design, the Deelder fish lock (after Deelder, 1958), was constructed and assessed for wider application throughout the Murray-Darling Basin. The Deelder lock was effective at mitigating the effects of Balranald Weir by providing passage for a wide range of size classes and species of fish; but importantly, the structure enabled the passage of most species previously observed to accumulate downstream of the structure. Most significant was the ability of the fish lock to pass substantial numbers of small-bodied fish, which were previously not considered migratory, suggesting that these species should be considered when developing options to mitigate the effects of other dams and weirs throughout the Murray-Darling Basin. A significant finding of this study was the realisation that substantially more species and size classes of Australian native fish are migratory than previously thought.
Subsequently, it is recommended that, when designing facilities to mitigate the effects of a dam or weir, the structure of the entire migratory community is considered when developing operating parameters. Various options for mitigating the effects of dams and weirs are discussed, but it was concluded that the construction of effective fishways would be the most appropriate means of restoring migration pathways to Australian native fish. A strategic approach for assessing and adaptively mitigating the effects of dams and weirs is presented and discussed.
4
King, Alison Jane 1974. "Recruitment ecology of fish in floodplain rivers of the southern Murray-Darling Basin, Australia." Monash University, Dept. of Biological Sciences, 2002. http://arrow.monash.edu.au/hdl/1959.1/8391.
Full text
5
Baggiano, Olivier. "The Murray - Darling Turtles: Gene Flow and Population Persistance in Dryland Rivers." Thesis, Griffith University, 2012. http://hdl.handle.net/10072/367471.
Full textAbstract:
Australia’s largest and most important waterway- the Murray-Darling Basin (MDB) - is under threat owing to predicted increases in temperature extremes and reduction in rainfall - runoff in the coming decades. Management strategies are required that incorporate an understanding of dispersal patterns of the MDB fauna and flora. Patterns of dispersal have typically been studied through direct organismal studies but genetic approaches, in which the movement of genes in the landscape is used as a correlate of species dispersal, can provide a more comprehensive view by investigating at a much larger temporal and spatial scale. Genetic connectivity (dispersal) is influenced by the biology of the species, and by flow regime and the dendritic pattern of the network in riverine landscapes. An understanding of the relative influence of each on connectivity is required to deliver informed management
strategies. Decisions regarding whether management for conservation is necessary also require an understanding of a species susceptibility to a changing environment. Species already exhibiting deleterious trajectories under current flow regimes in the basin may require more drastic measures than those that have remained unaffected.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>Griffith School of Environment<br>Science, Environment, Engineering and Technology<br>Full Text
6
Dwyer, Brian James. "Aspects of governance and public participation in remediation of the Murray-Darling Basin /." View thesis, 2004. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20060517.130206/index.html.
Full textAbstract:
Thesis (Ph.D.) -- University of Western Sydney, 2004.<br>"A thesis submitted for the degree of Doctor of Philosophy of the University of Western Sydney, Sydney, January 2004." Includes bibliography : leaves 359 - 369.
7
Perry, Nicola. "Bounded Properties, Interconnected Ecosystems: Watering Private Wetlands in the Murray Darling Basin, Australia." Thesis, The University of Sydney, 2022. https://hdl.handle.net/2123/28618.
Full textAbstract:
The Murray Darling Basin (MDB) is Australia’s largest river and wetlands network and has enormous environmental, economic and cultural importance. The over 30,000 wetlands of the MDB floodplains are an essential element of this vast and complex river ecosystem. However, the water dependent ecosystems of the MDB have been modified, largely to service irrigation and consumptive human needs. Ensuring wetlands receive water is essential to the survival of the MDB, and the process of managing this water is investigated herein. MDB water management reform has reintroduced environmental flows to support the seasonal water needs of floodplains, ephemeral creeks and wetlands. However, the vast majority of MDB wetlands are located on private property which has been identified as a key barrier to effective water delivery. Water for wetlands is now delivered directly to wetlands located on private property through different initiatives which involve Government, Not for Profit and private actors.
8
Boys, Craig Ashley, and n/a. "Fish-Habitat Associations in a Large Dryland River of the Murray-Darling Basin, Australia." University of Canberra. Resource, Environmental & Heritage Sciences, 2007. http://erl.canberra.edu.au./public/adt-AUC20070807.112943.
Full textAbstract:
Many aspects concerning the association of riverine fish with in-channel habitat remain
poorly understood, greatly hindering the ability of researchers and managers to address
declines in fish assemblages. Recent insights gained from landscape ecology suggest
that small, uni-scalar approaches are unlikely to effectively determine those factors that
influence riverine structure and function and mediate fish-habitat associations. There
appears to be merit in using multiple-scale designs built upon a geomorphologically-derived
hierarchy to bridge small, intermediate and large spatial scales in large rivers.
This thesis employs a hierarchical design encompassing functional process zones
(referred to hereafter as zones), reaches and mesohabitats to investigate fish-habitat
associations as well as explore patterns of in-channel habitat structure in one of
Australia's largest dryland river systems; the Barwon-Darling River.
In this thesis, empirical evidence is presented showing that large dryland rivers are
inherently complex in structure and different facets of existing conceptual models of
landscape ecology must be refined when applied to these systems. In-channel habitat
and fish exist within a hierarchical arrangement of spatial scales in the riverscape,
displaying properties of discontinuities, longitudinal patterns and patch mosaics. During
low flows that predominate for the majority of time in the Barwon-Darling River there
is a significant difference in fish assemblage composition among mesohabitats. There is
a strong association between large wood and golden perch, Murray cod and carp, but
only a weak association with bony herring. Golden perch and Murray cod are large
wood specialists, whereas carp are more general in there use of mesohabitats. Bony
herring are strongly associated with smooth and irregular banks but are ubiquitous in
most mesohabitats. Open water (mid-channel and deep pool) mesohabitats are
characterised by relatively low abundances of all species and a particularly weak
association with golden perch, Murray cod and carp. Murray cod are weakly associated
with matted bank, whereas carp and bony herring associate with this mesohabitat patch
in low abundance.
Nocturnal sampling provided useful information on size-related use of habitat that was
not evident from day sampling. Both bony herring and carp exhibited a variety of
habitat use patterns throughout the die1 period and throughout their lifetime, with
temporal partitioning of habitat use by juvenile bony herring and carp evident. Much of
the strong association between bony herring and smooth and irregular banks was due to
the abundance of juveniles (<100mm in length) in these mesohabitats. Adult bony
herring (>100mm length) occupied large wood more than smooth and irregular banks.
At night, juvenile bony herring were not captured, suggesting the use of deeper water
habitats. Adult bony herring were captured at night and occupjed large wood, smooth
bank and irregular bank. Juvenile carp (<200mm length) were more abundant at night
and aggregated in smooth and irregular banks more than any other mesohabitat patch.
Adult carp (>200mm length) occupied large wood during both day and night.
There is a downstream pattern of change in the fish assemblage among river zones, with
reaches in Zone 2 containing a larger proportion of introduced species (carp and
goldfish) because of a significantly lower abundance of native species (bony herring,
golden perch and Murray cod) than all other zones. In comparison, the fish assemblage
of Zone 3 was characterised by a comparatively higher abundance of the native species
bony herring, golden perch and Murray cod. A significant proportion of the amongreach
variability in fish assemblage composition was explained at the zone scale,
suggesting that geomorphological influences may impose some degree of top-down
constraint over fish assemblage distribution. Although mesohabitat composition among
reaches in the Barwon-Darling River also changed throughout the study area, this
pattern explained very little of the large-scale distribution of the fish assemblage, with
most of the variability in assemblage distribution remaining unexplained. Therefore,
although mesohabitat patches strongly influence the distribution of species within
reaches, they explain very little of assemblage composition at intermediate zone and
larger river scales. These findings suggest that small scale mesohabitat rehabilitation
projects within reaches are unlikely to produce measurable benefits for the fish
assemblage over intermediate and large spatial scales in the Barwon-Darling River. This
indicates the importance taking a holistic approach to river rehabilitation that correctly
identifies and targets limiting processes at the correct scales.
The variable nature of flow-pulse dynamics in the Barwon-Darling River creates a
shifting habitat mosaic that serves to maintain an ever-changing arrangement of habitat
patches. The inundation dynamics of large wood habitat described in this thesis
highlights the fragmented nature of mesohabitat patches, with the largest proportion of
total in-channel large wood remaining unavailable to fish for the majority of the time.
At low flows there is a mosaic of large wood habitat and with increasing discharge more
potential large wood habitat becomes available and does so in a complex spatial
manner. What results in this dryland river is a dynamic pattern of spatio-temporal
patchiness in large wood habitat availability that is seen both longitudinally among
different river zones and vertically among different heights in the river channel. Water
resource development impacts on this shifting habitat mosaic.
Projects undertaking both fish habitat assessment and rehabilitation need to carefully
consider spatial scale since the drivers of fish assemblage structure can occur at scales
well beyond that of the reach. Fish-habitat associations occurring at small spatial scales
can become decoupled by process occurring across large spatial scales, making
responses in the fish assemblage hard to predict. As rivers become increasingly
channelised, there is an urgent need to apply research such as that conducted in this
thesis to better understand the role that in-channel habitats play in supporting fish and
other ecosystem processes. Habitat rehabilitation projects need to be refined to consider
the appropriate scales at which fish assemblages associate with habitat. Failure to do so
risks wasting resources and forgoes valuable opportunities for addressing declines in
native fish populations. Adopting multi-scalar approaches to understanding ecological
processes in aquatic ecosystems, as developed in this thesis, should be a priority of
research and management. To do so will enable more effective determination of those
factors that influence riverine structure and function at the approariate scale.
9
Burdack, Doreen. "Water management policies and their impact on irrigated crop production in the Murray-Darling Basin, Australia." Phd thesis, Universität Potsdam, 2014. http://opus.kobv.de/ubp/volltexte/2014/7224/.
Full textAbstract:
The economic impact analysis contained in this book shows how irrigation farming is particularly susceptible when applying certain water management policies in the Australian Murray-Darling Basin, one of the world largest river basins and Australia’s most fertile region.
By comparing different pricing and non-pricing water management policies with the help of the Water Integrated Market Model, it is found that the impact of water demand reducing policies is most severe on crops that need to be intensively irrigated and are at the same time less water productive.
A combination of increasingly frequent and severe droughts and the application of policies that decrease agricultural water demand, in the same region, will create a situation in which the highly water dependent crops rice and cotton cannot be cultivated at all.<br>Die ökonomische Folgenanalyse in diesem Buch zeigt, dass insbesondere Landwirte, die stark auf Bewässerung angewiesen sind, von Wasserregulierungsstrategien im Australischen Murray-Darling Becken betroffen sind. Dieses Gebiet ist eines der größten Flussbecken weltweit und zugleich Australiens fruchtbarste Region.
Durch den Vergleich von verschiedenen Preisstrategien und anderen Ansätzen konnte mit Hilfe des Water Integrated Market Models herausgefunden werden, dass die Auswirkungen auf hochgradig wasserabhängige Feldfrüchte mit geringeren Wasserproduktivitäten am stärksten sind.
Die Kombination von häufigeren und intensiveren Trockenzeiten und einer Regulierungspolitik mit dem Ziel, die Nachfrage nach Wasser zu verringern, führt dazu, dass in ein und derselben Region hochgradig wasserabhängige Feldfrüchte wie Reis und Baumwolle mit geringeren Wasserproduktivitäten nicht mehr angebaut werden können.
10
Mall, Neeraj. "A multi-proxy approach to track ecological change in Gunbower Wetlands, Victoria, Australia." Thesis, Federation University Australia, 2021. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/182595.
Full textAbstract:
The wetlands of the Murray-Darling Basin have come under the threat of a drying climate, the over-allocation of water for irrigation agriculture and widespread catchment disturbance. A synthesis of many paleolimnological assessments undertaken in the upper and lower sections of the Murray floodplain, and the Murrumbidgee, reveal considerable ecological change in wetlands from early in European settlement. The wetlands of the Gunbower Forest lie in the middle reaches of the Murray River. They are located on Gunbower Island that is deemed a wetland of international significance under the Ramsar Convention and an icon site under the Living Murray Initiative. Many Gunbower Island wetlands are located in protected forests, while others are within a zone developed for irrigation, mostly dairy, agriculture. This study analysed the sedimentary records of two wetlands within the forest estate and two within irrigation lands intending to compare long term change in the Gunbower wetlands to studies on floodplains both up and downstream, and to assess the relative impact of regional causes of change and that of local land use. Sediments constitute natural archives of past environmental changes. Sediment records were recovered from four wetlands and radiometric dating and multi-proxy paleoecological techniques were applied to assess how these wetlands have responded to changes in human occupation and other factors, such as climate. Then, extracted sediment cores were taken from Black (core length: 84 cm) and Green (86 cm) Swamps located in the forest, and Taylors (94 cm) and Cockatoo (74 cm) Lagoons were situated amongst dairy farms. In order to reconstruct ecological and water quality changes from the study sites, the cores were analysed using four different analysis techniques, i.e., Itrax-XRF (X-Ray Fluorescence) scanning, Lead-210 (210Pb) dating, Stable isotope and diatom analysis. XRF scanning provided evidence of the elemental composition of the cores. Detrital enrichment in the lower parts of all cores was observed, indicating elevated erosion rates or low water levels. In addition to this, some recent metal pollution was evident with high Cu, Ni and Pb inputs. Stable isotopes provided limited information on the carbon and nitrogen sources. The<br>Doctor of Philosophy
11
McArdle, Peter Ian. "Transforming water scarcity conflict: community responses in Yemen and Australia." Thesis, The University of Sydney, 2022. https://hdl.handle.net/2123/29933.
