Siga este link para ver outros tipos de publicações sobre o tema: Murray-Darling Basin, NSW.
Artigos de revistas sobre o tema "Murray-Darling Basin, NSW"
Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos
Veja os 50 melhores artigos de revistas para estudos sobre o assunto "Murray-Darling Basin, NSW".
Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.
Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.
Veja os artigos de revistas das mais diversas áreas científicas e compile uma bibliografia correta.
1
Maini, N., A. Buchan e S. Joseph. "Derivation of a salinity target for the Lower Murray Darling Valley". Water Science and Technology 48, n.º 7 (1 de outubro de 2003): 105–12. http://dx.doi.org/10.2166/wst.2003.0430.
Texto completo da fonteResumo:
The NSW Government commissioned catchment management boards (CMBs) to set the direction and process for catchment scale natural resource management. In the Lower Murray Darling, Rivers are highly regulated and water resources shared between three states. The Catchment Board only has jurisdiction over the northern bank of the Murray but salt and water enter the river from many locations upstream and along the area boundary. River salt and flow modelling has continually been improved to reflect and contribute to an increased understanding of salinity processes. The MDBC Salt Load study correlates 10 years of actual measured data with its modelled outputs, and estimates river salinities for 2020, 2050 and 2100. Routing models such as SALTFLO and MURKEY generate percentile salinity levels at different nodes in the River Murray downstream of the Lower Darling confluence. National, Murray-Darling Basin and NSW salinity management policy and legislative requirements were considered, MDBC model output was used to ensure the interim targets are achievable, auditable, and appropriate to the catchment. The method for an end-of-valley river based target for salinity is described. A target of less than 463 μS/cm for Lock 6, a point in the lower reaches of the Murray River is recommended for year 2010. Catchment management targets that express the main river salinity risk in five hydrologically distinct management zones are also recommended. Salinity management changes are needed in each zone to meet the end-of-valley target.
2
Stewart, G., e B. Harper. "Barmah-Millewa forest environmental water allocation". Water Science and Technology 45, n.º 11 (1 de junho de 2002): 217–23. http://dx.doi.org/10.2166/wst.2002.0398.
Texto completo da fonteResumo:
The formal allocation of water for the environment is a developing area of river management both scientifically and in terms of community participation. This case study, illustrating the recent use of the Barmah-Millewa Forest Environmental Water Allocation (EWA), provides a practical demonstration of community participation in environmental water management, the application of hydrological and biological “triggers” and a positive, demonstrable biological outcome from an environmental water allocation. The Barmah-Millewa Forest covers an area of 70,000 ha across the floodplain of the Murray River, upstream of the town of Echuca. About half the forest is in NSW (Millewa) and half is in Victoria (Barmah). The Barmah Forest is a Wetland of International Importance listed under the Convention on Wetlands - Ramsar Convention. The forest is the largest river redgum forest in the world. The natural flooding cycle associated with the forest has been significantly altered by regulation of the Murray River - impacting upon the overall health of the forest ecosystem. Recognising this, the Murray Darling Basin Commission developed a water management strategy for the forest to enhance forest, fish and wildlife values. To implement this strategy, between 1990 and 1993 reports were completed and community consultation took place. In 1993 the Murray Darling Basin Ministerial Council approved allocation of 100 Gigalitres of water per year, provided in equal shares by NSW and Victoria, to meet the needs of the forest ecosystem and in 1994 the Barmah-Millewa Forum was established under the Murray-Darling Basin Agreement. The vision for the Forum is to maintain and, where possible, improve the ecological and productive sustainability of the Barmah-Millewa Forest and to establish a planning and operational framework to better meet the flooding and drying requirements of the riparian forests and wetlands. Between October 2000 and January 2001 the Barmah-Millewa Forest Environmental Water Allocation was used for the second time. A total of 341 GL was released as an EWA. This amount represented only 8% of the total flows downstream of Yarrawonga Weir from September 2000 and January 2001. The strategic use of the relatively small amount of water enabled flooding to be maintained and ensured significant breeding success for water birds and other biota in the Forest.
3
Marshall, Graham R. "Evaluating Adaptive Efficiency in Environmental Water Recovery: Application of a Framework for Institutional Cost-Effectiveness Analysis". Water Economics and Policy 06, n.º 02 (abril de 2020): 2050003. http://dx.doi.org/10.1142/s2382624x20500034.
Texto completo da fonteResumo:
The first empirical application of an established framework for evaluating the adaptive efficiency of policy and project options — the Institutional Cost-Effectiveness Analysis (ICEA) framework — is documented in this paper. The application involves cost-effectiveness comparison of six projects for environmental water recovery in the Murray-Darling Basin, Australia, managed by the New South Wales (NSW) Government under three programs: The Living Murray Initiative; the NSW Wetland Recovery Program; and the NSW Rivers Environmental Restoration Program. Focussing primarily on one of the projects — the Darling Anabranch Pipeline Project (DAPP) — allows an in-depth account to be presented of the ICEA framework’s application. Abatement and transaction costs, and public and private subsets of these costs, were accounted for in the applications. The adaptive efficiency of the DAPP (a “water-saving project”) is found provisionally — i.e., without accounting quantitatively for institutional lock-in costs — to exceed that of the five other environmental water recovery projects (including two “market-purchase projects”) evaluated. This finding is significant given a tendency for economists to presume that environmental water recovery is generally achieved more efficiently through market-purchase projects. With water management, and environmental management more broadly, exposed to increasing uncertainty, adaptive efficiency will grow in importance as a metric for economic evaluation. The application of the ICEA framework documented in this paper can guide researchers in applying this metric to evaluations of projects and policies implemented in, or proposed for, this domain.
4
Becker, Joy, Dean Gilligan, Martin Asmus, Alison Tweedie e Richard Whittington. "Geographic Distribution of Epizootic haematopoietic necrosis virus (EHNV) in Freshwater Fish in South Eastern Australia: Lost Opportunity for a Notifiable Pathogen to Expand Its Geographic Range". Viruses 11, n.º 4 (1 de abril de 2019): 315. http://dx.doi.org/10.3390/v11040315.
Texto completo da fonteResumo:
Epizootic haematopoietic necrosis virus (EHNV) was originally detected in Victoria, Australia in 1984. It spread rapidly over two decades with epidemic mortality events in wild redfin perch (Perca fluviatilis) and mild disease in farmed rainbow trout (Oncorhynchus mykiss) being documented across southeastern Australia in New South Wales (NSW), the Australian Capital Territory (ACT), Victoria, and South Australia. We conducted a survey for EHNV between July 2007 and June 2011. The disease occurred in juvenile redfin perch in ACT in December 2008, and in NSW in December 2009 and December 2010. Based on testing 3622 tissue and 492 blood samples collected from fish across southeastern Australia, it was concluded that EHNV was most likely absent from redfin perch outside the endemic area in the upper Murrumbidgee River catchment in the Murray–Darling Basin (MDB), and it was not detected in other fish species. The frequency of outbreaks in redfin perch has diminished over time, and there have been no reports since 2012. As the disease is notifiable and a range of fish species are known to be susceptible to EHNV, existing policies to reduce the likelihood of spreading out of the endemic area are justified.
5
Dabovic, Jodie, Lucy Dobbs, Glenn Byrne e Allan Raine. "A new approach to prioritising groundwater dependent vegetation communities to inform groundwater management in New South Wales, Australia". Australian Journal of Botany 67, n.º 5 (2019): 397. http://dx.doi.org/10.1071/bt18213.
Texto completo da fonteResumo:
Groundwater dependent ecosystems (GDEs) require access to groundwater to meet all or some of their water requirements to maintain community structure and function. The increasing demand of surface and groundwater resources has seen the NSW Government put in place management mechanisms to enable the sharing of water between irrigators, the environment, industry, towns and communities via water sharing plans. The groundwater sharing plans aim to provide adaptive management of GDEs by prioritising for protection those that are considered the most ecologically valuable within each plan area. The High Ecological Value Aquatic Ecosystems (HEVAE) framework has already been adopted to prioritise riverine ecosystems for management in surface water sharing plans. Here, we provide a method developed using the HEVAE framework to prioritise vegetation GDEs for management. The GDE HEVAE methods provide a derived ecological value dataset for identified groundwater dependent vegetation that is used to inform the planning and policy decisions in NSW. These decisions are required to manage and mitigate current and future risks caused by groundwater extraction. This is achieved via the identification of ecologically valuable assets to then use as the consequence component in a risk assessment for the groundwater sources, to provide vegetation GDE locations for setback distances for new groundwater production bores, and for the assessment of impacts due to current and potential future groundwater extraction. The GDE HEVAE method uses recorded and predicted spatial data to provide weighted scores for each attribute associated with the four HEVAE criteria (distinctiveness, diversity, vital habitat and naturalness). The combined scores categorise the ecological value of each groundwater dependent vegetation community (depicted as geographic information system (GIS) polygon features) from very high to very low. We apply the GDE HEVAE method to three catchments in order to demonstrate the method’s applicability across the Murray–Darling Basin with varying elevation and climate characteristics. The ecological value outcomes derived from the methods have been used to inform planning and policy decisions by NSW Government processes to allow for protection in not only areas that are currently at risk but to also manage for potential future risks from groundwater extraction.