Full textAbstract:
When water is scarce, disputes over how to share it fairly and effectively are frequent. Understanding how people view and respond to water scarcity conflict is essential if it is to be addressed constructively. Through an interdisciplinary lens of hydropolitics and peace and conflict studies, this research used semi-structured interviews and interpretive phenomenological analysis (IPA) to investigate lived experience of sharing scarce water resources in Australia’s Murray-Darling/Barka Basin and Yemen’s Jibal as-Sarawat. Across divergent hydrological, cultural and political contexts, the study gained rich insight into how top decision-makers, mid-level community leaders and grassroots water sharers make sense of their relationships to water and emergent conflict in the face of water scarcity, as well as barriers to and opportunities for fair and peaceful water sharing. The study demonstrated that water scarcity conflict can wear down community resilience long before physiological needs arise, with devastating effects on mental health and social cohesion. Unpredictability, lack of information, social division and perceived injustice among basin stakeholders represent barriers to constructive water sharing outcomes. Opportunities to transform this conflict lie in expanding understandings of hydro-hegemony to incorporate the satisfaction of basic human water needs best understood as social in nature. However, this represents an ongoing process which is costly and replete with paradox. Despite water scarcity theory, policy and practice being dominated by positivist approaches, community resilience to the immense stresses of water scarcity can be found in acknowledging and holding emergent tensions between predictability and adaptability; simplicity and complexity; and personal and social responsibility.
12
Allen, David Andrew. "Electrical conductivity imaging of aquifers connected to watercourses : a thesis focused on the Murray Darling Basin, Australia." University of Technology, Sydney. Faculty of Science, 2007. http://hdl.handle.net/2100/428.
Full textAbstract:
Electrical imaging of groundwater that interacts with surface watercourses provides detail on the extent of intervention needed to accurately manage both resources. It is particularly important where one resource is saline or otherwise polluted, where spatial quantification of the interacting resources is critical to water use planning and where losses from surface waterways need to be minimized in order to transport water long distances. Geo-electric arrays or transient electromagnetic devices can be towed along watercourses to image electrical conductivity (EC) at multiple depths within and beneath those watercourses. It has been found that in such environments, EC is typically related primarily to groundwater salinity and secondarily to clay content. Submerged geo-electric arrays can detect detailed canal-bottom variations if correctly designed. Floating arrays pass obstacles easily and are good for surveying constricted rivers and canals. Transient electromagnetic devices detect saline features clearly but have inferior ability to detect fine changes just below beds of watercourses. All require that water depth be measured by sonar or pressure sensors for successful elimination of effects of the water layer on the data. The meandering paths of rivers and canals, combined with the sheer volume of data typically acquired in waterborne surveys, results in a geo-referencing dilemma that cannot be accommodated using either 2D imaging or 3D voxel imaging. Because of this, software was developed by the author which allows users to view vertical section images wrapped along meandering paths in 3D space so that they resemble ribbons. Geo-electric arrays suitable for simultaneous imaging of both shallow and deep strata need exponentially spread receiver electrodes and elongated transmitter electrodes. In order to design and facilitate such arrays, signed monopole notation for arrays with iv segmented elongated electrodes was developed. The new notation greatly simplified generalized geo-electric array equations and led to processing efficiency. It was used in the development of new array design software and automated inversion software including a new technique for stable inversion of datasets including data with values below noise level. The Allen Exponential Bipole (AXB) array configuration was defined as a collinear arrangement of 2 elongated transmitter electrodes followed by receiver electrodes spaced exponentially from the end of the second transmitter electrode. A method for constructing such geo-electric arrays for use in rivers and canals was developed and the resulting equipment was refined during the creation of an extensive set of EC imaging case studies distributed across canals and rivers of the Australian Murray- Darling Basin. Man made and natural variations in aquifers connected to those canals and rivers have been clearly and precisely identified in more than 1000 kilometres of EC imagery.
13
Black, Richard, and richard black@rmit edu au. "Site Knowledge: in Dynamic Contexts." RMIT University. Architecture and Design, 2009. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20091028.095536.
Full textAbstract:
The PhD is concerned with the construction of site knowledge and how this is transformed into knowing where and how to intervene in a river system close to ecological collapse. It involves three overlapping topics: Site knowledge and its impact upon the design process Development of tools and techniques appropriate for working on a particular type of site condition: the threshold between land and water Transitory: the impact of dynamic processes and events on inhabitation Site knowledge emerges from a process of investigating a location. It is generated by on-site and off-site operations. This involves the architect in a dynamic set of relationships - between encounters on the ground in the here and now, with more remote encounters with the site from the studio and archive. This mode of site study amplifies the impact of scale shift and it exposes the variable and provisional status of a location, while also providing a way of operating in environments that can be considered dynamic. The PhD is premised upon the need for a work to relate to its surrounding environment. The hinged meaning between the terms a site and to site have relevance to the design process. A site, as a noun, suggests a specific place, such as a plot of land, whereas the verb to site, suggests that a work will be placed in relation to other things. Site knowledge is thus generated through the act of describing a place, through the act of making drawings and other descriptions of that place. It generates ways of conceptualising a site and leads to action: knowing how and where to intervene in a location. The River Murray provided a context for the project work of the PhD. Research led to tools for recording (on site) and interpreting (off site) the impacts of flood events on the settlements on the riverbanks that were protected by levees that worked against the natural forces of the system. The research culminated in a range of designs that demonstrated how to integrate town and tourist developments into the re-established cyclical flows necessary for the health of the system.
14
Job, Thomas Anthony. "A systemic investigation of coastal acid sulfate soil acidification in the River Murray Estuary, South Australia." Thesis, University of Sydney, 2020. https://hdl.handle.net/2123/23474.
Full textAbstract:
Extensive coastal acid sulfate soil (CASS) oxidation was observed in the River Murray Estuary (RME), South Australia, during an extreme drought (the Millennium Drought, 1996–2010). CASS oxidation causes significant surface water and porewater acidity, and the mobilisation of toxicants, negatively impacting proximal ecosystems and infrastructure. In this thesis I argue that the Millennium Drought acidification event provides a test case globally for how meteorological drought triggers extreme CASS oxidation, and how other variables can exacerbate the issue. I therefore present a systemic investigation of CASS acidification within the RME and identify the boundary conditions and exogenous variables that control acidification risk. Elements mobilised from oxidised CASS (Fe, Mn, Al, V, Cr, Co, Ni, Cu, Zn, Cd, Pb, and REE) are accumulating in the sediments of the RME, and spatial patterns of enrichment and REE fractionation can be used as environmental tracers of acidic drainage. Transport and accumulation of these elements is controlled by hydrodynamic and geomorphic processes in the estuary. Multiple depositional regimes apparent in the sediment record show that hydrodynamic and geomorphic processes have, however, changed during the history of the RME in response to sea-level and anthropogenic impacts, impacting the formation of CASS and the likelihood of extreme acidification within the system. Adopting a systems approach, it is apparent that the extremity of the Millennium Drought acidification event was intensified by factors other than drought, and that the triggering of extreme CASS acidification often exhibits a non-linear relationship to boundary condition changes, meaning negative impacts can be sudden and disastrous. Wave-dominated estuaries are particularly vulnerable systems, and changes predicted for an anthropogenically heated future will likely shift estuarine systems closer to thresholds where severe acidification can be expected.
15
Hartwig, Lana D. "Aboriginal water rights in New South Wales: Implications of water governance reform for self-determination." Thesis, Griffith University, 2020. http://hdl.handle.net/10072/393199.
Full textAbstract:
Over recent decades, Indigenous peoples’ claims for rights to govern, protect and benefit from the use of their waters have attracted increased global attention. These claims form part of a broader set of demands for Indigenous self-determination, now enshrined in international norms, including the United Nations Declaration on the Rights of Indigenous Peoples. However, Indigenous peoples’ struggles for self-determination broadly, and freshwater rights specifically, are contentious and complex. This is especially so in settler-colonial contexts where Indigenous and settler populations and their institutions and political systems co-exist in complicated and interconnected ways.
Over roughly the same period, we have also witnessed the transformation of freshwater governance internationally. Underpinned by neoliberal rationality, nation states have tended to frame water governance challenges as issues of scarcity and inefficiency, and have proffered predominantly market-based and demand-focused policy and legislative responses. Scholars and practitioners disagree about whether these neoliberal water governance and distribution approaches create opportunities or further obstacles for appropriately addressing Indigenous freshwater claims. Some are concerned about how neoliberal rationality masks power asymmetries and constructs water as (only) an economic and value-free resource, which may displace alternative ontological and material water realities that do not align with dominant neoliberal representations of water.
These arguments about the pros and cons of neoliberal water governance and water markets play out in Australia. Over the past twenty years, escalating Aboriginal claims for freshwater rights have coincided with widespread neoliberal water reforms. These reforms have led to the development of the world’s biggest water market and completely restructured water rights. Despite this, Aboriginal peoples’ water justice claims remain unresolved and little is known about how neoliberal water governance and market frameworks materially or otherwise affect Aboriginal peoples in this region.
In response, this thesis describes and analyses the effects of Australia’s neoliberal water governance on self-determination for Aboriginal peoples. It uses the New South Wales portion of the Murray-Darling Basin, Australia’s most productive agricultural region, as a case study to examine the experiences of Aboriginal peoples who seek rights to access, use and manage water. Theoretical insights from critiques of neoliberalism, settler-colonial theory, legal and ontological pluralism and Indigenous methodologies informed the methodological approach to conceptualising and responding to this research problem. Data was collected via semi-structured interviews with Aboriginal water policy experts and representatives from Aboriginal organisations across the case study area that hold statutory water entitlements, as well as archival, documentary and state water entitlement data analysis.
The two key interrelated arguments and findings of this study are as follows. First, the neoliberal governance regime under which Aboriginal peoples currently seek water access and self-determination is built upon and entrenches the exclusion of Aboriginal peoples from historical land and water governance. Aboriginal peoples’ abilities to access, freely care for, manage and determine the use of water are significantly curtailed by enduring settler-colonial power relations. Evidence of this is obtained by quantifying and analysing Aboriginal-held water entitlements, establishing a profile of current holdings, and showing changes to these holdings over time. Analysis of interviews with Aboriginal water policy experts about their experiences and struggles to secure Aboriginal water rights in the recent era also support this finding.
Second, this thesis finds that where Aboriginal entities hold commercially valuable statutory water entitlements, there are some opportunities for self-determination but these are generally limited and constrained by structural, organisational and wider governance factors. Analysis of attitudes and behaviours of Aboriginal organisations and representatives who trade in the water market reveals that the conditions that arise from neoliberal water governance (and its intersection with neoliberal Aboriginal affairs policies) encourage them to conceptualise themselves, their water property rights and their pathways to self-determination, in particular ways that align with market subjectivities. This has the effect of narrowing the magnitude and suite of benefits that Aboriginal organisations derive from holding rights to water.
The findings from this work present important and timely insights for policy and law reform processes currently underway across Australia. The findings also offer valuable insights for Aboriginal organisations seeking to better engage with water governance and wanting to utilise and manage their water in ways of their choosing.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>School of Environment and Sc<br>Science, Environment, Engineering and Technology<br>Full Text
16
Judge, David, and n/a. "The Ecology of the polytopic freshwater turtle species, Emydura macquarii macquarii." University of Canberra. Resource, Environmental and Heritage Sciences, 2001. http://erl.canberra.edu.au./public/adt-AUC20050418.151350.
Full textAbstract:
An ecological study of Emydura macquarii macquarii in the south-east region
of Australia was conducted between October 1995 and March 1998. E. m. macquarii is
an abundant and widespread species of short-necked turtle that is highly variable in
morphology and related life history attributes. No study in Australia had previously
looked at geographic variation in biological traits in freshwater turtles, hence the level
of variation in E. m. macquarii had been poorly documented. The principal aims of this
study were to investigate the plasticity of life history traits across populations of E. m.
macquarii and to speculate on possible causes. A more intensive study was also
conducted on a rare and suspected declining population of E. m. macquarii in the
Nepean River to determine whether relevant management and conservation measures;
were required.
The study involved comparing various life history attributes between five
populations of E. m. macquarii (Brisbane River, Macleay River, Hunter River, Nepean
River and Murray River). The populations were specifically chosen to account for the
range of variation in body size within this subspecies. Body size (maximum size, size at
maturity, growth rates), population structures (sex ratios, age and size structures),
reproductive traits (clutch mass, clutch size, egg size, egg content, etc.) and other
attributes were collected for each population. Patterns of life history traits, both within
and among populations, were explored so that causes of variation could be sought.
Geographic variation in Body Size and other Related Life History Traits
Body size in E. m. macquarii differed markedly between populations. Females
ranged in maximum sizes (carapace length) of 180 mm in the Macleay River to over
300 mm in the Murray River. E. m. macquarii was sexually dimorphic across all
populations with females larger than males in all cases. Maximum body size was
positively related to the size at which a turtle matures. The size at maturity in turn was
positively related to juvenile growth rates. Age was a more important factor for males
in terms of timing of maturity whereas in females it was body size. Morphological
variation was not only great between populations, but also within populations.
Maximum body size was unrelated to latitude; hence it was inferred that habitat
productivity had the most important influence on geographic variation in body size.
Population structures also differed between populations. Sex ratios did not differ in the
Brisbane, Macleay and Murray Rivers. However, a male bias was present in the Nepean
River population and a female bias in the Hunter River. Juveniles were scarce in the
Brisbane and Macleay Rivers but numerous in the Nepean and Hunter Rivers.
Geographic Variation in Reproduction
There was large variation in reproductive traits across populations of E. m.
macquarii. Nesting season began as early as mid-September in the Brisbane River and
as late as December in the Hunter River, and continued until early January. Populations
in the Hunter and Murray Rivers are likely to produce only one clutch per season while
populations from the Macleay and Nepean Rivers can produce two, and on some
occasions, three clutches annually. The majority of females would appear to reproduce
every year.
Clutch mass, clutch size, and egg size varied greatly both within and among
populations. A large proportion of variation in reproductive traits was due to the effects
of body size. E. m. macquarii from large-bodied populations such as in the Brisbane
and Murray Rivers produced bigger eggs than small-bodied populations. Within a
population, clutch mass, clutch size, and egg size were all correlated with body size,
except the Nepean River. The variability of egg size was smaller in large-bodied
populations where egg size was more constant.
Not all variation in reproductive traits was due to body size. Some of this
variation was due to annual differences within a population. Reproductive traits within
a population are relatively plastic, most likely a result of changing environmental
conditions. Another source is the trade-off between egg size and clutch size. A negative
relationship was found between egg size and clutch size (except the Brisbane River).
Reproductive variation was also influenced by latitudinal effects. Turtles at lower
latitudes produces more clutches, relatively smaller clutch sizes, clutch mass and larger
eggs than populations at higher latitudes. Annual reproductive output is greater in
tropical populations because they can produce more clutches per year in an extended
breeding season.
Eggs that were incubated at warmer temperatures hatched faster and produced
smaller hatchlings. Incubation temperatures above 30�C increased egg mortality and
hatchling deformities, suggesting this is above the optimum developmental temperature
for E. m. macquarii. Hatchling size was positively related to egg size, hence hatchling
sizes was on average larger in the Murray and Brisbane rivers. However, population
differences remained in hatchling size after adjustments were made for egg size. For
example, hatchlings from the Hunter River were smaller than those from the Macleay
River despite the egg size being the same. These differences were most likely due to the
shorter incubation periods of hatchlings from the Hunter River.
Nepean River
The Nepean River population of E. m. macquarii is at the southern coastal limit
of its range. This is a locally rare population, which is believed to be declining. This
study aimed at determining the distribution, abundance, and population dynamics to
assess whether any conservation management actions were required. E. m. macquarii in
the Nepean River was mainly concentrated between Penrith and Nortons Basin,
although even here it was found at a very low density (10.6 - 12.1 per hectare). The
largest male caught was 227 mm while the largest female was 260.4 mm. Males
generally mature between 140 - 150 mm in carapace length and at four or five years of
age. Females mature at 185 -195 mm and at six to seven years of age.
Compared with other populations of E. macquarii, Nepean River turtles grow
rapidly, mature quickly, are dominated by juveniles, have a male bias and have a high
reproductive output. Far from being a population on the decline, the life history traits
suggest a population that is young and expanding. There are considered to be two
possible scenarios as to why the Nepean River population is at such a low density when it appears to be thriving. The first scenario is that the distribution of the population on
the edge of its range may mean that a small and fluctuating population size may be a
natural feature due to sub-optimal environmental conditions. A second scenario is that
the population in the Nepean River has only recently become established from dumped
pet turtles.
17
Peterson, Kylie, and n/a. "Environmental impacts on spawning and survival of fish larvae and juveniles in an upland river system of the Murray-Darling Basin." University of Canberra. Resource, Environmental & Heritage Sciences, 2003. http://erl.canberra.edu.au./public/adt-AUC20060713.121419.
Full textAbstract:
Six rivers within the upper Mumbidgee catchment were sampled for larval and juvenile
fish. The rivers represented both regulated and unregulated flow regimes and varied widely in
size. There was wide variation in the larval fish communities supported by each river, both in
terms of the species diversity and total abundance of fish sampled. The highly regulated reach
of the Mumbidgee River sampled during this study had the highest numbers of native
species and native individuals of any river sampled.
In the two rivers selected for further study, the Murmmbidgee and Goodradigbee, there was a
high level of inter-annual consistency in the species composition within the reaches sampled,
despite considerable change in the temperature and flow regimes of both rivers. This indicates
that at least some spawning of those species sampled may occur each year, regardless of
environmental conditions. Estimates of the relative abundance of each species sampled
changed markedly between years, and it is argued, on the basis of growth information
contained in the otoliths, that differential survival of larvae and juveniles was largely
responsible for this shift in relative abundance.
Otolith microstructure provided information on the date of spawning and early growth patterns
of all species sampled in the upper Mumumbidgee catchment. In addition to determining the
age and thus 'birth-date' of an individual, the effect of a particular event or series of events has
on growth, and subsequent survival, is permanently recorded in the otolith microstructure.
This enables accurate back-calculation and correlation to management actions or natural
events. No other research tool has this ability to retrospectively assess, on a daily basis, the
impacts of management actions on condition and subsequent survival of fish larvae.
Species sampled could be separated into three groups based on spawning requirements; those
linked with flow, those linked with temperature and generalist species that appear to have river
independent cues, such as photoperiod or moon phase.
Patterns in growth rate during the early life history stages enabled quantification of the
consequences of variation in environmental conditions on the survival and recruitment of
various species. Growth was not always highly correlated with water temperature, in fact, for
mountain galaxias, high temperatures appear to negatively affect larval condition and
subsequent survival. Conversely, carp exhibited a strategy more consistent with common
perceptions, with growth and survival increasing with increasing temperature.
The study uncovered spawning and growth patterns that were unexpected. Age analysis of
western carp gudgeon demonstrated that they had undertaken a mid-winter spawning, when
the water temperature in the main channel was far lower than that at which spawning was
previously recorded for this species. Redfin perch from the unregulated Goodradigbee River
exhibited growth rates exceeding the published upper limits for this and other closely related
species. This growth could not be correlated with either temperature or flow, indicating that
there are additional factors that dominate growth rates of redfin perch in the Goodradigbee
River.
The proportion and abundance of native species alone is not necessarily indicative of a
'healthy' or pristine system; some native species may be positively affected by river
regulation, at least as juveniles. Comparison of the current larval fish community with likely
pre-European fish communities does provide an indication of change to the system. The
results of this study suggest that larval fish growth rates can be strongly influenced by
environmental conditions, thus providing a powerful tool for monitoring future change and the
factors which cause it.
This study has demonstrated the value of larval and juvenile fish age and growth information,
derived from otolith microstructure techniques, for many aspects of river management.
Current river management priorities for which these techniques provide unique information
include the determination of environmental flow regimes and the control of undesirable exotic
species such as carp.
18
Burdack, Doreen [Verfasser], and Hans-Georg [Akademischer Betreuer] Petersen. "Water management policies and their impact on irrigated crop production in the Murray-Darling Basin, Australia / Doreen Burdack ; Betreuer: Hans-Georg Petersen." Potsdam : Universität Potsdam, 2014. http://d-nb.info/1218861746/34.
Full text
19
Chotipuntu, Piyapong, and n/a. "Salinity sensitivity in early life stages of an Australian freshwater fish, Murray cod (Maccullochella peelii peelii Mitchell 1838)." University of Canberra. Resource, Environmental & Heritage Sciences, 2003. http://erl.canberra.edu.au./public/adt-AUC20060331.115030.
Full textAbstract:
The Murray cod (Maccullochella peelii peelii Mitchell 1838) is Australia�s largest freshwater fish. Once highly abundant in the Murray-Darling river system, populations have drastically declined in recent decades. Many causes for this decline have been proposed, including over-fishing, habitat loss and altered river flow regimes. This study hypothesised that elevated salinities have led to selective mortality in some developmental stages, which have in turn depleted stock recruitment and adult populations. The objectives of this study were to determine the optimal, threshold, upper sublethal and lethal salinities for development of eggs, yolk-sac larvae, fry and fingerlings of M. peelii peelii. Investigation the impact of salinity on fertilisation utilised gametes of trout cod (M. macquariensis, Cuvier 1829) instead of M. peelii peelii. Studies were carried out in a controlled laboratory environment using test media prepared from commercial sea salt. The results showed that the eggs of the trout cod hatched only when fertilised and incubated in freshwater, and only larvae hatched in freshwater survived through the yolk absorption period of 12 days. Yolk utilisation efficiencies were not significantly different among the salinities of 0-0.30 g/L. There was no effect of pre- or post- fertilising processes on the salinity tolerances of yolk-sac larvae. No larvae survived at salinities higher than 0.30 g/L during the yolk utilisation period. Lethal salinity concentration in Trout cod and Murray cod larvae was exposure time dependent. The 1 day LC50 of the larvae was 1.97 and 2.33 g/L respectively, compared with the 12 day LC50 values of 0.50 and 0.35 g/L respectively. The threshold (no effect level) salinities of larvae of Trout cod and Murray cod were 0.46 and 0.34 g/L respectively at 12 days exposure. The salinity sensitivities of fry of Murray cod were moderated by increasing pH between pH 6.2 and 8.8, and stimulated by increasing temperatures from 15 to 30°C. The optimal salinity was only slightly affected by temperature. The threshold and upper sublethal salinities varied slightly depending on feeding regime. The salinity sensitivities of fingerlings of Murray cod
were: LC50 = 13.7 g/L; optimal salinity from 4.6 to 5.0 g/L ; threshold salinity from 5.9 to 7.4 g/L, and upper sub-lethal salinity from 9.2 to 9.9 g/L � with the range in all cases affected by acclimation period salinity. The blood osmolality at LC50 of the fingerlings was 444 mOsmol/kgH2O or equivalent to 14.2 g/L, and the dehydration rate was 4.8%. The osmolality increased significantly in salinities higher than 9.0 and 6.0 g/L when fish were exposed for a period of 1 day and 41 days respectively. The oxygen consumption increased significantly in salinities higher than 8.0 g/L. Distortion of the notochord and corrosive skin syndrome were major symptoms describing sub-lethal effects found in the embryos, and fry and fingerlings of Murray cod respectively. Noting the risks of extrapolating directly from laboratory to field conditions, it is predicted that when salinity in natural habitats increases above 0.34 g/L a significant impact on Murray cod recruitment will result.
20
Topaloglu, Ece. "Privatization Of Water Utilities From And Integrated Water Resources Management Perspective." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609172/index.pdf.
Full textAbstract:
This submission reviews the two successful examples of water markets, one in the developed world, the Murray Darling Basin in Australia and other in the developing world, the Limari Basin case in Chile respectively. Of central importance, we find the commodification of a natural resource, water, through a process of the progressing neoliberal agenda. As regards the outcome of this process in these two cases<br>while on the one hand the water markets have contributed to a more efficient allocation of water resources from less efficient to more efficient uses, on the other hand, problems related to environmental degradation in the former case and the social inequity in the latter have been unable to be solved.
21
Rayl, Johanna M. "Water Markets and Climate Change Adaptation: Assessing the Water Trading Experiences of Chile, Australia, and the U.S. with Respect to Climate Pressures on Water Resources." Scholarship @ Claremont, 2016. http://scholarship.claremont.edu/pomona_theses/150.
Full textAbstract:
Water trading and water markets have been listed by leading climate change organizations as a possible tool for climate change adaptation. Experience with water trading exists in many places in the world, and three of the most well-known and widely-studied markets for water rights are found in the Western United States, Chile, and Australia's Murray-Darling Basin. While the body of literature on the performance of these markets is extensive, few papers relate the experiences of these three countries to adaptation as of yet. This thesis seeks to report on the outcomes of water markets in three cases with special attention to the following adaptation questions: Can water markets be a tool to address increasing variability in water supply; and what are the necessary environmental, political, and historic conditions for a market to be successful in allocating water resources under situations of scarcity? The experiences of these three cases yield the following conclusions about the use of water markets in climate change adaptation: the degree of existing infrastructure for water storage and transportation must be considered in the implementation of markets; water markets must be continually revised to internalize local third party effects; transaction costs must be minimized if markets are to serve increased short-term variability in water supply; sustainable outcomes are most readily met when markets approximate “cap-and-trade” programs; and the involvement of local institutions in market design will support market activity and the achievement of localized adaptation goals.
22
Eberhard, Rachel. "The metagovernance of Australian water policy: Practices, rationales and outcomes." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/118143/1/Rachel_Eberhard_Thesis.pdf.
Full textAbstract:
This thesis examines how governments work with stakeholders to develop and implement water policy in Australia. Evidence from the Great Barrier Reef and the Murray Darling Basin showed the challenges involved, and how this can affect environmental outcomes. Results show how government can work more effectively with stakeholders, and the potential of non-government organisations to help broker better policy outcomes.
23
Timms, Wendy Amanda Civil & Environmental Engineering Faculty of Engineering UNSW. "The importance of aquitard windows in the development of alluvial groundwater systems : Lower Murrumbidgee, Australia." Awarded by:University of New South Wales. School of Civil and Environmental Engineering, 2001. http://handle.unsw.edu.au/1959.4/18671.
Full textAbstract:
Variable groundwater quality in complex aquifer-aquitard systems presents a challenge for sustainable groundwater development. In the Lower Murrumbidgee alluvial fan of the Murray-Darling Basin in semi arid inland Australia, shallow groundwater is saline (12000 µ S/cm) and locally contaminated by nitrate. Deep fresh aquifers (150 µ S/cm), developed as an irrigation water supply, were thought to be protected from downwards leakage by laterally extensive aquitards. However, hydrochemical sampling, augmented by historic data, revealed that aquifer salinisation (400 to 4000 µ S/cm) had occurred at some sites to 50 m depth since the mid 1980s. Aquitard windows, landscape depositional features at a scale of 10s to 100s of metres which are rarely detected by conventional investigations, were proposed as conduits for rapid downwards leakage in stressed systems. Intensive research was conducted at the Tubbo site where downhole geophysical logging and minimally disturbed cores were used to describe a saline clayey silt to 15m depth, an indurated clayey sand and 2 deep deposits of hard clayey silt. Fracturing was inferred by the scale dependency of aquitard permeability (Kv 10E-11 to 10E-6 m/s). Lithological variation near the surface was delineated by electrical imaging which revealed a 40m wide aquitard window beneath a veneer of smectite clay. Intensive monitoring of groundwater pressures in six piezometers (23-96 m depth) near the Tubbo irrigation bore and two other peizometers upgradient, indicated that the indurated clayey sand formed an effective hydraulic barrier but the deep silty deposits were spatially discontinuous. Groundwater samples were collected before, three times during, and after the 1998-99 irrigation season. A large, but delayed TDS increase occurred in the shallow aquifer and small pulses of saline water were sustained in the middle aquifer but shortlived in the deep aquifer. Hydrochemical and isotopic data dC-13, dH-2, dO-18, C-14 and H-3) showed the middle aquifer mixing with the deep aquifer, though retaining the signature of a palaeowater. Hydrochemical changes were accounted for with PHREEQC inverse mass balance models for the shallow aquifer. Mixing of aquifer water with 20-70% saline porewater from the upper aquitard occurred, together with ion exchange and NaCl dissolution. Based on an axisymmetric radial FEFLOW model, 5-30% of the volume pumped was accounted for by vertical leakage from the middle aquifer. Leakage from the shallow aquifer was small but significant, as it allowed high salinity water to migrate. Permeability and compressible storage measurements (Ss 10E-5 to 10E-4 /m) were used to constrain model calibration, and to show that direct mixing occurred mainly via aquitard windows at depth, and between the shallow and middle aquifers via leaky boreholes. Fracture flow and aquifer-aquitard interaction by diffusion were of secondary importance.
24
Barbour, Emily. "Quantitative modelling for assessing system trade-offs in environmental flow management." Phd thesis, Canberra, ACT : The Australian National University, 2015. http://hdl.handle.net/1885/109583.