6
FitzSimons, Trish. "Catherine Potter, Sarah Moles, Libby Connors and Pam Postle, eds. Conversations on the Condamine: An Oral History from the Murray Darling Basin. Annandale NSW: Envirobook, 2002. 128 + vii pp. $19.95." Queensland Review 10, n.º 1 (maio de 2003): 175–76. http://dx.doi.org/10.1017/s1321816600002609.
Texto completo da fonte
7
VÖRÖS, JUDIT, SKYE WASSENS, LUKE PRICE, DAVID HUNTER, STEVEN MYERS, KYLE ARMSTRONG, MICHAEL J. MAHONY e STEPHEN DONNELLAN. "Molecular systematic analysis demonstrates that the threatened southern bell frog, Litoria raniformis (Anura: Pelodryadidae) of eastern Australia, comprises two sub-species". Zootaxa 5228, n.º 1 (11 de janeiro de 2023): 1–43. http://dx.doi.org/10.11646/zootaxa.5228.1.1.
Texto completo da fonteResumo:
In south-eastern Australia, the pelodryadid Litoria aurea Group (sensu Tyler & Davies 1978) comprises three species: Litoria aurea (Lesson, 1829), Litoria raniformis (Keferstein, 1867), and Litoria castanea (Steindachner, 1867). All three species have been subject to declines over recent decades and taxonomic uncertainty persists among populations on the tablelands in New South Wales. We address the systematics of the Group by analysing mitochondrial and nuclear DNA sequences to assess divergence in the Litoria raniformis from across its current range in New South Wales (NSW), Victoria, South Australia (SA) and Tasmania. We also included samples of Litoria castanea from a recently rediscovered population in the southern tablelands of NSW. Our phylogenetic and population genetic analyses show that Litoria raniformis comprises northern and southern lineages, showing deep mitochondrial DNA sequence divergence (7% net average sequence divergence) and can be diagnosed by fixed allelic differences at more than 4,000 SNP loci. Samples of the northern lineage were collected from the Murray-Darling Basin while those of the southern lineage were collected from south-eastern South Australia, southern and south-eastern Victoria and Tasmania. Analysis of the morphology and bioacoustics did not unequivocally delineate the two lineages. The presence of a hybrid backcross individual in western Victoria at the northern margin of the southern lineage, leads us to assign sub-species status to the two lineages, L. r. raniformis for the northern lineage and L. r. major for the southern lineage. Our data do not unequivocally resolve the taxonomic status of L. castanea which will require molecular genetic analyses of museum vouchers from those parts of the range where L. castanea and L. raniformis are no longer extant. Our data also suggest that human mediated movement of frogs may have occurred over the past 50 years. Our genotyping of vouchers collected in the 1970s from the Mount Lofty Ranges in South Australia detected mitochondrial haplotypes of both sub-species and SNP analysis showed that a single Tasmanian specimen was a backcross with L. r. raniformis ancestry. Movement of L. r. raniformis into Tasmania and both sub-species into the Mount Lofty Ranges are not likely due to passive movements of animals through agricultural commerce, but due to the attractiveness of the species as pets and subsequent escapes or releases, potentially of the larval life stage.
8
O'Neill, C. J., E. Humphreys, J. Louis e A. Katupitiya. "Maize productivity in southern New South Wales under furrow and pressurised irrigation". Australian Journal of Experimental Agriculture 48, n.º 3 (2008): 285. http://dx.doi.org/10.1071/ea06093.
Texto completo da fonteResumo:
Irrigation farmers in the Murray–Darling Basin of Australia are under considerable pressure to reduce the amount of water they use for irrigation, while sustaining production and profitability. Changing from surface to pressurised irrigation systems may provide some or all of these outcomes; however, little is known about the performance of alternative irrigation methods for broadacre annual crops in this region. Therefore, a demonstration site for comparing furrow, subsurface drip and sprinkler irrigation was established on a representative clay soil in the Coleambally Irrigation Area, NSW. The performance of maize (Zea mays L.) under the three irrigation systems was compared during the 2004–05 season. Subsurface drip irrigated maize out-performed sprinkler and furrow irrigated maize in terms of grain yield (drip 11.8 t/ha, sprinkler 10.5 t/ha, furrow 10.1 t/ha at 14% moisture), net irrigation water application (drip 5.1 ML/ha, sprinkler 6.2 ML/ha, furrow 5.3 ML/ha), net irrigation water productivity (drip 2.3 t/ML, sprinkler 1.7 t/ML, furrow 1.9 t/ML) and total water productivity (drip 1.7 t/ML, sprinkler 1.4 t/ML, furrow 1.3 t/ML). Thus, subsurface drip irrigation saved ~30% of the total amount of water (irrigation, rain, soil water) needed to produce the same quantity of grain using furrow irrigation, while sprinkler irrigation saved ~8% of the water used. The higher net irrigation with sprinkler irrigation was largely due to the lower soil water content in the sprinkler block at the time of sowing. An EM31 survey indicated considerable spatial soil variability within each irrigation block, and all irrigation systems had spatially variable water distribution. Yield variability was very high within all irrigation systems, and appeared to be more strongly associated with irrigation variability than soil variability. All irrigation blocks had large patches of early senescence and poor cob fill, which appeared to be due to nitrogen and/or water deficit stress. We expect that crop performance under all irrigation systems can be improved by improving irrigation, soil and N management.
9
Faulks, Leanne K., Dean M. Gilligan e Luciano B. Beheregaray. "Phylogeography of a threatened freshwater fish (Mogurnda adspersa) in eastern Australia: conservation implications". Marine and Freshwater Research 59, n.º 1 (2008): 89. http://dx.doi.org/10.1071/mf07167.
Texto completo da fonteResumo:
Phylogeography is a field that has the potential to provide an integrative approach to the conservation of threatened species. The southern purple spotted gudgeon, Mogurnda adspersa, is a small freshwater fish that was once common and widely distributed throughout south-eastern Australia. However, habitat alteration has dramatically reduced the size and the range of Murray–Darling Basin populations, which are now classified as endangered. Here patterns of genetic structure and evolutionary history of M. adspersa in southern Queensland and the Murray–Darling Basin are elucidated using three regions of the mitochondrial DNA, the ATPase 6 and 8 and the control region. Murray–Darling Basin populations are characterised by lineages with highly localised endemism, very low genetic diversity and restricted gene flow. Phylogenetic reconstructions show that Murray–Darling Basin populations comprise a monophyletic clade that possibly originated by range expansion from the coast around 1.6 million years ago. It is proposed that the divergent Murray–Darling Basin clade is of high conservation priority and requires separate management. The present study further exemplifies the role of drainage rearrangement in driving evolutionary diversification in Australian freshwater fishes, an historical process with profound implications for conservation management.
10
Musyl, MK, e CP Keenan. "Population genetics and zoogeography of Australian freshwater golden perch, Macquaria ambigua (Richardson 1845) (Teleostei: Percichthyidae), and electrophoretic identification of a new species from the Lake Eyre basin". Marine and Freshwater Research 43, n.º 6 (1992): 1585. http://dx.doi.org/10.1071/mf9921585.
Texto completo da fonteResumo:
Populations of golden perch (Macquaria ambigua) were sampled from both sides of the Great Dividing Range (GDR): from the Murray-Darling drainage basin (Murray R., L. Keepit and Condamine R.), the L. Eyre internal drainage basin (Barcoo R. and Diamantina R.), and the internal drainage basin of the Bulloo R.-all to the west of the GDR-and from the Fitzroy drainage basin (Dawson R. and Nogoa R.) east of the GDR. Starch-gel and polyacrylamide electrophoresis of 12 enzyme systems plus two general muscle proteins was used to estimate the genetic variation within and between populations. Of the 18 presumed genetic loci examined, nine were either polymorphic at the P0.99 criterion level or exhibited fixed allelic differences between some of the populations. Within the Murray-Darling drainage basin, there was little indication of heterogeneity. Contingency Χ2 analyses of allelic distributions among drainage basins indicated significant levels of heterogeneity at six variable loci. The isolated L. Eyre population exhibited diagnostic alleles at four loci when compared with the Murray- Darling and Fitzroy populations. The genetic distance of the L. Eyre population (Nei's D=0.23) from these two populations indicates that the L. Eyre golden perch is most probably a previously unrecognized allopatric species. The level of divergence (0 = 0.06) between Fitzroy and Murray-Darling golden perch indicates differentiation at the subspecies level, with no fixed differences observed between these two populations. Finally, golden perch from the Bulloo R. represent either (i) an intermediate evolutionary unit between the presumed ancestral L. Eyre population and the derived Murray-Darling and Fitzroy populations or (ii) a complex hybrid between these populations. Average gene-flow statistics, FST = 0.760 and Nem=0.08, suggest that the populations in each of the four basins can be regarded as separate gene pools that have been isolated for different, and considerable, periods of time.