Full textAbstract:
This research aims to better enable the management of environmental flows through exploring the opportunities and challenges in using quantitative models for decision making. It examines the development and application of ecological response models, river system models, and multi-objective optimisation for improved ecological outcomes and the identification of trade-offs. In doing so, the thesis endeavours to capture a deeper and more holistic understanding of uncertainty in the application of quantitative models, to assist in making more informed decisions in water resource management. The thesis includes three main components. Firstly, an ecological response model is developed to advance previous methods by: (1) adopting a systems approach to representing water availability for floodplain vegetation, considering rainfall and groundwater in addition to riverine flooding; (2) including antecedent conditions in estimating current ecological condition; and (3) including uncertainty in modelling ecological response through the use of upper and lower prediction bounds and multiple conceptual models derived through expert elicitation. Secondly, the ecological response model is evaluated using sensitivity and uncertainty analysis. Global sensitivity analysis was used to identify model components that are both uncertain and have critical impact on results, and demonstrated that conceptualisation of ecological response had the greatest impact on predicted ecological condition. A novel application of Bayesian analysis was then used to evaluate different expert derived models against observed data, considering multiple sources of uncertainty. The analysis demonstrates a number of remaining challenges in modelling ecological systems, where model performance depends upon assumptions that are highly uncertain. The third and final component evaluates opportunities and challenges in using multi-objective optimisation, to assist in water resource management and the improvement of ecological outcomes. This component begins with a synthesis of previous studies drawing upon literature from hydrology, ecology, optimisation and decision science, and identifies a number of strategies for improvement. The synthesis is followed by a case study on the Lachlan catchment of the Murray-Darling Basin, Australia. The case study uses multi-objective optimisation to explore different environmental flow rules using a river system model combined with the expert-based ecological models. In doing so, it addresses the challenges of objective setting and problem framing in the context of significant uncertainty. The case study evaluates results generated using the optimisation framework in terms of likely actual decision outcomes. The research identifies a need to revisit fundamental questions regarding system understanding and objective framing in the light of rapidly improving computational capacity and sophistication. This is particularly relevant in the case of ecological management, where objectives form an interplay between ecological science and social values. Modelling tools provide valuable pathways to system learning and communication, yet a deeper understanding and evaluation of model behaviour in the context of actual decisions is needed. The methods presented in this thesis aim to provide a step toward addressing the challenges of working with uncertain information, incomplete knowledge, and integration across multiple disciplines within a decision-making environment. Through the methods developed here, the research seeks to advance the science of model development and application.
25
Patrick, Marian J. "Scale and justice in water allocation." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2012. https://ro.ecu.edu.au/theses/474.
Full textAbstract:
Water allocation is a fundamental part of water resources management. Water allocation is often a contested process because it involves multiple uses and users of water. Issues of justice arise when resources are, or are perceived to be, in short supply. When water is allocated the rules for the distribution of the resource may result in just outcomes for some stakeholders but may create injustices for other stakeholders. Issues of scale thus form an important component of water allocation. This thesis draws from an amalgam of ideas on justice, scale and water management and aims to present a conceptual framework that explicitly utilises an understanding of scale and levels as a means to enrich the concept of justice in the context of the water allocation. The discovery that there was no existing conceptual framework described in the literature that explicitly addressed and defined water, scale and justice simultaneously and in sufficient depth revealed the necessity to develop such a framework hence providing the primary impetus for this study.
Two scales – a regulatory and an institutional scale – were identified using a specific issue facing water management within the Murray-Darling Basin in Australia, namely Domestic and Stock (D&S) dams. The management of D&S dams currently falls outside the formal water entitlement framework for the Basin and presents a scenario of perceived injustice in that water share holders pay for their water and rely on it for their livelihoods while those accessing water for D&S use do not pay for it and often it is for aesthetic purposes. Five levels within the regulatory and institutional scale were found to be relevant to this issue and comprised the federal, basin, state, regional and local levels. These levels described the boundary of the system under investigation and they defined the scope of the study. They also provided the means to identify the relevant legislation, strategy and policy documentation at each level within the regulatory scale and the relevant institutions and key decision makers that were interviewed at each level in the institutional scale.
Content analysis techniques were used to examine five regulatory documents and ten interview transcripts; one document from each of the five levels within the regulatory scale and two interviewees from each of the levels within the institutional scale formed the primary data source for the study. The texts were coded, categories were identified, ideas were clustered and three themes were developed. These themes were entitled: Broadening the Scope of Justice; A Continuum of Justice and The Dynamics of Justice. Each of these themes provided a different perspective of justice and contributed to the development of a conceptual framework entitled The Cycles and Spirals of Justice.
This study explored justice through the lens of the issue of Domestic and Stock (D&S) dams. The issue of D&S dams was taken up by a number of institutions and addressed via a number of policies and regulations. As it moved through the various levels of the regulatory and institutional scales it was perceived to be dealt with justly by some and resulting in injustices by others. Justice is in the eye of the beholder! Politics and power shifted the D&S issue around the system; it was reframed by institutions along the way to suit their mandates and their cause. What was deemed as a just way of dealing with D&S dams at one level was deemed unjust at another.
Three justice for whom categories were identified and explored through the case study, namely justice for social, economic or environmental concerns. They were found to vary between the levels of the regulatory and institutional scale and their positions on each scale shifted under extreme water scarce conditions. The case study illustrated the interdependency of social, economic and environmental concerns, the need to be fully inclusive of all three concerns within a scope of justice.
Striving for or managing for justice is not a static act; if justice is achieved at one level, it might not be at another. What is often perceived as a just outcome at one level of one scale could result in injustices at another level or scale. It is important to recognise that there exists at each level a cycling continuum of justice and injustice, and that because we are dealing with issues in a complex system we need to be cognisant of the relationship between justice and injustice in the decision making process. There exists a distinct possibility that we might be unaware of the injustices that our actions at one level might have at another. I have developed a conceptual framework entitled the Cycles and Spirals of Justice that helps make sense of the relationship between justice and injustice in the context of the water allocation decision making by explicitly utilising an understanding of scale and levels.
This is a transdisciplinary study so it is hoped that the findings of this research will contribute to building bridges between disciplines, enhance the current understanding of the concepts of justice and scale in the context of water allocation and ultimately contribute in some small way to water being used and distributed more justly and sustainably in the future.
26
Molinari, Claire Marcella. "The environment, intergenerational equity & long-term investment." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:30dd270b-3f0f-4b8b-979e-904af5cb597b.
Full textAbstract:
This thesis brings together two responses to the question ‘how can the law extend the timeframe for environmentally relevant decision-making?’ The first response is drawn from the context of institutional investment, and addresses the timeframe and breadth of environmental considerations in pension fund investment decision-making. The second response is related to the context of public environmental decision-making by legislators, the judiciary, and administrators. Three themes underlie and bind the thesis: the challenges to decision-making posed by the particular temporal and spatial characteristics of environmental problems, the existence and effects of short-termism in a variety of contexts, and the legal notion of the trust as a means for analysing and addressing problems of a long-term or intergenerational nature. These themes are borne out in each of the four substantive chapters. Chapter III sets out to demonstrate the theoretical potential of pension funds to drive the reduction of firms’ environmental impact, and, focusing particularly on the notion of fiduciary duty, explores the barriers that stand in their way. Chapter IV provides a practical application of the theoretical recommendations outlined in its predecessor. It provides a framework outlining how pension funds might implement a longer term, more sustainable approach to investing. The second half of the thesis, operating in the context of public environmental decision-making, is centred upon a particularly poignant legal notion with respect to the environment and time: the concept of intergenerational equity. Just as the first half of the thesis deals with the timeframes relevant to investment decision-making by pension funds within the bounds of fiduciary duty, largely a private law affair with public implications, the second half of the thesis is concerned with the principle of intergenerational equity as a means for extending the decision-making timeframe of legislative, judicial and administrative decision-makers. As previous analyses of the concept of intergenerational equity provide little insight into its practical implications when applied to particular factual situation, Chapter V sets out the structure of the principle of intergenerational equity as revealed by case law. Chapter VI brings together the issues from the first three papers by conceptualising intergenerational equity in resource management as an issue of long-term investment. Long-term environmental decision-making faces many obstacles. Individual behavioural biases, short-term financial incentive structures, the myopic pressures of the electoral cycle and the tendency of the common law to reinforce the (often shorttermist) status quo all present significant barriers to the capacity of both private and public decision-makers to act in ways that favour the longer term interests of the environment. Nonetheless, this thesis argues that there is reason for hope: drawing upon the three themes that underlie all of the substantive Chapters, it articulates potential legislative changes and recommends the adoption of particular governance structures to overcome barriers to long-term environmental decision-making.
27
Srivastava, Sanjeev Kumar. "Predicting freshwater fish distribution in the Murray-Darling Basin." Phd thesis, 2005. http://hdl.handle.net/1885/150853.
Full text
28
McDonald, John Gilbert Walton. "Hydrochemical processes in the Lower Murrumbidgee Area, NSW : the influence of weathering reactions, evaporation, and salt dissolution on groundwater quality." Master's thesis, 2014. http://hdl.handle.net/1885/150008.
Full textAbstract:
The Lower Murrumbidgee area is a major agricultural region located on the Eastern margin of the sedimentary Murray Basin. A large low-salinity groundwater body extends from the Eastern margin in the semi-confined Calivil and Renmark Formation aquifers, and is overlain by higher salinity water in the surficial Shepparton Formation. Deep groundwater extraction has increased to ~300 GL in last decade, leading to substantial pressure declines, and the resulting increased vertical hydraulic gradient increases the potential for downward migration of saline water into productive aquifers. This study is aimed at determining the processes that form the wide range of groundwater compositions in the Lower Murrumbidgee area, and using groundwater chemistry to constrain flow paths. Groundwater and surface water were collected from bores and rivers and analysed for major and minor element concentrations, 87Sr/86Sr, and deuterium/oxygen isotope ratios. Total dissolved solids in groundwater samples span 3 orders of magnitude. Low-salinity groundwaters have similar major ion ratios to the surface waters, with high proportions of HCO3, Na, and Ca, whereas high-salinity waters are Na-Cl dominated with ionic ratios and concentrations similar to seawater. The location of the study area and the groundwater 87Sr/86Sr ratios preclude mixing with connate seawater; groundwaters instead evolve from low-salinity recharge sources (surface water and rain). Major ion trends indicate that high-salinity groundwaters are formed through evaporation/transpiration of rainfall during recharge, and that concentration of dilute solutes initially delivered in rainfall is the dominant process that forms chloride-rich saline groundwaters. The high potential evapotranspiration and flat topography (low runoff) result in removal of a large fraction (>99%) of the water and retention of the most soluble solutes (i.e., Na, Cl, Br). Dissolution of aeolian halite-containing dust is a secondary source of chloride to the system, contributing up to 30% of the total in the east of the study area and 50% in the west, but can not alone account for the formation of the saline groundwater. The shift to Na-Cl dominated compositions during concentration is instead caused by precipitation of calcite and high-Mg calcite; these less soluble components are then recycled back into the atmosphere and influence the rainfall compositions. Cation exchange of dissolved Na for Ca appears to occur during concentration, allowing continued precipitation of calcite without depletion of Ca/accumulation of HCO3. The lowest salinity groundwaters are clustered around the Murrumbidgee River at the eastern margin, and have similar major ion ratios to river water but higher Si concentrations and lower 87Sr/86Sr, indicating that weathering reactions occur during/shortly after recharge. Plagioclase and carbonate fractions of the sediments appear to weather preferentially, because groundwater 87Sr/86Sr ratios are significantly lower than bulk ratios of Murray Basin sediments and their source rocks. The more saline compositions of the deep groundwaters in the west of the study area are consistent with mixing with shallow saline water through downward leakage. The salinity increase is most marked 150-200 km west of the basin margin, and is likely related to increased sediment thickness and a resulting decrease in horizontal flow rates.
29
Ogden, Ralph Winston. "The impacts of farming and river regulation on billsbongs of the Southeast Murray Basin, Australia." Phd thesis, 1996. http://hdl.handle.net/1885/110241.
Full textAbstract:
This thesis is an investigation into the effects of farming and river regulation on
billabong (floodplain lake) ecology. The study region is in the southeast comer of the
Murray-Darling Basin. Billabongs comprise a significant natural freshwater lake system
in the one million km2 drainage basin dominated by semi-arid conditions. The region
was settled by Europeans in the middle 1800's, and early farming, activities, mainly the
running of cattle and sheep, were particularly intense. Extensive timber extraction also
occurred at this time. Both these activities have probably declined to a degree since the
early 1900's but are practised in the region today. Fertiliser use became widespread in
the 1930's. River regulation did not begin in earnest until the construction of the Hume
Dam in 1930. In the study region regulation has decreased monthly variation in river
flows, mainly by maintaining unnaturally high flows during summer irrigation
demand, increased daily flow variability with short-term releases, decreased the
frequency of minor flooding, slightly increased flood duration, and decreased sediment
loads near weirs. These and other impacts of European settlement on the regional
landscape are profound, and may have an effect on billabong limnology.
Concepts of disturbance ecology are used as a framework for assessing changes to the
biota living in billabongs resulting from European settlement. Two complementary
lines of evidence are followed, one physicochemical and one biological, and evidence
for the impacts of farming and regulation is sought from both historic and present day
patterns of limnology.
The limnology of 43 billabongs influenced to varying degrees by farming and
regulation were surveyed every 2 months over a 15 month period. The billabongs vary
in mean depth from about 0.3 to 4.5 m, and significant fluctuations in depth occur, both
seasonally and between wet and drought periods. Natural variation in total nitrogen,
total phosphorus, turbidity, and secchi depth billabongs is marked and dominated by
temporal factors; mainly fluctuations in depth accompanying seasons and droughts,
but also flooding. Significant shorter-term temporal variation is also implied from the
data. In contrast, natural variation in pH is minor and salinity is always low. Maximum depth is the only systematic source of natural spatial variation revealed, apart from a
slight east-west shift in major ion balance; the main determinants of nutrient limnology
and light environment of billabongs found in this study are temporal factors. Since
natural variation in physicochemistry is dominated by relatively cyclical factors
(seasons and floods), much natural disturbance in billabongs appears to be of the pulse
variety, and to be moderately to highly predictable. It is likely the biota have evolved
adaptations for this variation.
Farming only affects phosphorus and salinity, but the effect on phosphorus is minor in
comparison to natural variation, and salinity levels remain low. In contrast, river
regulation has important direct effects on billabong depth, which on the decadal scale
translates to billabong permanence. The indirect effects of regulation on nutrients and
the light environment, from effects on depth, are likely to equal natural variation.