11
Hart, Barry, Glen Walker, Asitha Katupitiya e Jane Doolan. "Salinity Management in the Murray–Darling Basin, Australia". Water 12, n.º 6 (26 de junho de 2020): 1829. http://dx.doi.org/10.3390/w12061829.
Texto completo da fonteResumo:
The southern Murray–Darling Basin (MDB) is particularly vulnerable to salinity problems. Much of the Basin’s landscape and underlying groundwater is naturally saline with groundwater not being suitable for human or irrigation use. Since European settlement in the early 1800s, two actions—the clearance of deep-rooted native vegetation for dryland agriculture and the development of irrigation systems on the Riverine Plains and Mallee region—have resulted in more water now entering the groundwater systems, resulting in mobilization of the salt to the land surface and to rivers. While salinity has been a known issue since the 1960s, it was only in the mid-1980s that was recognized as one of the most significant environmental and economic challenges facing the MDB. Concerted and cooperative action since 1988 by the Commonwealth and Basin state governments under a salinity management approach implemented over the past 30 years has resulted in salinity now being largely under control, but still requiring on-going active management into the future. The approach has involved the development of three consecutive salinity strategies governing actions from 1988 to 2000, from 2001 to 2015, and the most recent from 2016 to 2030. The basis of the approach and all three strategies is an innovative, world-leading salinity management framework consisting of: An agreed salinity target; joint works and measures to reduce salt entering the rivers; and an agreed accountability and governance system consisting of a system of salinity credits to offset debits, a robust and agreed method to quantify the credits and debits, and a salinity register to keep track of credits and debits. This paper first provides background to the salinity issue in the MDB, then reviews the three salinity management strategies, the various actions that have been implemented through these strategies to control salinity, and the role of the recent Basin Plan in salinity management. We then discuss the future of salinity in the MDB given that climate change is forecast to lead to a hotter, drier and more variable climate (particularly more frequent droughts), and that increased salt loads to the River Murray are predicted to come from the lower reaches of the Mallee region. Finally, we identify the key success factors of the program.
12
Unmack, P. J., M. J. Young, B. Gruber, D. White, A. Kilian, X. Zhang e A. Georges. "Phylogeography and species delimitation of Cherax destructor (Decapoda: Parastacidae) using genome-wide SNPs". Marine and Freshwater Research 70, n.º 6 (2019): 857. http://dx.doi.org/10.1071/mf18347.
Texto completo da fonteResumo:
Cherax is a genus of 58 species of decapod crustaceans that are widespread across Australia and New Guinea. We use single-nucleotide polymorphisms (SNPs) to examine phylogeographic patterns in the most widespread species of Cherax, namely, C. destructor, and test the distinctiveness of one undescribed species, two C. destructor subspecies, previously proposed evolutionarily significant units, and management units. Both the phylogenetic analyses and the analysis of fixed allelic differences between populations support the current species-level taxonomy of C. setosus, C. depressus, C. dispar and C. destructor, the distinctiveness of C. destructor albidus and C. d. destructor and the existence of one undescribed species. The two populations of C. d. albidus from the Glenelg and Wimmera rivers were significantly distinct, with eight diagnostic differences (<1% fixed differences, null expectation is four fixed differences), but this low level of divergence is interpreted as within the range that might be expected of management units, that is, among allopatric populations of a single species or subspecies. A southern clade of C. d. destructor comprising the Murray River and its tributaries upstream from its confluence with the Darling River is genetically distinct from a northern clade comprising populations from the Lake Eyre Basin, the northern half of the Murray–Darling Basin (Darling River catchment) and the Lower Murray River below the Darling confluence.
13
Gell, Peter A. "Watching the tide roll away – contested interpretations of the nature of the Lower Lakes of the Murray Darling Basin". Pacific Conservation Biology 26, n.º 2 (2020): 130. http://dx.doi.org/10.1071/pc18085.
Texto completo da fonteResumo:
The Murray Darling Basin Plan (Murray Darling Basin Authority 2012) represents the largest investment by government in an Australian environmental management challenge and remains highly conflicted owing to the contested allocation of diminishing water resources. Central to the decision to reallocate consumptive water to environmental purposes in this Plan was the case made to maintain the freshwater character of two lakes at the terminus of the Murray Darling Basin, in South Australia. This freshwater state was identified as the natural condition on the basis of selected anecdotal evidence and was enshrined in the site’s listing under the Ramsar Convention. The commitment to the freshwater state was challenged under drought when sea water was seen as a means of averting acidification when low river flows risked the exposure of sulfidic sediments. Independent evidence from water quality indicators (diatoms) preserved in lake sediment records, however, attested to an estuarine, albeit variable, condition before the commissioning of near-mouth barrages in 1940. This interpretation for a naturally estuarine history, published after peer review, was overlooked in a report to the South Australian government, which argued, without the provision of new evidence from the lakes, that they were fresh for their entire history. This revised interpretation is widely cited in the scientific literature, government reports and online discussion and underpins a watering strategy aimed at a freshwater future for the Lower Lakes. The allocation of large volumes of fresh water to achieve this condition presents significant difficulties owing to the highly contested nature of water use across the Basin.
14
Gell, Peter A. "Corrigendum to: Watching the tide roll away – contested interpretations of the nature of the Lower Lakes of the Murray Darling Basin". Pacific Conservation Biology 26, n.º 2 (2020): 211. http://dx.doi.org/10.1071/pc18085_co.
Texto completo da fonteResumo:
The Murray Darling Basin Plan (Murray Darling Basin Authority 2012) represents the largest investment by government in an Australian environmental management challenge and remains highly conflicted owing to the contested allocation of diminishing water resources. Central to the decision to reallocate consumptive water to environmental purposes in this Plan was the case made to maintain the freshwater character of two lakes at the terminus of the Murray Darling Basin, in South Australia. This freshwater state was identified as the natural condition on the basis of selected anecdotal evidence and was enshrined in the site's listing under the Ramsar Convention. The commitment to the freshwater state was challenged under drought when sea water was seen as a means of averting acidification when low river flows risked the exposure of sulfidic sediments. Independent evidence from water quality indicators (diatoms) preserved in lake sediment records, however, attested to an estuarine, albeit variable, condition before the commissioning of near-mouth barrages in 1940. This interpretation for a naturally estuarine history, published after peer review, was overlooked in a report to the South Australian government, which argued, without the provision of new evidence from the lakes, that they were fresh for their entire history. This revised interpretation is widely cited in the scientific literature, government reports and online discussion and underpins a watering strategy aimed at a freshwater future for the Lower Lakes. The allocation of large volumes of fresh water to achieve this condition presents significant difficulties owing to the highly contested nature of water use across the Basin.
15
T. Kingsford, Richard. "Managing Australia's Scarce Water Resources for the Environment". Pacific Conservation Biology 15, n.º 1 (2009): 4. http://dx.doi.org/10.1071/pc090004.
Texto completo da fonteResumo:
Australia has 12 major drainage basins, but most water use and extraction comes from the Murray- Darling Basin, despite not having Australia?s more populous cities. About 66% of surface water use in Australia is extracted from the rivers of the Murray-Darling Basin (NLWRA 2001). The ecological impacts are widespread and insurmountable: key ecosystems are in various stages of collapse. Many of these are conservation reserves and wetlands recognized for their international importance under the Ramsar Convention. Populations of native fish species are considered to be only at 10% of pre European levels with 46% of the 35 fish species now listed as threatened at state level (MDBC 2004). Waterbird populations are also declining significantly, sometimes up to 80% over a period of about 25 years (Kingsford and Thomas 2004; Nebel et al. 2008). Many communities of floodplain vegetation are also in decline. The River Murray no longer breaks through the sand barriers to naturally flow out to sea, with flow now only maintained by a dredge (costing ~$100,000 per week) to ensure that sand does not completely block the Murray mouth. The lower lakes are below sea level for the first time in more than 7,000 years and marine incursions into this freshwater ecosystem have allowed colonies of marine worms Ficopomatus enigmaticus to build their calcareous colonies on the backs of freshwater turtles and crabs weighing them down.
16
Humphries, Paul. "Wilhelm Blandowski’s contribution to ichthyology of the Murray-Darling Basin, Australia". Proceedings of the Royal Society of Victoria 121, n.º 1 (2009): 90. http://dx.doi.org/10.1071/rs09090.
Texto completo da fonteResumo:
Wilhelm Blandowski is best known for the scandal that surrounded his attempts to name a number of new species of freshwater fish after prominent members of the Victorian scientific establishment. Although this 19th Century anecdote is diverting, it belies, I believe, the significant contribution that the first paid Victorian government zoologist made to the ichthyology of the Murray-Darling Basin. Although his claim to new species was exaggerated, his collections, assisted by Gerard Krefft were the most diverse to that date. There is no doubt – because Blandowski tells us as much – that the expedition’s success in collecting so many species, as well as information on distribution, habitat, size and diet, can be attributed to the knowledge of the local Aboriginal people, the Nyeri Nyeri. That Blandowski realised that this knowledge existed and acknowledged it, is unusual for the time. The information provided, although broadly consistent with what we know of the species’ current habits, is scanty and there is some uncertainty as to the location where most of the species were collected. Interpretations based on illustrations, written descriptions and extant specimens suggest that many species that were collected in 1856/57 no longer occur in that region of the Murray-Darling Basin. Blandowski’s collections also hint at the possibility that the distribution of the spotted galaxias, Galaxias truttaceus Valenciennes 1846, normally considered coastal, may have formerly extended much further up into freshwater.