However, most of the anthropogenic variation mimics natural variation, and the biota
may already possess the adaptations to deal with it (may be 'preadapted'). The pattern
of rapid depth fluctuations and summer flooding of low-lying billabongs created by
regulation is 'new' to the ecosystem, at least in the current climatic regime, and the
biota may not cope as well with this.
Based on the skeletal remains of Cladocera in the surface sediments of 41 billabongs,
farming and river regulation cause a relatively minor impact on the cladoceran fauna.
Farming and regulation both affect some uncommon species, and regulation affects the
overall diversity, richness and equitability of assemblages. Farming therefore has less
of an effect than regulation, which is consistent with the patterns of physicochemistry
observed. However, on the whole, assemblages from farmed and regulated billabongs
are not very different from those in billabongs remote from farms and on unregulated
river reaches, suggesting that the Cladocera are 'preadapted' to anthropogenic
environmental variation by relatively high natural variation in physicochemistry.
The above conclusions of no or low impact of farming and regulation on billabongs
rely on billabongs remote from farms and on unregulated river reaches being
unimpacted by these land use activities. This assumption is tested by examining the
historical sedimentary record of billabongs. The historical record of physicochemistry in 8 billabongs was examined. Sedimentation
rates are currently about 5 mm per year, but have increased by an order of magnitude
since settlement. Based on the stratigraphy of sediment structure, organic matter
content, and the atomic ratio Fe:Mn, redox conditions have changed in a minimum of 4
billabongs and a maximum of 6 since settlement. These include billabongs on
unregulated river reaches and presently distant from farms. The direction of change is
usually towards more oxidising conditions, but it is possible that the interpretation of
the direction of changing redox (as distinct from the occurrence of changing redox) has
been corrupted by the higher sedimentation rates following settlement. External
phosphorus loading has, if anything, declined since settlement, but it is more likely that
no change has occurred at all and that the patterns of phosphorus are due to the
changing redox conditions. Because redox conditions have changed in billabongs
considered as low-impact controls, assessments of impact based on the present day
limnology of billabongs may underestimate the effects of farming and river regulation.
The historical record of both Cladocera and the extent of macrophyte cover are inferred
from the stratigraphy of cladoceran assemblages in the sediments, and the record of
siliceous algal productivity is obtained from profiles of loosely bound silica. Aquatic
macrophyte abundance in 5 of 7 billabongs examined decreases markedly at
settlement, notwithstanding that taphonomic alteration of assemblages increases. The
pattern is most pronounced in large, deep billabongs, and absent from small
billabongs. The decline in macrophytes appears to have resulted in the demise of a
group of closely related Rak or Ephemeroporus species that are codominant before
settlement. Otherwise, the regional diversity of Cladocera has changed little with
settlement, and possibly even increased from the introduction of exotic species.
However, temporal trends in 7 species suggest they will be pushed towards regional
extinction in the future. Siliceous algal productivity appears to have decreased in 4 of 7
billabongs with settlement, although the patterns may be an artefact of increasing
sedimentation rates. The patterns are most pronounced in small billabongs, and due to
their timing an early land use activity is again implicated.
The historical data suggest that the aquatic macrophyte flora and associated fauna
declined due to an early land use activity related to farming. It is likely that the change in redox occurred due to the decline in macrophytes, which lowered organic matter
supply to the profundal zone. Furthermore, the persistence of depressed macrophyte
levels, and continuing trends of changing relative abundance of some cladoceran
species, suggest that the farming impacts are of the press variety, yet direct farming
activity on the floodplain may have decreased this century.
The macrophyte-free state may been maintained in large, deep billabongs, in spite of
the removal of the disturbance agent, because of the existence of alternative stable
states in the aquatic vegetation. Early farming may have caused the large, deep
billabongs to switch from natural macrophyte dominance to natural phytoplankton
dominance, as has been suggested to occur in shallow lakes in Europe. If so, it is quite
likely that the decline of macrophytes in large, deep billabongs is reversible by
temporarily lowering water levels in the spring time, and this would greatly benefit
billabongs and the greater floodplain ecosystem. Once macrophyte beds are reestablished
they should be stable unless further unnatural perturbations occur. If
properly designed, attempts to restore macrophytes in billabongs can be used to test
the hypothesis of alternative stable states in billabong vegetation, so that such attempts
offer an opportunity to meld management and science in one project.
This work demonstrates that even in ecosystems with high rates of turnover, events
with return times on the order of centuries can have significant impacts on the
ecosystem. Assessments of anthropogenic impacts to billabongs that do not include an
historical component are likely to provide underestimates of the full impacts. While
disturbance concepts appear to explain some of the patterns observed in the biota,
other traits of the ecosystem (e.g. alternative stable states in the vegetation) may be
required to explain the broad-scale patterns observed.
30
Ross, Andrew James. "Water connecting, people adapting : integrated surface water and groundwater management in the Murray-Darling Basin, Colorado and Idaho." Phd thesis, 2012. http://hdl.handle.net/1885/149682.
Full textAbstract:
Integrated water management helps adaption to variable rainfall by using more groundwater during dry years and more surface water during wet years. Integrated water management techniques including water banking, and aquifer storage and recovery are extensively practiced in other dry regions such as the western USA and Spain. Yet these techniques are not used in the Murray-Darling Basin. This thesis explores factors which have affected integrated water management in the Murray-Darling Basin, and in the states of Colorado and Idaho in the USA. The most important contribution of this research is that it sets out the advantages of integrated cyclical water management, and points to the opportunities for aquifer storage and recovery and water banking. Integrated surface water and groundwater storage is the missing link in Australia's otherwise comprehensive water reform. This thesis uses a narrative synthesis approach for analysing factors that have affected integrated water management. This approach relies on qualitative analysis of findings from existing studies and documentary evidence, supplemented and cross checked by interviews. It is proposed that integrated water management may be considered as a process taking place in a complex social and ecological system. Fourteen key variables that affect integrated water management were selected drawing on Ostrom's framework for the analysis of social ecological systems, relevant scientific literature and discussions with water managers and experts. The relationship between these variables and integrated water management were explored in two comparative case studies. The first case study enabled a broad assessment of factors that have affected integrated water management at a jurisdictional scale in the Murray-Darling Basin. The second case study enabled a more detailed exploration of the impact of water entitlements, operational rules and management organisation(s) on integrated water management in tributary catchments in New South Wales, Colorado and Idaho. The development of integrated surface water and groundwater management, especially in the Murray-Darling Basin has been constrained by the surface water centric development of water resources and institutions, gaps in knowledge about surface water and groundwater connectivity, the lack of a comprehensive, flexible and balanced system of water entitlements and rules, and implementation difficulties. Further development of integrated water management requires better knowledge and improved management capacity. Further research and development needs to be devoted to the integrated management of water stocks and storages - a missing link in Australian water reform. Further research is required to improve understanding about surface water - groundwater connectivity and to develop strategies for managing long-term impacts of groundwater use. Ongoing development of flexible systems of water entitlements and rules is needed to enable cyclical surface water and groundwater management. Finally the capacity for the implementation of integrated water management at local and regional scales needs to be improved together with collaboration between higher-level governments and local organisations and stakeholders. -- provided by Candidate.
31
Dwyer, Brian J. "Aspects of governance and public participation in remediation of the Murray-Darling Basin." Thesis, 2004. http://handle.uws.edu.au:8081/1959.7/776.
Full textAbstract:
This thesis addresses the question “What is the essence of the Murray Darling river system conundrum that is usually posed as an issue of environmental remediation?”- following perceptions of problems in catchment strategy formulation regarding project selection and public consultation. The question is initially seen as having four facets – governance, public, participation and remediation. An initial literature review indicated that previous examination of these topics seemed insufficiently radical or comprehensive for the enquiry’s purposes, seeming not to attribute full humanness to members of the public. A fieldwork program of quasi-anthropological nature was conducted. Interpretation of the fieldwork reports focuses primarily on the lack of attribution of full humanness to members of the public. Interpretive techniques including a phenomenological-style process was applied and found that the district houses a number of unrecognised people “nexors’ occupying linking or nexus roles who exercise personal skills and initiatives to underpin effective remediation outcomes. Towards the end of the fieldwork program, further literature indicated that the initial four-facet nature of the enquiry should be reformulated, to include the overall nature of western society as it appears in the district (in place of participation), to reconstitute the concept of remediation more radically. Governance as a topic is broader than the ways in which it appears in the examined district, and suitable hybridizing of competing world view concepts remains unresolved in this thesis
32
Jiang, Qiang. "Three essays on water modelling and management in the Murray-Darling Basin, Australia." Phd thesis, 2011. http://hdl.handle.net/1885/151262.
Full textAbstract:
The primary contributions of this thesis are the economic studies of proposed water use reductions and climate change, and the development of an integrated hydro-economic model for the Murray-Darling Basin, Australia. This water model not only simulates the land and water use in the Basin, but also optimises these uses for certain targets such as environmental flows. More importantly, this model can be applied to evaluate policy options for the Basin, such as water buybacks, and provide estimates of the possible impacts of climate change.
The thesis consists of three main essays focusing on issues in water modelling and management in the Basin. The first essay describes the development of a water model. This model is applied to estimate the impacts of water use reductions in the second essay; and climate change in the third essay. Other issues related to the Basin's water management, such as a review of existing water modelling, the background of the Basin, water trading, possible policy implementations and future research are also discussed.
The first essay (Chapter 4) describes the construction of the Integrated Irrigated Water Model (IIA WM) including the structure of llA WM and the data sources. Using the latest hydrological data and revised catchment boundaries, llA WM can simulate and optimise land and water use in the Basin. To address the criticism that existing models have failed to consider water trading barriers, the physical constraints on water trading have been incorporated in llA WM. The model can also evaluate various water policies and estimate the impacts of physical condition changes.
The second essay (Chapter 5) evaluates the impacts of proposed water use reductions by the Australian government. To balance the use of water between irrigated industries and environmental purposes, the Australian government draft plan released October 2010 proposed to reduce the volume of used water in the Basin from 3,000 to 4,000 GL/year. Simulations from IIA WM indicate that the impacts from proposed water use reductions will be modest, although there may be substantial impacts in particular locations.
The third essay (Chapter 6) investigates the impacts of climate change in the Basin. A full range of climate change scenarios from modest to severe have been applied using IIA WM. This thesis finds that with water trading, profit reductions are substantially smaller than the water use reductions.
33
Ho, Michelle. "A paleoclimate-informed examination of flood and drought epochs in the Murray-Darling Basin." Thesis, 2014. http://hdl.handle.net/1959.13/1048522.
Full textAbstract:
Research Doctorate - Doctor of Philosophy (PhD)<br>The Murray-Darling Basin (MDB) is Australia’s largest water catchment and the nation’s reputed ‘food bowl’. Climate, and consequently water availability, in the region is highly variable both temporally and spatially, as evident in the regular occurrence of floods and persistent droughts and the regionally distinctive impacts of such events. A key limitation to accurately quantifying flood and drought risks in the region is the relatively short instrumental records (approximately 100 years at best) of rainfall and stream flow. Furthermore, research over the past few decades has revealed that flood and drought risks across the MDB are modulated by a number of different large-scale climate drivers (e.g. El Niño/Southern Oscillation, Southern Annular Mode, Indian Ocean Dipole and Interdecadal Pacific Oscillation) on seasonal to multi-decadal timescales. These climate mechanisms influence the MDB hydroclimate both individually and in combination. Current assessments of flood and drought risk are based on relatively short instrumental records and are therefore inadequate for properly evaluating either multidecadal variability or the influence of numerous largescale climate drivers on MDB hydroclimatic variability. This thesis aims to improve understanding of long-term flood and drought risk in the MDB through the use of paleoclimate records of both large-scale ocean-atmospheric processes and continental Australian rainfall. The use of paleoclimate data will enable improved insight into pre-instrumental climate variability. The efficacy of using paleoclimate proxy records of large-scale climate drivers (e.g. the El Niño Southern Oscillation, the Indian Ocean Dipole, the Southern Annular Mode, the Interdecadal Pacific Oscillation and the Pacific Decadal Oscillation) to reconstruct MDB rainfall was examined. In order to reconstruct MDB rainfall using these relationships, both linear and non-linear relationships between MDB rainfall and different climate drivers and combinations of drivers were quantified. Importantly, it was found that the MDB rainfall response was markedly different when climate drivers were considered in combination compared to the response to a single climate driver. Currently, numerous multi-centennial paleoclimate records exist for the El Niño Southern Oscillation and the Pacific Decadal Oscillation. However, paleoclimate reconstructions of other climate drivers are less developed, limiting the feasibility of paleoclimate driver based reconstruction methods. Nevertheless, this work has highlighted significant potential for using paleoclimate proxy records of large-scale climate drivers to reconstruct MDB rainfall variability should multi-centennial records of Indian and Southern Ocean variability for key seasons, as well as the Pacific Ocean Basin-wide Interdecadal Pacific Oscillation, become available in the future. In addition to assessing the possibility of reconstructing MDB rainfall using paleoclimate proxy records of large-scale climate drivers, another approach was explored. This second approach attempted to utilise paleoclimate proxy records of rainfall that exist in Australia through the investigation of relationships between rainfall in the MDB and Australian rainfall outside the MDB. At present, only three continuous, high-resolution paleoclimate rainfall records exist in Australia, none of which are in the MDB. While in situ paleoclimate proxies would be ideal, there are currently no existing proxies in the MDB that provide continuous, high-resolution records of hydroclimatic variability. In addition, paleoclimate archives capable of sensing and recording rainfall variability at high resolutions are unlikely to be found in the MDB. Given the technical difficulty and costs involved in obtaining paleoclimate records, it is prudent to determine regions where the future assembly of these records would be of most use to reconstructing MDB rainfall (i.e. regions that would most accurately reconstruct MDB rainfall variability). This was achieved using an optimal interpolation procedure. Locations around Australia were sequentially selected to optimise the degree of MDB rainfall variability that could be resolved. The locations were then compared with sites that could potentially yield continuous, high-resolution, rainfall-sensitive paleoclimate archives, thereby providing an indication of where future paleoclimate research efforts could be concentrated to maximise the accuracy of MDB rainfall reconstructions. In order to demonstrate the utility of the existing Australian paleoclimate rainfall proxy records to remotely reconstruct MDB rainfall, reconstructions of rainfalls in four casestudy sub-catchments were made using the three available records. Four different reconstruction models were calibrated. The best model was able to resolve between 35% and 61% of rainfall variability in the four case-study sub-catchments when calibrated using instrumental data from the three proxy rainfall sites. The modelled results were then compared to rainfall in the four case-study MDB sub-catchments modelled using rainfall from the first three locations selected from the optimal interpolation procedure (i.e. the ideal locations). Rainfall from the first three optimised locations was able to resolve between 62% and 82% of MDB rainfall variability. This demonstrates the importance of obtaining additional paleoclimate data in optimal locations to more accurately reconstruct MDB rainfall. A key outcome of this work was the reconstructions of rainfall in four case-study MDB sub-catchments using existing high-resolution paleoclimate rainfall records around Australia. The reconstruction enabled an assessment of rainfall variability from 1685- 1981 using all three paleoclimate proxies and an extended reconstruction from 749 BCE to 2001 CE using the Wombeyan Cave record. The reconstructions showed that the risks of flood and drought have been higher prior to the instrumental records in both magnitude and persistence. A qualitative comparison was also made between the reconstruction of rainfall in the upper Murray catchment and previous paleoclimate reconstructions of hydroclimatic variability in the MDB. This work demonstrated that the realisation of a high-resolution paleoclimate rainfall network around Australia as determined in the optimal interpolation, would enable an increased degree of variance to be captured in reconstructions of MDB rainfall. In addition, it was revealed that extending the current paleoclimate records of Pacific, Indian and Southern Ocean variability spanning the Common Era will also enable MDB rainfall variability to be reconstructed. Reconstructions of MDB rainfall variability using different networks of paleoclimate data are expected to enable more accurate estimates of long-term flood and drought risks in the MDB. This would then provide a realistic assessment of the baseline risks, thus enabling the adoption of robust water resource management schemes capable of responding to the degree of natural variability identified from paleoclimate-based reconstructions. Such information will also enable future climate scenarios to be adequately constrained, validated and assessed using a multi-centennial or multi-millennial perspective of past hydroclimatic variability.
34
Horner, Kyle. "New environmental tracer methods for quantifying solute sources in semi-arid alluvial aquifers." Phd thesis, 2013. http://hdl.handle.net/1885/156182.
Full textAbstract:
Alluvial aquifer systems produce up to 60% of groundwater extracted in Australia. Identifying solute sources to these fresh water reservoirs is vital for their long-term sustainable management. In this thesis, new environmental tracer techniques are presented for quantifying the contributions of various processes to groundwater solute loads in semi-arid alluvial aquifers, extending the range of methods available for characterising solute sources in similar settings around the world. The methods are demonstrated in a surface water and groundwater study of the Lower Murrumbidgee Groundwater Management Area of south-east Australia's Murray Basin. Equations derived using Cl/Br ratios are used to quantify the input of chloride salts to dissolved chloride in waters subjected to evaporation and transpiration. The equations are applied to assess the contributions of halite to groundwater salinity in the Lower Murrumbidgee, where Cl/Br ratios are heterogeneous. Low, uniform Cl/Br ratios suggest negligible halite dissolution in the catchment's east while a systematic increase in Cl/Br ratios suggests up to 50% of dissolved chloride in the west could be from halite. Numerical simulations of the basin-scale "cyclic salt" conceptual groundwater salinisation model are used to quantify meteoric inputs to groundwater and to identify where additional processes not in the conceptual model contribute to aquifer salinity. Groundwater quantity in the study area is shown to depend on the leakage rate of the Murrumbidgee River to regional aquifers, but groundwater quality depends on the rate of cyclic salt input from the vadose zone. Solute distribution in irrigated areas deviates from the regional trend. Results indicate irrigation return flows have mobilised solutes in the unsaturated zone, but in-situ dissolution of soluble minerals does not significantly contribute to aquifer salinity. Stable silicon isotopes are used to examine spatial and temporal variations in silicate weathering in the Lower Murrumbidgee, where silica accounts for up to 30% of total dissolved solids in low-salinity groundwaters. A new conceptual model of silicon isotope fractionation during silicate weathering is presented and an existing mathematical model of isotope fractionation is adapted to calculate silicon isotope composition in solution. Fractionation is shown to be pathway-dependent, greatest in weathering processes that sequester high proportions of silica in secondary phases. Silicon isotope data from the Lower Murrumbidgee indicates that weathering intensity in the catchment may have increased over the last 20 000 years, and surface water 30Si values indicate a similar increase in the headwater catchments during the same period.
35
Thampapillai, Vinoli. "Environmental Flows in the Murray-Darling Basin : Market Based Governance Public Institutional and Legal Reform." Phd thesis, 2014. http://hdl.handle.net/1885/156074.
Full textAbstract:
The Murray Darling Basin (MDB) is a major irrigated agricultural region known as the food bowl of Australia. Over-allocation of water rights to irrigation in the MDB has mimicked a tragedy of the commons and has led to the degradation of the ecosystem of rivers in the basin. Competition between environment and agriculture is at the heart of the problem. As water in the river systems is semicommon, where private and common rights coexist and interact due to the fluid nature of the resource, employing an exclusion strategy is difficult. Hence governance is central to the management of the river system to ensure ecosystem resilience. The key governance solutions to this problem employed by the Commonwealth government are the use of the water market to reconfigure water from irrigation to the environment, and use of the Federal Water Act 2007 to harmonize water planning across the transboundary river system which extends over four states and one territory. There exists ongoing disappointment in current market based, legal and institutional policy in the Murray Darling Basin articulated by irrigators and State governments. Significant resistance to the government water buyback program has been expressed by irrigators and the upstream state governments. The governments of Queensland and New South Wales waited until February 2014 to sign the agreement for implementation of the MDB Plan which entered into effect in November 2012. Agreement was secured after the Federal government agreed to legislate to cap buybacks at 1500 GL. As of February 2014, 1200 GL (long term average) of the 2750 GL required for the environment has been acquired by government due to resistance by upstream states and irrigators. There is an absence of comprehensive treatment of the water governance problem. Therefore this research examines the limitations of the water market, water law and public institutions to address the identified problem in the MDB. A combination international comparative water law, a qualitative survey of 41 irrigators, conducted across four jurisdictions of the MDB, documentary analysis is employed in the research, viewed through the lens of New Institutional Economics. This dissertation is concerned with two central research questions pertaining to water governance structures for addressing over-allocation and the delivery of environmental flows to build ecosystem resilience in the Murray Darling river system. The research questions are articulated as follows: (i) What are the limits of market based water governance expressed as water buybacks, as a means of reconfiguring private water rights toward environmental flows in the Murray Darling river system for building ecosystem resilience? (ii) Which public institutional and legal reforms are necessary to resolve the conflict between environmental and socio-economic uses of the Murray Darling river system in order to maintain ecosystem resilience? The analysis of the research highlights three central limits to the use of water markets for the reconfiguration and efficient management of environmental flows by the Commonwealth Enviromnental Holder. Through examination of bounded rationality articulated in New Institutional Economics Theory, three interrelated limits were identified namely, the endowment effect, free rider effect, and lack of a transition economy to overcome the contraction of the rural economy caused by reduction of irrigation activity. This dissertation is one of the few to demonstrate the presence of an endowment effect in the real world setting, outside an experimental setting. The endowment effect refers to the initial assignment of property, the effect of which has been shown to place a limitation on trading activity in numerous contexts. This occurs because the willingness to accept (WT A) payment to relinquish property owned, far exceeds the willingness to pay (WTP) to acquire the same property. The endowment effect tied to the free rider effect can be addressed by a sustainable rural economic transition strategy. Lack of viable, alternate economic development has proven to be a problem in rural and regional Australia. This dissertation highlights the importance of investment in training, research and innovation in Information Communication Technology (ICT) in the MDB as a transition strategy attached to water policy. New Institutional Economics theory informs of the importance of institutional linkages for the achievement of transition economy goals between the MDBA and relevant government departments, including Treasury, Finance, Communications, Education, Employment and Training, and AUSTRADE. These institutional linkages have the potential to convert the economy dependent on agriculture to a knowledge economy over a period of two decades. This transition has the potential to reduce the level of youth migration from the rural sector to the urban sector, increasing the possibility of service sector expansion. At every major stage of water reform in the MDB to reduce over-extraction, from the 1994 cap and trade system, to the 2004 National Water Initiative to the Water Act 2007, a sustainable rural economic transition strategy has been repeatedly missed by successive governments. However State governments post-2011 have very belatedly commenced raising the matter of structural adjustment repeatedly in negotiations with the Federal government following vocal protests by irrigators. This dissertation also highlights limitations of water law and public institutions which include the absence of effective conflict resolution rules, mistrust in government management of water, mistrust in government institutional capacity, inadequate information flow and lack of clarity over property rights and compensation rules. Reform proposals therefore concern inclusion of conflict resolution provisions at the daily operational level and the Federal and State level. Daily operation rules adapted for the MDB focus on ongoing cooperation between heterogeneous users at the regional level to minimize conflict. At the Federal and State level the reform model proposes modification of the "no significant harm rule" articulated in international law, to include cost-benefit analysis rules and compensation rules. This dissertation proposes inclusion of the substantially modified "no-significant harm" rule as an amendment to the Water Act 2007. The aim of the no significant harm rule is to ensure all parties consider the impact of their actions upon other stakeholders and to promote respectful dialogue between parties. The model proposed sought to address key concerns pertaining to institutional bias, valuation methods and mechanisms to address harm to the rural economy. Inclusion of the modified "no significant harm rule" holds the potential to improve cooperative negotiations between State and Federal governments to optimize environmental, social and economic outcomes, as required by Article 3 of the Water Act 2007.
36
Shahjahan, Mosharefa. "Integrated river basin management for the Ganges: lessons from the Murray-Darling and Mekong River Basins (a Bangladesh perspective)." 2008. http://hdl.handle.net/2440/49983.
Full textAbstract:
This thesis examines the applicability of the Murray-Darling Basin (MDB) model of Integrated River Basin Management to the Ganges Basin by utilising the lessons from the Mekong experience of adopting the MDB model. The Ganges is one of the major rivers in the world and the sharing of its water has long been an issue of dispute between the riparian countries. Fragmented and uncoordinated upstream management of the Ganges has caused serious ecological and economic loss in the downstream environment posing a threat to future sustainability of river resources. Cooperation among the riparian countries of the Ganges in order to embrace an integrated and basin-wide management approach is rapidly becoming more important. Integrated River Basin Management (IRBM) is a concept widely advocated in different forums for managing the river basins of the world and is adopted in many transboundary river basins. The Australian example of managing the Murray-Darling Basin is considered as a model in the field. The Murray-Darling Basin Commission is well known internationally as a good example of a multi-jurisdictional water management institution. Similar river basin institutions are also evolving in other regions such as the Mekong River Commission for the management of the Mekong River in South-East Asia. The countries sharing the Ganges could learn lessons from the Murray-Darling and Mekong experiences and adopt a basin-wide approach for the better management of the Ganges. However, the policy transfer from a developed country to a developing country context is a challenging process. The highly pertinent contextual differences in social, economic, political, environmental and hydrological settings of the three cases need to be carefully addressed. The research critically examines these factors in the Murray-Darling, Mekong and the Ganges contexts, identifies the similarities and differences between them and attempts to understand the influence/s of these in the policy transfer or policy development process. This research adopted multiple-case studies involving both qualitative and quantitative methods. The cases of the Murray-Darling and Mekong were studied to understand the process and to utilise the lessons learned for the institutional development towards integrated and basin-wide approach for the Ganges. The study analyses the interview results from the experts in the relevant fields to get an insight of different issues and also to collect their opinions. The responses from the stakeholder interviews in Bangladesh were analysed to understand their perspective in this regard. The thesis concludes that adoption of the Murray-Darling Basin model of integrated management needs modification in the Ganges context and recommends a specific institutional structure for the basin-wide management of the Ganges. The thesis contributes to an area of knowledge in recent times by providing a greater understanding of the Integrated River Basin Management in a multi-jurisdictional context. It critically examines the issues in policy transfer from a developed to a developing country focussing on a little studied but significant international river basin, the Ganges. It is hoped that this thesis will contribute towards better policy options for the sustainable management of the international river system.<br>http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1321536<br>Thesis (Ph.D.) - University of Adelaide, School of Social Sciences, 2008
37
Shahjahan, Mosharefa. "Integrated river basin management for the Ganges: lessons from the Murray-Darling and Mekong River Basins (a Bangladesh perspective)." Thesis, 2008. http://hdl.handle.net/2440/49983.
Full textAbstract:
This thesis examines the applicability of the Murray-Darling Basin (MDB) model of
Integrated River Basin Management to the Ganges Basin by utilising the lessons from the
Mekong experience of adopting the MDB model. The Ganges is one of the major rivers in
the world and the sharing of its water has long been an issue of dispute between the
riparian countries. Fragmented and uncoordinated upstream management of the Ganges
has caused serious ecological and economic loss in the downstream environment posing a
threat to future sustainability of river resources. Cooperation among the riparian countries
of the Ganges in order to embrace an integrated and basin-wide management approach is
rapidly becoming more important.
Integrated River Basin Management (IRBM) is a concept widely advocated in different
forums for managing the river basins of the world and is adopted in many transboundary
river basins. The Australian example of managing the Murray-Darling Basin is considered
as a model in the field. The Murray-Darling Basin Commission is well known
internationally as a good example of a multi-jurisdictional water management institution.
Similar river basin institutions are also evolving in other regions such as the Mekong River
Commission for the management of the Mekong River in South-East Asia. The countries
sharing the Ganges could learn lessons from the Murray-Darling and Mekong experiences
and adopt a basin-wide approach for the better management of the Ganges. However, the
policy transfer from a developed country to a developing country context is a challenging
process. The highly pertinent contextual differences in social, economic, political,
environmental and hydrological settings of the three cases need to be carefully addressed.
The research critically examines these factors in the Murray-Darling, Mekong and the
Ganges contexts, identifies the similarities and differences between them and attempts to
understand the influence/s of these in the policy transfer or policy development process.