17
McLeod, SR, RB Hacker e JP Druhan. "Managing the commercial harvest of kangaroos in the Murray-Darling Basin." Australian Mammalogy 26, n.º 1 (2004): 9. http://dx.doi.org/10.1071/am04009.
Texto completo da fonteResumo:
In this study a new, physiologically structured model of kangaroo population dynamics is described. The model has been used to examine a wide range of harvest rate � sex ratio combinations, following a simple harvest strategy where the quota was proportional to population size. The combinations of harvest rate and sex ratio in the harvest that best suited the objectives of the stakeholder groups (non-Government conservationists, wildlife management agencies, the kangaroo industry and pastoralists) were identified using multicriteria decision analysis. The best combinations for the stakeholder groups non-Government conservationists, wildlife management agencies and the kangaroo industry were characterised by a strong male bias (90 ? 100% male) and low to moderate harvest rates (10 ? 40% per annum). The best solutions for pastoralists were female biased (at least 70% females) with high harvest rates (90% per annum).
18
Koehn, John D., Stephen R. Balcombe, Lee J. Baumgartner, Christopher M. Bice, Kate Burndred, Iain Ellis, Wayne M. Koster et al. "What is needed to restore native fishes in Australia’s Murray–Darling Basin?" Marine and Freshwater Research 71, n.º 11 (2020): 1464. http://dx.doi.org/10.1071/mf20248.
Texto completo da fonteResumo:
The Murray–Darling Basin (MDB) is Australia’s food bowl, contributing 40% of agricultural production and supporting a population of over 4 million people. Historically, the MDB supported a unique native fish community with significant cultural, subsistence, recreational, commercial and ecological values. Approximately one-quarter of the MDB’s native species are endemic. Changes to river flows and habitats have led to a >90% decline in native fish populations over the past 150 years, with almost half the species now of conservation concern. Commercial fisheries have collapsed, and important traditional cultural practices of First Nations People have been weakened. The past 20 years have seen significant advances in the scientific understanding of native fish ecology, the effects of human-related activities and the recovery measures needed. The science is well established, and some robust restoration-enabling policies have been initiated to underpin actions. What is now required is the political vision and commitment to support investment to drive long-term recovery. We present a summary of 30 priority activities urgently needed to restore MDB native fishes.
19
Blackmore, Don, e Daniel Connell. "Are rural land practices in the Murray-Darling Basin a threat to the environment?" Soil Research 35, n.º 5 (1997): 1037. http://dx.doi.org/10.1071/s96109.
Texto completo da fonteResumo:
Over the last 150 years Australia has gained great economic rewards from the use of the natural resources of the Murray-Darling Basin. However, many of the methods used to gain those benefits are now seen as unsustainable. To maintain the region’s productivity in the future, a different approach to managing its natural resources is needed. This paper explains the economic and environmental importance of the Basin, describes the degradation that has occurred, and summarises the efforts being made to achieve sustainable management of the region.
20
Higgisson, William, Sue Briggs e Fiona Dyer. "Responses of nitre goosefoot (Chenopodium nitrariaceum) to simulated rainfall and depth and duration of experimental flooding". Marine and Freshwater Research 70, n.º 4 (2019): 493. http://dx.doi.org/10.1071/mf18161.
Texto completo da fonteResumo:
Nitre goosefoot (Chenopodium nitrariaceum (F.Muell.) is a woody shrub that occurs at the edges of floodplains and other intermittently flooded areas across the Murray–Darling Basin. No studies have been conducted on the hydrological requirements of nitre goosefoot, and the species is not considered in watering requirements of floodplain species of the Murray–Darling Basin. This study investigated the effects of simulated rainfall and depth and duration of experimental flooding on mortality, leaf production, biomass and seed production of nitre goosefoot. Nitre goosefoot plants were grown from seeds collected near Hillston, New South Wales, Australia. The plants were subjected to the following 14 hydrological treatments: dry (no water applied), rainfall (simulating rainfall conditions at Hillston) and 12 combinations of three water depths (10cm, 50cm, 75cm) with four durations of inundation (5 days, 10 days, 20 days, 40 days). The study found that nitre goosefoot plants survived flooding, providing plants were not totally submerged, leaf production increased during flooding and after drawdown, and leaf production, biomass and seeding were highest under shallow flooding for approximately 1 month. The results of the study allow the hydrological requirements of nitre goosefoot to be considered in environmental watering programs.
21
Prosser, Ian P., Francis H. S. Chiew e Mark Stafford Smith. "Adapting Water Management to Climate Change in the Murray–Darling Basin, Australia". Water 13, n.º 18 (12 de setembro de 2021): 2504. http://dx.doi.org/10.3390/w13182504.
Texto completo da fonteResumo:
Climate change is threatening water security in water-scarce regions across the world, challenging water management policy in terms of how best to adapt. Transformative new approaches have been proposed, but management policies remain largely the same in many instances, and there are claims that good current management practice is well adapted. This paper takes the case of the Murray–Darling Basin, Australia, where management policies are highly sophisticated and have been through a recent transformation in order to critically review how well adapted the basin’s management is to climate change. This paper synthesizes published data, recent literature, and water plans in order to evaluate the outcomes of water management policy. It identifies several limitations and inequities that could emerge in the context of climate change and, through synthesis of the broader climate adaptation literature, proposes solutions that can be implemented when basin management is formally reviewed in 2026.
22
Barton, Diane P., Xiaocheng Zhu, Alara Nuhoglu, Luke Pearce, Matthew McLellan e Shokoofeh Shamsi. "Parasites of Selected Freshwater Snails in the Eastern Murray Darling Basin, Australia". International Journal of Environmental Research and Public Health 19, n.º 12 (13 de junho de 2022): 7236. http://dx.doi.org/10.3390/ijerph19127236.
Texto completo da fonteResumo:
Aquatic snails serve an important role in the ecosystem. They also play an essential role in the life cycle of many parasites as hosts and may pose risks to animal and human health. In Australia, the role of snails in the transmission of parasites of livestock is well studied. However, despite the country’s unique biodiversity and wildlife, little is known about the role of snails in the transmission and survival of parasites in other ecosystems, including aquatic and aquaculture systems. This study aimed to determine the occurrence of parasites in freshwater snails in the eastern Murray Darling Basin. A total of 275 snails were collected from various localities, including aquaculture fishery ponds and natural creeks during the summer and autumn months in the southern hemisphere. Three different species of freshwater snails, all common to the area, were found, including Bullastra lessoni (n = 11), Isidorella hainesii (n = 157), and Haitia acuta (n = 107), of which 9.1%, 1.3%, and 4.7%, respectively, were found to be harboring various developmental stages of Trematoda. No other parasite was found in the examined snails. Parasites were identified as Choanocotyle hobbsi, Plagiorchis sp. and Petasiger sp. based on the sequences of their ITS2, 18S, and 28S ribosomal DNA region. Herein, we report a native parasite Choanocotyle hobbsi in an introduced snail, Haitia acuta, from both natural and aquaculture ponds. As there are no genetic sequences for adult specimens of Petasiger spp. and Plagiorchis spp. collected in Australia for comparison, whether the specimens collected in this study are the larval stage of one of the previously described species or are a new, undescribed species cannot yet be determined. Our results also suggest snails collected from aquaculture ponds may be infected with considerably more parasites.
23
Wedderburn, S. D., C. M. Bice e T. C. Barnes. "Prey selection and diet overlap of native golden perch and alien redfin perch under contrasting hydrological conditions". Australian Journal of Zoology 62, n.º 5 (2014): 374. http://dx.doi.org/10.1071/zo14018.
Texto completo da fonteResumo:
Many freshwater fishes have been introduced outside their natural range. The consequences have included the decline or extinction of native fishes, principally due to competition and predation. Redfin perch (Perca fluviatilis) is a highly efficient predatory fish species that was introduced to Australia in the 1800s. It now has a broad distribution in the Murray–Darling Basin, but its impacts on native fishes are largely unstudied. It often cohabits with native golden perch (Macquaria ambigua ambigua), which is similar from a trophic ecomorphology perspective. We examine prey selection and diet overlap of adult redfin perch and golden perch under contrasting hydrological conditions in terminating lakes of the Murray–Darling Basin. Prey selection by both species varied substantially between drought and flood conditions. Diet overlap of redfin perch and golden perch was significant only during flood, and was apparently related to pelagic prey availability. There were dietary differences during drought that imply that resource partitioning occurred between the perches, possibly because competitive interactions were intensified. Conversely, the promotion of pelagic prey fishes during flooding apparently facilitated resource sharing. The findings suggest that redfin perch can directly compete with native piscivores for prey. The potential impacts on native piscivores and small-bodied fish populations warrant further experimental and field investigations.