This research adopted multiple-case studies involving both qualitative and quantitative
methods. The cases of the Murray-Darling and Mekong were studied to understand the
process and to utilise the lessons learned for the institutional development towards
integrated and basin-wide approach for the Ganges. The study analyses the interview
results from the experts in the relevant fields to get an insight of different issues and also to
collect their opinions. The responses from the stakeholder interviews in Bangladesh were analysed to understand their perspective in this regard. The thesis concludes that adoption
of the Murray-Darling Basin model of integrated management needs modification in the
Ganges context and recommends a specific institutional structure for the basin-wide
management of the Ganges.
The thesis contributes to an area of knowledge in recent times by providing a greater
understanding of the Integrated River Basin Management in a multi-jurisdictional context.
It critically examines the issues in policy transfer from a developed to a developing country
focussing on a little studied but significant international river basin, the Ganges. It is hoped
that this thesis will contribute towards better policy options for the sustainable
management of the international river system.<br>Thesis (Ph.D.) - University of Adelaide, School of Social Sciences, 2008
38
Haensch, Juliane. "Examining the importance of spatial influences on irrigators’ water trading behaviour in the Southern Murray-Darling Basin." Thesis, 2017. http://hdl.handle.net/2440/107398.
Full textAbstract:
Water trading is increasingly becoming an important farm management tool for irrigators to manage changing environmental conditions. Studies have found that water trading increases farmers’ flexibility in water use and moves water from lower value (or less efficient) uses to higher value (or more efficient) uses. Many countries that regularly suffer periods of droughts and have over-allocated water resources face a growing challenge to allocate water to competing water uses. Some of these countries have introduced water markets as a response to help enable an efficient allocation of a scarce resource. This is especially so in Australia’s Murray-Darling Basin (MDB), which has had water markets in place for decades. The southern MDB is one of the most active water trading region worldwide, and hence, provides an ideal case study for examining water trading behaviour. The MDB faced the Millennium Drought in the 2000s which caused intensive distress for all alike: irrigators, tourists, rural communities and especially the environment. During the midst of this drought the Federal government introduced a water buyback program that purchased water entitlements from willing irrigators to return to environmental use. To date, a number of studies have investigated irrigators’ determinants to trade water. This literature has primarily focused on farmers’ socio-economic and farm specific characteristics. But there is evidence that water trading is also affected by spatial factors, especially water entitlement trading. Thus, this thesis explores the relevance of spatial influences on irrigators’ water trade decision-making. Traditional economic models of water trading behaviour are expanded with several spatially explicit variables, such as biophysical and distance factors. The influence of neighbours’ water trading decision-making (‘neighbourhood effect’) is also tested, as anecdotal evidence shows that in the past irrigators experienced considerable social pressure if they sold or were willing to sell water entitlements. Furthermore, this thesis also examines the influence of spatial factors on irrigators’ price choices for selling and buying water entitlements. The results show that a number of spatial influences significantly affect water trading behaviour, especially water entitlement selling behaviour. Irrigators located in poorer resource areas (e.g. regarding soil degradation), in more rural areas and regions that suffer a socioeconomic decline (e.g. population decline) are more likely to sell water entitlements. There is evidence of a substitution effect between surface-water and groundwater (where viable groundwater resources exist). Irrigators in more rural areas tend to sell larger volumes of water entitlements and buy larger volumes of water allocations. Furthermore, a positive neighbourhood effect is confirmed, where irrigators’ decisions to sell water entitlements was influenced by their neighbours. Over time, it became more socially acceptable to sell water entitlements. Finally, spatial influences also affect irrigators’ valuation of their water, which is reflected in their price choices for water entitlement selling. Overall, the results of this thesis support some existing policy measures and programs (e.g. salinity impact zones) and lead to several other policy implications. One such conclusion is the need to focus policy on water entitlement buybacks rather than on water irrigation infrastructure. This thesis concludes that current and future polices (e.g. related to the water buyback) could be more spatially targeted while also considering the externalities and wider irrigator behaviour in policy development. Spatially refined policies have the potential to improve the outcome of water markets (and related environmental programs) and alleviate the pressure on socio-economic and environmental systems.<br>Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, Centre for Global Food and Resources, 2017.
39
Wedderburn, Scotte Douglas. "Population fragmentation in the Murray Hardyhead Craterocephalus fluviatilis McCulloch, 1912 (Teleostei: Atherinidae) : ecology, genetics and osmoregulation." 2009. http://hdl.handle.net/2440/54232.
Full textAbstract:
Population fragmentation is a common symptom of the decline of species, including freshwater fishes. It occurs naturally, but has also proliferated in response to human interventions that increase the prevalence and intensity of isolating barriers and events. In regulated rivers, for example, fish are affected by the loss of connectivity between habitats that is associated with hydrological changes. The process has evolutionary consequences by limiting gene flow, reducing genetic diversity and rendering the isolates vulnerable to local environmental changes. Comparative studies of related species may help to elucidate the causes and consequences of fragmentation. For example, they may identify habitat features that influence the spatial separation of congeneric species. An opportunity for such a study arises with small fishes (Atherinidae) in the intensively-regulated River Murray, southeastern Australia. Whereas the unspecked hardyhead Craterocephalus stercusmuscarum fulvus is widespread and abundant, the Murray hardyhead C. fluviatilis has a patchy distribution and is listed as 'endangered‘ by the International Union for Conservation of Nature and 'vulnerable‘ under the Australian Environment Protection and Biodiversity Conservation Act 1999. These two species rarely cohabit, implying that they could be separated by particular habitat characteristics. In the past, several species of Craterocephalus, including C. fluviatilis and the Darling River hardyhead C. amniculus, have been regarded as C. eyresii sensu lato. The taxonomic separation of C. s. fulvus has been confirmed, but some doubt remains about the relationship of C. fluviatilis and C. amniculus. This issue needs resolution to ensure that appropriate targets are set for conservation. This study is a comparative investigation of the aforementioned species. It was designed (1) to identify the habitat characteristics that influence the distribution and abundance of C. fluviatilis and, given that salinity emerged as a key factor, (2) to explore the biological implications of salinity through a comparative study of osmoregulation in C. fluviatilis and C. s. fulvus, (3) to determine whether the osmoregulatory responses of population isolates of C. fluviatilis differ at varying salinities, and (4) to evaluate the genetic population structure of C. fluviatilis, confirm its taxonomic separation from C. amniculus and identify genetic 'management units‘ for conservation. Field sampling showed that C. fluviatilis is confined mainly to saline waters (0.4-20‰), whereas C. s. fulvus is absent from salinities >7‰. Comparisons were made of osmoregulation in these two taxa over a salinity range of 0.03-85‰, with additional reference to the small-mouth hardyhead Atherinosoma microstoma, a related estuarine species that tolerates salinities >94‰. The three species all are euryhaline, although the osmoregulatory ability of C. s. fulvus falters above about 35‰ salinity. C. fluviatilis is a better osmoregulator than A. microstoma at salinities <1‰, but both species tolerate hypersaline conditions (85‰). Osmoregulation was compared in C. fluviatilis from two isolated populations in different salinity regimes (Wyngate: 0.4-1.5‰, Disher Creek: c. 1.0-45‰) to determine whether they show related phenotypic differences. Fish from both populations remained healthy at salinities from 5-65‰. The Disher Creek population maintained a significantly lower blood osmotic concentration than the Wyngate population at salinities ≤1‰, suggesting that there is a physiological difference between them. The genetic population structure of C. fluviatilis and its taxonomic distinction from C. amniculus were investigated using complementary allozyme and mtDNA markers. This confirmed that C. fluviatilis is genetically distinct from its sister taxon, C. amniculus. It also identified several genetically-defined 'management units‘ as a framework for future conservation. Further, it revealed that C. fluviatilis in habitats downstream of Lock 1 on the Murray (274 km from the river mouth) displays a genetic signature indicating introgression with C. amniculus. Clearly, these findings have implications for the conservation of C. fluviatilis. For example, isolates can be prioritised for protection, and re-introduction programs can be modified accordingly. The findings may be applied to other freshwater fish, especially populations of closely-related species subject to salinisation or other stressors, and they may also contribute toward understanding of the factors and processes underlying rarity and fragmentation. It is clear that salinity can be a significant factor in population fragmentation, and that closelyrelated species with similar ranges may be segregated by differences in osmoregulatory ability.<br>http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1363300<br>Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2009
40
McCarthy, Michael G. (Michael George). "Effect of timing of water deficit on fruit development and composition of Vitis vinifera cv. Shiraz." 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phm1233.pdf.
Full textAbstract:
Includes bibliographies. This thesis describes an irrigation experiment established on Vitis vinifera cv. Shiraz in a mature vineyard in the Australian Murray-Darling basin. It concentrates on the relationship between the timing of the water deficit and the depth of irrigation applied and the difference in berry weight between different irrigation treatments. The study includes a polynomial equation which describes the relation between growing degree days and °Brix. A two phase linear model is used to describe the change in red-free glycosyl-glucose (G-G).
41
Connell, Daniel. "The Chariot Wheels of the Commonwealth." Phd thesis, 2005. http://hdl.handle.net/1885/49407.
Full textAbstract:
This thesis examines the role of inter-judisdictional institutions in the Murray-Darling Basin and discusses the potential impact of the National Water Initiative approved by the Council of Australian Governments in June 2004. Over the last century there have been two periods during which decision makers attempted to craft or re-craft interjurisdictional water management arrangements to suit the priorities of their times. This thesis suggests that the early twenty-first century shuold be another, Central is the argument that despite attempts to introduce a form of coordinated basin-wide management in the early twentieth century and in the 1980s, the record since then has been dominated by efforts to maximise state autonomy at significant and growing environmental cost to the region as a whole. The issues involved will be examined in the context of the Australian federal system and a discussion about the nature of the changes needed to implement more environmentally sustainable management. ...
42
Verdon, Danielle Cherie. "Pacific and Indian Ocean climate variability: implications for water resource management in eastern Australia." Thesis, 2007. http://hdl.handle.net/1959.13/1402983.
Full textAbstract:
Research Doctorate - Doctor of Philosophy (PhD)<br>The impacts of multi-temporal scale climate variability occurring over the Pacific and Indian Oceans on the rainfall and runoff regimes of eastern Australia are explored in this thesis. Three modes of natural climate variability are studied, the El Niño/Southern Oscillation (ENSO), the Interdecadal Pacific Oscillation (IPO) and the Indian Ocean Dipole (IOD). An analysis of historical rainfall and streamflow data for Queensland (QLD), New South Wales (NSW) and Victoria (VIC) reveals strong relationships between indices of ENSO and IPO variability and seasonal rainfall and streamflow totals in the spring and summer months. In addition, it is shown that a strong connection exists between a number of Indian Ocean SST indices and winter rainfall in eastern Australia, offering an improved understanding of year-round seasonal climates. A climate impact assessment is carried out for a regulated irrigation and domestic water supply system located in NSW (the Lachlan River Valley) to determine the main climatic drivers in the region. It is shown that ENSO, the IPO and the IOD have a strong impact on rainfall, evaporation and inflows, while storage volumes, water allocations and sustainable crop areas are also related to the state of ENSO and the IPO. The research presented in this thesis highlights the importance of understanding the role that natural climate variability plays in influencing the climate, water resources and agriculture in eastern Australia. A simple stochastic framework for use in long term drought risk assessment is developed that specially incorporates multi-decadal persistence of rainfall, brought about by changes in the IPO. The drought risk framework is applied to water resource assessment in the Lachlan River Valley, providing greater insight into the frequency, magnitude and duration of hydrological droughts than present approximations that use the limited instrumental record alone. Importantly, the results presented in this thesis highlight the fact that water resource management in eastern Australia must be developed to cope with the full range of natural climate variability, irrespective of future impacts of anthropogenic climate change, to aid in drought proofing our climate sensitive infrastructure.
43
Creeper, Nathan Leonard. "Inland acid sulfate soils in the floodplain wetlands of the Murray- Darling Basin: regional occurrence using rapid methods and the impacts of reflooding on water quality." Thesis, 2015. http://hdl.handle.net/2440/119793.