24
Gippel, C., T. Jacobs e T. McLeod. "Environmental flows and water quality objectives for the River Murray". Water Science and Technology 45, n.º 11 (1 de junho de 2002): 251–60. http://dx.doi.org/10.2166/wst.2002.0402.
Texto completo da fonteResumo:
Over the past decade, there intense consideration of managing flows in the River Murray to provide environmental benefits. In 1990 the Murray-Darling Basin Ministerial Council adopted a water quality policy: To maintain and, where necessary, improve existing water quality in the rivers of the Murray-Darling Basin for all beneficial uses - agricultural, environmental, urban, industrial and recreational, and in 1994 a flow policy: To maintain and where necessary improve existing flow regimes in the waterways of the Murray-Darling Basin to protect and enhance the riverine environment. The Audit of Water Use followed in 1995, culminating in the decision of the Ministerial Council to implement an interim cap on new diversions for consumptive use (the “Cap”) in a bid to halt declining river health. In March 1999 the Environmental Flows and Water Quality Objectives for the River Murray Project (the Project) was set up, primarily to establish water quality and environmental flow objectives for the River Murray system. A Flow Management Plan will be developed that aims to achieve a sustainable river environment and water quality, in accordance with community needs, and including an adaptive approach to management and operation of the River. It will lead to objectives for water quality and environmental flows that are feasible, appropriate, have the support of the scientific, management and stakeholder communities, and carry acceptable levels of risk. This paper describes four key aspects of the process being undertaken to determine the objectives, and design the flow options that will meet those objectives: establishment of an appropriate technical, advisory and administrative framework; establishing clear evidence for regulation impacts; undergoing assessment of environmental flow needs; and filling knowledge gaps. A review of the impacts of flow regulation on the health of the River Murray revealed evidence for decline, but the case for flow regulation as the main cause is circumstantial or uncertain. This is to be expected, because the decline of the River Murray results from many factors acting over a long period. Also, the health of the river varies along its length, from highly degraded to reasonably healthy, so it is clear that different approaches will be needed in the various river zones, with some problems requiring reach or even point scale solutions. Environmental flow needs have been determined through two major Expert Panel reports that identified the ecological priorities for the river. The next step is to translate these needs into feasible flow management actions that will provide the necessary hydrological conditions. Several investigations are underway to recommend options for flow management. Two important investigations are described in this paper: how to enhance flows to wetlands of national and international significance, and how to physically alter or change the operation of structures (including a dam, weir, lock, regulator, barrage or causeway), to provide significant environmental benefits. Early modelling suggests that the only option which has a positive environmental effect in all zones of the River is a reduction in overall water consumption.
25
Gatehouse, Robyn D., I. S. Williams e B. J. Pillans. "Fingerprinting windblown dust in south-eastern Australian soils by uranium-lead dating of detrital zircon". Soil Research 39, n.º 1 (2001): 7. http://dx.doi.org/10.1071/sr99078.
Texto completo da fonteResumo:
The U-Pb ages of fine-grained zircon separated from 2 dust-dominated soils in the eastern highlands of south-eastern Australia and measured by ion microprobe (SHRIMP) revealed a characteristic age ‘fingerprint’ from which the source of the dust has been determined and by which it will be possible to assess the contribution of dust to other soil profiles. The 2 soils are dominated by zircon 400–600 and 1000–1200 Ma old, derived from Palaeozoic granites and sediments of the Lachlan Fold Belt, but also contain significant components 100–300 Ma old, characteristic of igneous rocks in the New England Fold Belt in northern New South Wales and Queensland. This pattern closely matches that of sediments of the Murray-Darling Basin, especially the Mallee dunefield, suggesting that weathering of rocks in the eastern highlands has contributed large quantities of sediment to the arid and semi-arid inland basins via internally draining rivers of the present and past Murray–Darling River systems, where it has formed a major source of dust subsequently blown eastwards and deposited in the highland soils of eastern Australia.
26
Allan, Catherine, e Robyn J. Watts. "Framing Two Environmental Flow Trials in the Murray-Darling Basin, South-Eastern Australia". Water 14, n.º 3 (29 de janeiro de 2022): 411. http://dx.doi.org/10.3390/w14030411.
Texto completo da fonteResumo:
We make sense of the world around us through mental knowledge structures called ‘frames’. Frames, and the metaphors that help to form and maintain them, can be studied through examining discourse. In this paper, we aim to understand the framing of two trials with environmental water by analysing interview-derived discourse. Two separate flow trials, involving changes to river operating rules and practices, were undertaken in the Edward/Kolety-Wakool river system in Australia’s Murray-Darling Basin in 2017 and 2018, as part of the adaptive delivery of water for the environment. Semi-structured interviews with 18 actors in the Edward/Kolety-Wakool river system were undertaken in 2019, in which they reflected on the trials and the use of environmental water in the area. Analysis of the interviews suggest four framings of environmental water, which we have labelled business, engineering, science and medical. Each frame privileges expert practice, potentially marginalising other ways of experiencing and knowing the river system. ‘Participants’ in the social learning/adaptive management occurring in this situation, especially those with authority or influence, should be open to exploring alternate framings of situations. We present this small research project as a practical example of how a focus on revealing and considering discourse can provide interested actors with avenues for co-creation of new understandings and practice.
27
Mckenzie, DC, TS Abbott, KY Chan, PG Slavich e DJM Hall. "The nature, distribution and management of sodic soils in New-South-Wales". Soil Research 31, n.º 6 (1993): 839. http://dx.doi.org/10.1071/sr9930839.
Texto completo da fonteResumo:
Accurate data on the distribution of the various types of sodic soils in New South Wales are not available. However, general observations suggest that large areas are affected by structural instability as a result of sodicity, particularly on grey clays and red-brown earths of the Murray-Darling Basin. There is a strong need for new sodicity surveys because the production of crops and pasture often is well below potential on these lands. Exchangeable sodium data on their own do not adequately describe sodic soil behaviour, so information is also required about related factors such as electrical conductivity, exchangeable magnesium, clay mineralogy, pH, calcium carbonate content, degree of remoulding, and the frequency of continuous stable macropores. Critical limits for sodicity that are used by soil management advisory services need to be redefined. Considerable research into the reclamation and management of sodic soils has occurred in the irrigation areas and rainfed cropping districts of the Murray-Darling Basin in New South Wales. Mined and by-product gypsum, and to a lesser extent lime, have been shown to greatly improve the physical condition and profitability of production from soils with a dispersive surface. However, the responses to these treatments are less likely to be economical when sodicity is confined to the subsoil. Adequate supplies of gypsum and lime are available in New South Wales, but further research is required to determine economically optimal and environmentally acceptable rates and frequencies of application, particle sizes and chemical compositions for different farming systems that utilize the various types of sodic soil.
28
Jerry, Dean R. "Phylogeography of the freshwater catfish Tandanus tandanus (Plotosidae): a model species to understand evolution of the eastern Australian freshwater fish fauna". Marine and Freshwater Research 59, n.º 4 (2008): 351. http://dx.doi.org/10.1071/mf07187.
Texto completo da fonteResumo:
The geologically complex eastern Australian coastal margin supports the highest taxonomic diversity of freshwater fishes on the continent. However, mechanisms leading to coastal biogeographic patterns are poorly understood. A 399-bp fragment of the hypervariable mtDNA control region was sequenced from populations of eel-tailed catfish (Tandanus tandanus) to determine their phylogeographic structure and to relate this to proposed biogeographic mechanisms and landform evolution. Genetic structure in Tandanus is complex, with haplotypes clustering into three lineages: a phylogenetically distant, northern Queensland clade that is probably a new species; a mid-northern New South Wales clade corresponding to the recently discovered ‘Bellinger’ Tandanus cryptic species; and a third ‘derived’ clade T. tandanus. Phylogenetic analyses suggest that eastern Australian Tandanus originally invaded freshwaters from the coast where volcanic activity in the north and increasing aridity from the Paleocene reduced inter-fluvial connections, causing genetic divergence of northern Queensland and mid-northern New South Wales populations. The haplotypes represented by Murray–Darling drainage T. tandanus were the most derived, indicating that this species originally evolved on the coast and subsequently colonised the Murray–Darling basin. Tandanus in eastern Australia is phylogenetically structured and possibly comprises three species in this region; a pattern potentially shared by other eastern Australian freshwater fishes.
29
Koehn, John D., e D. J. Harrington. "Collection and distribution of the early life stages of the Murray cod (Maccullochella peelii peelii) in a regulated river". Australian Journal of Zoology 53, n.º 3 (2005): 137. http://dx.doi.org/10.1071/zo04086.
Texto completo da fonteResumo:
The Murray cod (Maccullochella peelii peelii) is a large fish species keenly sought by anglers. However, this species has declined in distribution and abundance and is now listed nationally as vulnerable. This study was undertaken in the Ovens and Murray rivers, to collect larvae and age-0 Murray cod and determine the distribution of larval Murray cod around the mid-Murray River irrigation storage of Lake Mulwala. Murray cod larvae were collected from 17 of 18 sites: main channels and flowing anabranch channels of regulated and unregulated rivers, sites upstream and downstream of the lake, in the upper and lower reaches of the lake, and in the outflowing Yarrawonga irrigation channel. Larval Murray cod were collected only by methods that sampled drift in flowing waters. Age-0 Murray cod were collected by electrofishing in the main river, but not in off-channel waters, suggesting that cod are likely to settle into habitats in the main channel at a post-larval stage. The widespread occurrence of drifting larvae suggests that this species may be subject to previously unrecognised threats as they pass through hydro-electric power stations or become stranded in anabranch and irrigation channels. Results of this study are likely to be applicable to other species with drifting larval stages, and are relevant to other locations in the Murray–Darling Basin.
30
Gonzalez, Dennis, Peter Dillon, Declan Page e Joanne Vanderzalm. "The Potential for Water Banking in Australia’s Murray–Darling Basin to Increase Drought Resilience". Water 12, n.º 10 (21 de outubro de 2020): 2936. http://dx.doi.org/10.3390/w12102936.
Texto completo da fonteResumo:
Banking water in aquifers during wet years for long-term storage then recovering it in drought is an application of managed aquifer recharge (MAR) that minimises evaporation losses. This requires a suitable aquifer for long-term storage of banked water and occasional periods when entitlements to surface water are available and affordable. This has been widely practised in Arizona and California but thus far not in Australia, in spite of severe impacts on agriculture, society, and the environment during recent droughts in the Murray–Darling Basin. This preliminary study based on a simple area exclusion analysis using six variables, some on a 90 m grid, over the 1 million km2 basin produced a first estimate of the order of 2–4 × 109 m3 of additional aquifer storage potential in surficial aquifers close to rivers. For 6 of the 23 catchments evaluated, banking capacity exceeded an average water depth of 0.3 m for the irrigated area. At one prospective site in the Macquarie River catchment in New South Wales, water banking operations at various scales were simulated using 55 years of historical monthly hydrologic data, with recharge and recovery triggered by dam storage levels. This showed that the estimated 300 × 106 m3 additional local aquifer capacity could be fully utilised with a recharge and recovery capacity of 6 × 106 m3/month, and recharge occurred in 67% of months and recovery in 7% of months. A novel simulation of water banking with recharge and recovery triggered by water trading prices using 11 years of data gave a benefit cost ratio of ≈ 2. Data showed that water availability for recharge was a tighter constraint on water banking than aquifer storage capacity at this location. The analysis reveals that water banking merits further consideration in the Murray–Darling Basin. Firstly, management across hydrologically connected systems requires accounting for surface water and groundwater entitlements and allocations at the appropriate scale, as well as developing equitable economic and regulatory arrangements. Of course, site-specific assessment of water availability and hydrogeological suitability would be needed prior to construction of demonstration projects to support full-scale implementation.
31
Humpage, AR, J. Rositano, AH Bretag, R. Brown, PD Baker, BC Nicholson e DA Steffensen. "Paralytic shellfish poisons from Australian cyanobacterial blooms". Marine and Freshwater Research 45, n.º 5 (1994): 761. http://dx.doi.org/10.1071/mf9940761.
Texto completo da fonteResumo:
Saxitoxin-group neurotoxins (paralytic shellfish poisons) have been identified in a cultured strain of Anabaena circinalis and in natural bloom samples in which this species was the dominant organism collected from widely distributed sites in the Murray-Darling Basin of Australia. These toxins have hitherto been isolated almost exclusively from 'red tide' dinoflagellates and contaminated shellfish. Two 'aphantoxins', which appear to be identical to two of the paralytic shellfish poisons, have been identified in a cyanobacterium from a small number of sites in New Hampshire, USA. The conclusions are supported by electrophysiological studies and by high-performance liquid chromatographic (HPLC) and fast atom bombardment-mass spectrometric (FAB-MS) analyses.
32
Sluiter, Ian R. K., Andrew Schweitzer e Ralph Mac Nally. "Spinifex–mallee revegetation: implications for restoration after mineral-sands mining in the Murray–Darling Basin". Australian Journal of Botany 64, n.º 6 (2016): 547. http://dx.doi.org/10.1071/bt15265.
Texto completo da fonteResumo:
Mineral-sands mining in the semiarid and arid zone of south-eastern Australia is now a widespread disturbance that may adversely affect large areas of remnant vegetation, including mallee (Eucalyptus spp.) with hummock grass or spinifex (Triodia scariosa) understorey. No broad-scale restoration projects have been undertaken to revegetate mallee Eucalyptus species with spinifex. We report on the survivorship and relative importance (spatial coverage) of hand-planted tubestock 10 years after establishment in 2001, which included mallee Eucalyptus, Triodia scariosa, Acacia spp. and Hakea spp. These taxa are the dominant plants in a semiarid dune–swale system on a former mineral-sands mine licence area in semiarid, north-western Victoria. Mean survivorship of tubestock was 0.58 ± 0.04. Spinifex (Triodia scariosa), needlewood (Hakea) and several mallee species (Eucalyptus spp.) survived substantially better than the average of all tubestock-planted species, although Acacia spp. had low survivorships. Although the plantings were undertaken in the early stages of the most severe drought in the instrumental record (the ‘Millennium drought’), several taxa survived well and species such as spinifex established and developed ground coverage greater than the benchmark values for the ecological vegetation class of the location. We conclude that hand-planting of tubestock can achieve restoration objectives for this component of spinifex–mallee vegetation, even under extremely arduous conditions associated with long-term drought. We also herald the importance of taking a long-term view to the assessment of revegetation success, in this case 10 years.
33
Herczeg, A. L., S. S. Dogramaci e F. W. J. Leaney. "Origin of dissolved salts in a large, semi-arid groundwater system: Murray Basin, Australia". Marine and Freshwater Research 52, n.º 1 (2001): 41. http://dx.doi.org/10.1071/mf00040.
Texto completo da fonteResumo:
Hypotheses to explain the source of the 1011 tons of salt in groundwaters of the Murray Basin, south-eastern Australia, are evaluated; these are (a) mixing with original sea water, (b) dissolution of salt deposits, (c) weathering of aquifer minerals and (d) acquisition of solutes via rainfall. The total salinity and chemistry of many groundwater samples are similar to sea-water composition. However, their stable isotopic compositions (δ18O= –6.5 ‰; δ2H = –35) are typical of mean winter rainfall, indicating that all the original sea water has been flushed out of the aquifer. Br/Cl mass ratios are approximately the same as sea water (3.57 x 10-3) indicating that NaCl evaporites (which have Br/Cl<10-4) are not a significant contributor to Cl in the groundwater. Similarly, very low abundances of Cl in aquifer minerals preclude rock weathering as a significant source of Cl. About 1.5 million tons of new salt is deposited in the Murray–Darling Basin each year by rainfall.The groundwater chemistry has evolved by a combination of atmospheric fallout of marine and continentally derived solutes and removal of water by evapo-transpiration over tens of thousands of years of relative aridity. Carbonate dissolution/precipitation, cation exchange and reconstitution of secondary clay minerals in the aquifers results in a groundwater chemistry that retains a ‘sea-water-like’ character.
34
Crimp, S. J., C. J. Stokes, S. M. Howden, A. D. Moore, B. Jacobs, P. R. Brown, A. J. Ash, P. Kokic e P. Leith. "Managing Murray–Darling Basin livestock systems in a variable and changing climate: challenges and opportunities". Rangeland Journal 32, n.º 3 (2010): 293. http://dx.doi.org/10.1071/rj10039.
Texto completo da fonteResumo:
The key biophysical impacts associated with projected climate change in the Murray–Darling Basin (MDB) include: declines in pasture productivity, reduced forage quality, livestock heat stress, greater problems with some pests and weeds, more frequent droughts, more intense rainfall events, and greater risks of soil degradation. The most arid and least productive rangelands in the MDB region may be the most severely impacted by climate change, while the more productive eastern and northern grazing lands in the MDB may provide some opportunities for slight increases in production. In order to continue to thrive in the future, livestock industries need to anticipate these changes, prepare for uncertainty, and develop adaptation strategies now. While climate change will have direct effects on livestock, the dominant influences on grazing enterprises in the MDB will be through changes in plant growth and the timing, quantity and quality of forage availability. Climate change will involve a complex mix of responses to rising atmospheric carbon dioxide levels, rising temperatures, changes in rainfall and other weather factors, and broader issues related to how people collectively and individually respond to these changes. Enhancing the ability of individuals to respond to a changing climate will occur through building adaptive capacity. We have, via secondary data, selected from the Australian Agricultural and Grazing Industries Survey, built a national composite index of generic adaptive capacity of rural households. This approach expresses adaptive capacity as an emergent property of the diverse forms of human, social, natural, physical and financial capital from which livelihoods are derived. Human capital was rated as ‘high’ across the majority of the MDB compared with the rest of Australia, while social, physical and financial capital were rated as ‘moderate’ to ‘low’. The resultant measure of adaptive capacity, made up of the five capitals, was ‘low’ in the northern and central-west regions of the MDB and higher in the central and eastern parts possibly indicating a greater propensity to adapt to climate change in these regions.