Full textAbstract:
A full appreciation of the extent and significance of acid sulfate soils (ASS) in Australia's inland environments has only recently been realised, in contrast to ASS in Australia’s modern-day coastal zones, which have been well studied over the last four decades. Investigations into the inland ASS systems of the Murray-Darling Basin (MDB), Australia's largest river system, did not occur with any intensity prior to 2006. A number of key knowledge gaps exist concerning the occurrence, properties and behaviour of inland ASS systems in the MDB. These knowledge gaps, combined with the ecological and economic significance of the MDB, and the potential for environmental and infrastructure degradation through ASS acidification, provided the incentive for this research project. The main objective was to advance the understanding of inland ASS in the MDB. This was achieved by answering two key research questions: What is the prevalence and distribution of ASS with hypersulfidic and sulfuric materials in the floodplain wetlands of the MDB? What are the dominant geochemical pathways taken following freshwater reflooding of inland ASS containing sulfuric materials and the timescales of impact? The first research question was answered through a regional assessment of ASS in the MDB and represents the most extensive estimate of the basin-wide occurrence of inland ASS in the floodplain wetlands of the MDB thus far. As part of a government funded initiative, regional environmental officers collected approximately 7200 wetland soil samples, which were then submitted for soil incubation tests. The large number of samples requiring analysis, and the need for the rapid and robust classification of hypersulfidic materials led to the development of a simplified incubation method (see Chapter 2). This method was found to offer significant improvements over existing incubation methods. Firstly, the use of chip-trays as incubation vessels was found to offer many advantages in terms of transport, storage and analysis of soil samples compared with soil-slabs. Secondly, the conditional extension of the incubation period resulted in the accurate classification of slowly acidifying hypersulfidic materials whist maintaining a minimal test length. Following its development, the simplified incubation method was used to assess the acidification potential of ca. 2500 profiles in over 1000 wetlands located throughout the MDB (see Chapter 3). The results of pH measurements made before and following soil incubation were used to estimate the prevalence and distribution of sulfuric and hypersulfidic ASS materials across the MDB. A total of 238 floodplain wetlands, representing 23% of the total wetlands assessed, were found to contain soils that severely acidified (pH < 4) when oxidised. The number of these soils, the majority of which are likely to be hypersulfidic ASS materials, indicates that inland ASS are prevalent in the floodplain wetlands of the MDB. As a result, the potential existence of inland ASS should be a key consideration for wetland management plans in any floodplain wetland located in the MDB. The distribution of ASS materials in the MDB was investigated by dividing it into 13 geographical regions, whose boundaries roughly followed hydrological catchment boundaries. The distribution of acidification hazard was non-uniform throughout the MDB. The geographical regions with the greatest acidification hazard were in the southern MDB, downstream of the Murray-Darling confluence, and in catchments on the southern side of the Murray River channel in Victoria. The non-uniform distribution of ASS throughout the MDB has implications for the successful management of inland ASS in the MDB, whereby regions presenting the greatest acidification should receive much greater attention. Overall, the development of the simplified incubation method and the extensive broad-scale assessment of ASS in the MDB provided policy makers with a valuable screening tool, helping them to identify priority wetlands and regions that required more detailed IASS investigations. The second research question was answered through two focused field studies, which applied in situ sampling and monitoring techniques to investigate the geochemical behaviour of severely acidified inland ASS materials following reflooding by freshwater. The reflooding of severely acidified inland ASS by freshwater has been suggested as a viable remediation method. However, this hypothesis is based on observations made in coastal ASS systems following reflooding by sea water and had not yet been extensively documented in freshwater systems at the commencement of this research project. In the first study, equilibrium dialysis membrane samplers were used to investigate in situ changes to soil acidity and abundance of metals and metalloids following the first 24 months of restored subaqueous conditions (see Chapter 4) In the second study, mesocosms were installed in situ to simulate reflooding and the key geochemical pathways were documented through continuous in situ redox monitoring and the use of in situ soil solution samplers (see Chapter 5). In both studies, the strongly buffered low pH conditions of the oxidised sulfuric materials and the limited supply of external alkalinity in freshwater systems meant that soil acidity persisted for more than 24 months following reflooding. The persisting low pH conditions, along with insufficiently reducing redox conditions, and competitive exclusion by iron(III)-reducing bacteria were suspected to inhibit sulfate reduction. Following the eventual removal of the above limitations it is hypothesised that the lack of readily available soil organic carbon will further inhibit sulfate reduction. Under continued absence of net in situ alkalinity production, via the formation of reduced inorganic iron and sulfur species, observed trajectories indicate that neutralisation of soil acidity may take several years. Small increases in soil pH confined to within 10 cm of the soil-water interface were observed after 24 months of subaqueous conditions. Substantial decreases in the concentrations of some metals and metalloids were observed to coincide with the small increases in soil pH, most likely owing to lower solubility and sorption as a consequence of the increase in pH. In the acidic porewaters, aluminium activity was consistent with a control by a solid phase aluminium species with stoichiometry Al:OH:SO4 (e.g. jurbanite). In the same acidic porewaters, iron and sulfate activity were regulated by the dissolution of natrojarosite. Following the establishment of reducing conditions, the reductive dissolution of accumulated natrojarosite and schwertmannite phases was responsible for large increases in total dissolved iron. The differing physical properties and chemical characteristics, such as stored acidity and contaminant concentrations, of dominantly clayey soils and dominantly sandy soils, led to contrasting impacts on the transport of solutes following reflooding (diffusive versus advective flow, respectively) and timescales of recovery. A number of key geochemical processes influencing the porewater concentrations of acidity, iron, aluminium, and metals and metalloids following reflooding by freshwater were observed in these severely acidified inland ASS systems. These physical and geochemical processes were summarised in two conceptual hydrogeochemical process models, which were used to distil complex information and convey it in a format readily understandable to a non-ASS specialist audience.<br>Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Biological Sciences, 2015.
44
Harland, A. N. "Tracing local hydrology and water source use of Eucalyptus largiflorens on the Calperum Floodplain using strontium, oxygen and deuterium isotopes." Thesis, 2018. http://hdl.handle.net/2440/130626.
Full textAbstract:
This item is only available electronically.<br>Black Box trees (Eucalyptus largiflorens) across the Murray-Darling Basin are in critical condition due to high groundwater salinity and infrequent natural flooding. Geochemical tracers such as radiogenic strontium (87Sr/86Sr), oxygen-18 (𝛿𝛿18O) and deuterium (𝛿𝛿D) are considered useful in the understanding of catchment hydrology and plant water use, and in this study, 87Sr/86Sr, 𝛿𝛿18O and 𝛿𝛿D isotopes were used accordingly to better comprehend local hydrology and water use behaviour patterns of Black Box trees on the Calperum Floodplain, South Australia. Investigations were achieved by sampling and analysing local surface waters (Lake Merreti, Lake Clover, and River Murray), groundwater, soils (1.5 m depth) and plant material (stem water, and leaves) from two separate sites, north (Site 1) and south (Site 4). Considering the local hydrology, Lake Clover was composed of evaporated rainwater, while Lake Merreti was a relative mix of both evaporated rainwater and river water. Additionally, local rainfall sources appeared to vary overtime. Furthermore, groundwater showed no close relationship with rain water suggesting an alternative recharge source such as river water or remnant paleo-water. In terms of water use, linear mixing models using soil 87Sr/86Sr, leaf 87Sr/86Sr and stem water 𝛿𝛿18O inputs showed that Site 1 trees, on average, were predominately using rainwater (77%, 77% & 67%), while Site 4 trees used both rainwater (16%, 32% & 42%) and saline groundwater (70%, 62% & 58%), regardless of nearby lakes and streams. These findings have implications for future monitoring, and the management of outer floodplain Black Box populations that are unable to receive natural flooding inundation.<br>Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2018
45
Cameron, Heather. "Water regulation and population management : investigation into the impacts of dams and foxes on Murray River turtles and comparison of management strategies." Thesis, 2017. http://hdl.handle.net/1959.7/uws:47647.
Full textAbstract:
Freshwater turtle populations have been declining globally due to a combination of natural and anthropogenic factors, with nearly half of the world freshwater turtles threatened with extinction. Australia is high on the list of contributing countries, with one third of its native species threatened with extinction. The Murray River is an obvious example with populations of its native species Emydura macquarii declining by 69% and Chelodina longicollis declining by 91% over the past 30 years. Nest predation by the red fox and the installation of water regulators, which have affected dispersal and changed water quality, are likely main causes of these population declines This thesis used meta-population and population viability analyses to evaluate the impacts of dams on turtle populations in areas where recruitment may be severely limited because of predation by foxes. The aims are to determine levels of recruitment required throughout a system to eliminate risks of extinction, as well as determine how the placement of dams and weirs may restrict movement and potentially increase risks of extinction. I show that turtle populations of the Murray-Darling Basin (MDB) can sustain relatively high losses of source recruitment populations, if relief populations are located between dams and impoundments. Areas of South Australia are of most concern. The scarcity of available habitats between dams, combined with high nest predation rates, increases the risk of extinction significantly. Water quality is also another significant factor that has hastened population declines and led to localised extirpation of MDB turtle populations. Management of MDB turtles centres on increasing the number of source populations for several species, increasing connectivity between populations and minimising risks for species moving terrestrially. This study also used modelling and population viability analysis to compare the cost to benefit ratio of two management techniques; headstarting and 1080 poison baiting, to determine which management technique would require the least cost to be the most effective. Vortex modelling showed that headstarting is significantly more efficient, economically beneficial, and uniformly more successful than baiting. Headstarting cost up to 40 times cheaper than baiting yet produced the same results. Headstarting cost an average of $0.22 AUD per hectare, whilst baiting cost as much as $8.73 AUD per hectare. Furthermore, modelled headstarting success was unaffected by the proportion of waterbodies in an area, the proportion of waterbodies baited/supplemented into or the proportion of forests (areas of lower nest predation) present, and could be used uniformly throughout the river. However, baiting required more baits when a lower number of waterbodies and low proportion of forests were present and would therefore need to be tailored to the area.
46
Koehn, John Desmond. "The ecology and conservation management of Murray Cod Macullochella peelii peelii." 2006. http://repository.unimelb.edu.au/10187/2864.
Full textAbstract:
Murray cod Maccullochella peelii peelii is an iconic freshwater angling species that has suffered declines in abundance and is now listed as a nationally vulnerable species. Despite recognition of the need for biological knowledge to provide future management directions, little is known of its ecology. This thesis examines that ecology to provide new knowledge and recommendations for improved conservation management. (For complete abstract open document)
47
Eastburn, David. "Realizing the capacities of rural community institutions to manage ecologically strategic landscapes on behalf of Australian society." Phd thesis, 2010. http://hdl.handle.net/1885/146546.
Full text
48
Jensen, Anne Elizabeth. "The roles of seed banks and soil moisture in recruitment of semi-arid floodplain plants: the River Murray, Australia." 2008. http://hdl.handle.net/2440/49169.
Full textAbstract:
The decline of floodplain vegetation along the Lower River Murray, South Australia, has evoked recommendations for ‘environmental flows’ to restore and maintain the health of the ecosystem. To assist managers to maximize benefits from environmental flows, this thesis considers the significance of water for germination and recruitment in key floodplain plant species. Three dominant species are considered, including two trees, river red gum (Eucalyptus camaldulensis) and black box (E. largiflorens), and an understorey shrub, tangled lignum (Muehlenbeckia florulenta). The soil seed bank was dominated by terrestrial annual native plants. Among 1400 seedlings, a single river red gum was found, and no black box or lignum, suggesting that these species do not contribute to the persistent soil seed bank and rely instead on aerial seed banks (serotiny). Sampling of the soil seed bank was continued to determine when seed fall might coincide with appropriate soil moisture conditions. Responses of the soil seed bank to varied water regimes were compared to determine requirements for seedling survival. The results indicated that species richness, rapidity of response and survival time were all promoted by sustained soil moisture. Stands of eucalypts in various states of health (from very stressed to very healthy) were monitored to identify seasonal patterns in bud crops, flowering, fresh leaves and volumes of seed released from the aerial seed bank. Distinct seasonal phenological patterns were apparent, and suggested alternating flowering among individual trees (biennial for red gum, bi-annual for black box), producing an annual peak in summer. Peak seed rain occurred in summer (December–March) in healthy trees for both red gum and black box, with light seed rain continuing throughout the year. Seed fall from stressed trees was much reduced. Stressed trees responded after a second watering event, with much more varied and extended annual seed fall patterns. Lignum showed a spring peak in flowering and seed production. There was a prolific response of flowering and seeding to rainfall, but few seedlings survived. Vigorous vegetative growth occurred in existing plants in response to rainfall and watering but no new cloned plants were found during the study. An investigation of chromosomes as a potential tool to appraise the balance between sexual and asexual reproduction in lignum proved inconclusive, although a previous report of octoploidy in lignum was confirmed. Seeds from all three species and lignum cuttings were tested for their responses to varied watering regimes, based on combinations of simulated rain and flood conditions. The optimal soil moisture for continued growth and survival in all seeds and cuttings was 10 25%, with moisture values <10% causing wilting and death. The results also suggested that red gum and black box seeds which germinate in water under flooded conditions need to be stranded onto moist soil at the water’s edge within 10 days, for the seedling to continue to grow. It was also concluded that germination on rain-moistened soil is a key supplementary mechanism for recruitment, particularly between irregular flood events. For greatest benefit, the timing of environmental flows should complement any seasonal rainfall and irregular flooding that may occur. Extension of suitable soil moisture conditions (10-25%) for as long as possible after >5 mm rainfall, or after over-bank flows, would increase chances for survival of seedlings. December is the most likely month for maximal benefit from watering in the Lower Murray Valley, for germination and recruitment, based on regional rainfall and flooding patterns.<br>http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1344528<br>Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2008
49
Daghagh, Yazd Sahar. "Impacts of climatic variability, water scarcity and socio-economic demographics on farmers’ mental health in Australia." Thesis, 2019. http://hdl.handle.net/2440/122612.
Full textAbstract:
Climatic conditions in recent decades have been characterised with more frequent, long-term, and severely adverse events (e.g. drought) occurring in many countries. Many studies have found a link between various climatic evens and their negative impact on societies’ health, wellbeing and work productivity. In particular, there has been an increasing focus in the literature on the link between mental health and climatic variability, especially for rural communities. This is especially so for farming communities in Australia’s Murray-Darling Basin (MDB). MDB farmers have experienced significant increases in temperature and evaporation over the past three decades, and reductions in rainfall and runoff due to climate change. The main question investigated in this thesis was to try to understand the key stress factors affecting farmers’ mental health around the world, particularly focussing upon the consequences of climatic variability for farmers (both dryland and irrigators) in the MDB. To answer this question, a mixed-methods approach was employed involving: a) a systematic review of 167 articles on farmers’ mental health, using a standardised electronic literature search strategy and PRISMA guidelines, to understand the potential key stressors affecting farmers’ mental health around the world; b) Correlative Random Effects panel data regression analysis of MDB farmers’ (2,141 observations), and all Australian farmers (5,426 observations) mental health using 14 waves (2001-02 to 2014-15) of the national longitudinal survey from the ‘Household, Income and Labour Dynamics in Australia’ and utilising spatial analysis from various climate, agricultural and water databases (e.g. rainfall, drought periods, soil moisture, maximum summer temperatures); and c) Ordered Probit regression modelling of the influences on irrigator mental health, using a 2015-16 survey sample of 1,000 irrigators in the southern MDB, merged with a variety of spatial data (e.g. drought, water allocation and temperature). Key findings of this thesis show that water scarcity was associated with MDB farmers (both dryland and irrigators) worsening mental health. In particular, the most important proxies of water scarcity were found to be rainfall, low water allocations, and higher summer temperatures. Results also highlight the importance of financial capital in influencing southern MDB irrigators’ psychological distress, with net farm income, debt, productivity changes, and land capital value being the most important influences, respectively. This thesis also provides some evidence that landholder governance and natural resource management (such as being a certified organic irrigator) statistically positively influenced southern MDB irrigators’ mental health, especially in the horticultural industry (where larger sample sizes were available). These findings will become increasingly policy-relevant, given the increasing pressure placed on farming communities by the impacts of climate change, along with the fact that financial problems are increasing in drought-affected areas across Australia. Key recommendations of this thesis indicate the need for a strong focus on policy that is designed to build greater natural farming and financial capital on-farms, and encourage higher risk-management strategies to withstand a drier future in Australia. In summary, the focus must be to integrate: 1) drought/climate change policy; 2) mental health policy; 3) natural resource management/extension policy; and 4) rural economic and social development policy.<br>Thesis (Ph.D.) -- University of Adelaide, Centre for Global Food and Resources, 2019