35
Garrick, Dustin, Lucia De Stefano, Fai Fung, Jamie Pittock, Edella Schlager, Mark New e Daniel Connell. "Managing hydroclimatic risks in federal rivers: a diagnostic assessment". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 371, n.º 2002 (13 de novembro de 2013): 20120415. http://dx.doi.org/10.1098/rsta.2012.0415.
Texto completo da fonteResumo:
Hydroclimatic risks and adaptive capacity are not distributed evenly in large river basins of federal countries, where authority is divided across national and territorial governments. Transboundary river basins are a major test of federal systems of governance because key management roles exist at all levels. This paper examines the evolution and design of interstate water allocation institutions in semi-arid federal rivers prone to drought extremes, climatic variability and intensified competition for scarce water. We conceptualize, categorize and compare federal rivers as social–ecological systems to analyse the relationship between governance arrangements and hydroclimatic risks. A diagnostic approach is used to map over 300 federal rivers and classify the hydroclimatic risks of three semi-arid federal rivers with a long history of interstate allocation tensions: the Colorado River (USA/Mexico), Ebro River (Spain) and Murray–Darling River (Australia). Case studies review the evolution and design of water allocation institutions. Three institutional design trends have emerged: adoption of proportional interstate allocation rules; emergence of multi-layered river basin governance arrangements for planning, conflict resolution and joint monitoring; and new flexibility to adjust historic allocation patterns. Proportional allocation rules apportion water between states based on a share of available water, not a fixed volume or priority. Interstate allocation reform efforts in the Colorado and Murray–Darling rivers indicate that proportional allocation rules are prevalent for upstream states, while downstream states seek reliable deliveries of fixed volumes to increase water security. River basin governance arrangements establish new venues for multilayered planning, monitoring and conflict resolution to balance self governance by users and states with basin-wide coordination. Flexibility to adjust historic allocation agreements, without risk of defection or costly court action, also provides adaptive capacity to manage climatic variability and shifting values. Future research should develop evidence about pathways to adaptive capacity in different classes of federal rivers, while acknowledging limits to transferability and the need for context-sensitive design.
36
Anderson, JR, AK Morison e DJ Ray. "Age and growth of Murray Cod, Maccullochella peelii (Perciformes: Percichthyidae), in the Lower Murray-Darling Basin, Australia, from thin-sectioned Otoliths". Marine and Freshwater Research 43, n.º 5 (1992): 983. http://dx.doi.org/10.1071/mf9920983.
Texto completo da fonteResumo:
Transverse thin sections (0.5 mm thick) of sagittal otoliths from 290 Murray cod up to 1400 mm in total length and 47.3 kg in weight were used to establish the age and growth of cod in the lower Murray-Darling Basin, including comparisons of recent (1986-91) and past (1949-51) growth rates and growth in different waters. The maximum estimated age was 48 years. Quantitative and qualitative analysis of the seasonal changes in otolith marginal increments showed that annuli in fish of all ages were laid down each spring, and 1 October was assigned as the birthday. The thin-sectioning method was validated by comparing age estimates for 55 Murray cod from Lake Charlegrark (age 0-21 years), which had been validated by using burnt and polished half-otoliths. The new method had an accuracy of 96.4% and it offers major advantages in ease of preparation, reading, and batch-handling of large numbers of otoliths. The precision of the method, estimated as an average error for four readers, was 5.4% (3.0% after ignoring discrepancies in relation to annuli on otolith edges). There was a linear relationship between otolith weight and fish age and an exponential relationship between otolith weight and fish length. Both otolith length and otolith width reached an asymptote at about 15 years, when fish length also approached its maximum. However, otolith thickness continued to increase throughout the life of the fish and, after about 15 years, contributed most to the increase in otolith weight. This confirmed that otoliths continued to grow in thickness and that annuli were laid down throughout life, and that cod could be aged reliably to the maximum age. The annulus pattern is very clear and distinct, and the reading techniques are fully described, including recognition of 'larval' and 'false' rings. Various differences were found in the growth rates, and the length-weight relationships for males and females, for cod caught in 1986-91 and those caught in 1949-51, and various subpopulations are discussed. The von Bertalanffy growth parameters (all individuals combined) were estimated at L∞ = 1202 mm, k=0.108 and t0= -0.832. The availability of a reliable ageing method provides the first opportunity to determine year of birth and thus to examine the age structure of populations and to effectively manage cod populations that have declined in abundance.
37
Watkins, Susanne C., G. P. Quinn e Ben Gawne. "Changes in organic-matter dynamics and physicochemistry, associated with riparian vegetation loss and river regulation in floodplain wetlands of the Murray River, Australia". Marine and Freshwater Research 61, n.º 10 (2010): 1207. http://dx.doi.org/10.1071/mf09312.
Texto completo da fonteResumo:
Extensive clearing of floodplain forests potentially reduces organic matter available to floodplain wetlands. Furthermore, on rivers regulated to provide irrigation water in summer, floodplain wetlands that were previously inundated in spring, now flood in summer/autumn. In the Murray–Darling Basin, Australia, this has changed the timing of organic matter entering the aquatic phase, since leaf fall peaks in summer. Field surveys and mesocosm experiments on floodplain wetlands on the River Murray revealed faster processing rates of leaves in summer/autumn than spring, and no difference between cleared and forested wetlands. Temperature and leaf carbon : nitrogen ratio could not explain these differences, and instead, changes to leaf chemistry associated with ‘terrestrial ageing’ between peak leaf fall in summer and inundation in spring is more likely. The results indicated that the reduction of input of organic matter through riparian tree clearing and changing the timing of inundation interact to alter organic-matter standing stocks and rates of decomposition in floodplain wetlands. Restoring both natural timing of high flows and riparian vegetation might be required for recovery of these wetlands.
38
Hammer, Michael P., Mark Adams, Peter J. Unmack e Keith F. Walker. "A rethink on Retropinna: conservation implications of new taxa and significant genetic sub-structure in Australian smelts (Pisces:Retropinnidae)". Marine and Freshwater Research 58, n.º 4 (2007): 327. http://dx.doi.org/10.1071/mf05258.
Texto completo da fonteResumo:
The smelt genus Retropinna nominally includes three small (<150 mm) freshwater fish species endemic to south-eastern Australia and New Zealand. For the two Australian species, the broad range of R. semoni (Weber) on the mainland suggests some vulnerability to isolation and genetic divergence, whereas the apparent confinement of R. tasmanica McCulloch to Tasmania is curious if, as suspected, it is anadromous. Analyses of Australian material using allozyme electrophoresis show five genetically distinct species with contiguous ranges and no evidence of genetic exchange. Three occur along the eastern seaboard (including three instances of sympatry), another in coastal and inland south-eastern Australia and Tasmania, and a fifth species in the Lake Eyre Basin. There is no indication of a simple ‘tasmanica’ v. ‘semoni’ dichotomy, but instead a complex pattern involving discrete clusters for the Upper Murray plus Darling rivers, Lower Murray, Glenelg River and Tasmanian regions, with coastal western Victorian samples having varying affinity to these groups. The overall pattern is one of deep divergences among species and strong genetic sub-structuring within and provides a strong argument for extended studies to prepare for appropriate conservation measures.
39
Kirby, Mac, Jeff Connor, Mobin-ud Din Ahmad, Lei Gao e Mohammed Mainuddin. "Irrigator and Environmental Water Management Adaptation to Climate Change and Water Reallocation in the Murray–Darling Basin". Water Economics and Policy 01, n.º 03 (setembro de 2015): 1550009. http://dx.doi.org/10.1142/s2382624x15500095.
Texto completo da fonteResumo:
In an earlier paper (Kirby et al. 2014a), we showed that climate change and a new policy which reallocates water to the environment will impact both the flow of water and the income derived from irrigation in the Murray–Darling Basin. Here, we extend the analysis to consider irrigator and environmental water management strategies to adapt to these new circumstances. Using an integrated hydrology-economics model, we examine a range of strategies and their impact on flows and the gross income of irrigation. We show that the adaptation strategies provide a range of flow and economic outcomes in the Basin. Several strategies offer significant scope to enhance flows without large adverse impacts on the gross income of irrigation overall. Some environmental water management strategies enhance flows in the Murray part of the basin even under the drying influence of a projected median climate change. Irrigator strategies that include carryover of water in storage from one year to the next provide for lesser year to year variability in gross income and may be regarded as more advantageous in providing security against droughts. Flows and the gross income of low value irrigation industries strategies are sensitive to climate change, irrespective of adaptation strategy. Should a projected dry extreme climate change be realized, no strategy can prevent a large reduction in flows and also in gross income, particularly of low value irrigation industries. Nevertheless, environmental water management strategies mitigate the impact on flows, and in some cases may also help mitigate the impacts on gross income. High value irrigation industries are less affected (in terms of gross income, though net income will reduce because of rising water prices) by projected climate change, consistent with observation in the recent long term drought.
40
Haensch, Juliane, Sarah Ann Wheeler, Alec Zuo e Henning Bjornlund. "The Impact of Water and Soil Salinity on Water Market Trading in the Southern Murray–Darling Basin". Water Economics and Policy 02, n.º 01 (março de 2016): 1650004. http://dx.doi.org/10.1142/s2382624x16500041.
Texto completo da fonteResumo:
Irrigators in the Murray–Darling Basin (MDB) of Australia face a salinity triple threat, namely: dryland salinity, surface-water, and groundwater salinity. Water trading has now been adopted to the point where it is a common adaptation tool used by the majority of irrigators in the Basin. This study uses a number of unique water market and spatial databases to investigate the association between the severity and extent of areas which suffer from salinity and permanent trade over time, holding other regional characteristics constant. It was found that larger volumes of permanent water were likely to be sold from areas suffering from higher dryland salinity. In addition, increases in the concentration of groundwater salinity was found to decrease volumes of surface-water entitlements sold, providing evidence that groundwater entitlements (where they are viable substitutes) have been increasingly used as substitutes for surface-water entitlements in recent years. Other key influences on water sales included water market prices and net rainfall.
41
Bjornlund, Henning. "Irrigators and the new policy paradigm – An Australian case study". Water Policy 7, n.º 6 (1 de dezembro de 2005): 581–95. http://dx.doi.org/10.2166/wp.2005.0035.
Texto completo da fonteResumo:
The new water policy paradigm has been vigorously implemented and pursued in Australia since the early 1990s. This paper analyses how elements of this new paradigm have been adopted and perceived by irrigators within two different states of the Murray-Darling Basin in south eastern Australia and how these policies have had an impact on the lives and aspirations of farming families. The analyses are based on 700 telephone interviews with irrigators who have bought and sold water on the markets for temporary or permanent water as well as irrigators who have never traded. The analyses suggest that the impact and perception of the new policy instruments are not primarily delineated between buyers and sellers in the water market as could have been expected, but by the irrigators' position in the adjustment process, which determines how the irrigators are active in the water market.
42
Vanags, C. P., e R. W. Vervoort. "Hydrological and water-use efficiency implications of geomorphological stratification in palæochannels in the Northern Murray–Darling Basin". Crop and Pasture Science 64, n.º 12 (2013): 1182. http://dx.doi.org/10.1071/cp13168.
Texto completo da fonteResumo:
Regional climactic variability coupled with an increasing demand on water has placed an even greater pressure on managers to understand the complex relationships between surface water and groundwater in the Murray–Darling Basin. Based on limited soil sampling combined with geophysical observations, past research has suggested that relic subsurface drainage features (also known as palæochannels) have a higher risk of deep drainage and lateral flow, particularly where water is impounded or applied as irrigation. The aim of this study was to investigate the hydrological behaviour of an irrigated 25-ha site in North-western New South Wales in more detail to predict deep drainage risk in the presence of palæochannel systems. Several years of direct and indirect observations, including soil sampling and groundwater measures, were collected. Coupling the field data with one- and two-dimensional water balance models revealed a more complex behaviour where a palæochannel functions like a large underground drain. In contrast to other studies, this study suggests that the actual palæochannel does not pose a higher drainage risk, but the combination of the palæochannels with the surroundings soils does have a higher deep drainage risk.
43
Nock, Catherine J., Martin S. Elphinstone, Stuart J. Rowland e Peter R. Baverstock. "Phylogenetics and revised taxonomy of the Australian freshwater cod genus, Maccullochella (Percichthyidae)". Marine and Freshwater Research 61, n.º 9 (2010): 980. http://dx.doi.org/10.1071/mf09145.
Texto completo da fonteResumo:
Determining the phylogenetic and taxonomic relationships among allopatric populations can be difficult, especially when divergence is recent and morphology is conserved. We used mitochondrial sequence data from the control region and three protein-coding genes (1253 bp in total) and genotypes determined at 13 microsatellite loci to examine the evolutionary relationships among Australia’s largest freshwater fish, the Murray cod, Maccullochella peelii peelii, from the inland Murray–Darling Basin, and its allopatric sister taxa from coastal drainages, the eastern freshwater cod, M. ikei, and Mary River cod, M. peelii mariensis. Phylogenetic analyses provided strong support for taxon-specific clades, with a clade containing both of the eastern taxa reciprocally monophyletic to M. peelii peelii, suggesting a more recent common ancestry between M. ikei and M. peelii mariensis than between the M. peelii subspecies. This finding conflicts with the existing taxonomy and suggests that ancestral Maccullochella crossed the Great Dividing Range in the Pleistocene and subsequently diverged in eastern coastal drainages. Evidence from the present study, in combination with previous morphological and allozymatic data, demonstrates that all extant taxa are genetically and morphologically distinct. The taxonomy of Maccullochella is revised, with Mary River cod now recognised as a species, Maccullochella mariensis, a sister species to eastern freshwater cod, M. ikei. As a result of the taxonomic revision, Murray cod is M. peelii.
44
Gell, Peter A., Sorell Bulpin, Peter Wallbrink, Gary Hancock e Sophie Bickford. "Tareena Billabong - a palaeolimnological history of an ever-changing wetland, Chowilla Floodplain, lower Murray - Darling Basin, Australia". Marine and Freshwater Research 56, n.º 4 (2005): 441. http://dx.doi.org/10.1071/mf04107.
Texto completo da fonteResumo:
A 427-cm sediment core was extracted from Tareena Billabong, a Murray River floodplain wetland in the extreme south-west of New South Wales, Australia. Analysis of fossil diatoms and pollen, sediment 210Pb and 137Cs profiles and radiocarbon and luminescence dating reveal that Tareena Billabong has undergone substantial environmental change in its ~5000-year history. Shortly after its formation, the billabong was a freshwater lagoon with a diatom flora dominated by Synedra ulna and Planothidium lanceolatum. An increase in Aulacoseira granulata, a river plankton dominant today, reflects two phases of increased connectivity with the Murray River in the mid to late Holocene. A shift to lagoonal taxa after ~3000 years BP is attributed to water balance and river-flow changes, possibly associated with regional climate change. Importantly, it appears to have undergone an extended phase of increasing turbidity, and possibly wetland salinity, commencing ~3000 years BP. Sedimentation increased at least 15-fold in the European phase. Billabong salinity increased markedly soon after European settlement, reaching a peak in the late 1800s AD. While regulation then increased the degree of connection between the billabong with the River in the 1920s AD, salinity levels remained high. Increased salinity is revealed by increases in the diatom taxa Amphora spp., Cyclotella meneghiniana, Gyrosigma acuminatum, Planothidium delicatulum and Tryblionella hungarica and by declines in Casuarinaceae, Eucalyptus, Myriophyllum and Cyperaceae pollen. Tareena Billabong was subjected to considerable environmental pressures from the early stages of European settlement in terms of sediment load, hydrological change and salinity.
45
Connell, Daniel. "Arguing the Case to Include a Wider Range of Stakeholders in the Murray–Darling Basin Policy Process". Water Economics and Policy 03, n.º 03 (29 de dezembro de 2016): 1650040. http://dx.doi.org/10.1142/s2382624x16500405.
Texto completo da fonteResumo:
Implementation of water reform in the Murray–Darling Basin has stalled. The principles remain in legislation, but government priorities are increasingly focused on irrigation-based agriculture rather than the comprehensive range of stakeholders with a legitimate interest in decisions about the future of the MDB. The negotiations required to gain parliamentary approval of the MDB Basin Plan in 2012 resulted in extensive concessions. Some have seriously damaged its integrity as a reform package. Within this now fragmented policy framework, the utility of important individual components has been eroded. These include acceptance of the need for a comprehensive analytical framework able to take full account of costs and benefits, the precautionary principle, the beneficiary pays principle, consistent policies for assigning public benefit from public investment, the importance of a comprehensive whole-of-catchment framework for managing social and biophysical processes and the understanding that serious water reform requires change in the cultural values related to the water-human relationship. As a result of these compromises, the capacity of the Basin Plan framework to manage future climate change challenges and development pressures is in doubt. Can this trend be reversed? The paper argues for a revitalization of the public policy process to bring in a wider range of stakeholders and expose decision making to more rigorous assessment. To help achieve this goal, control over a substantial proportion of the environmental water entitlements acquired by the national government should be devolved to elected regional bodies (who would have to work within auditing guidelines). This would stimulate community involvement by providing a substantial activity that would make engagement worthwhile.
46
Llewellyn, L. "Observations on the breeding biology ofAmbassis agassiziiSteindachner, 1867 (Teleostei: Ambassidae) from the Murray Darling Basin in New South Wales". Australian Zoologist 34, n.º 4 (janeiro de 2008): 476–98. http://dx.doi.org/10.7882/az.2008.026.
Texto completo da fonte
47
Briscoe, John. "The Harvard Water Federalism Project – process and substance". Water Policy 16, S1 (1 de março de 2014): 1–10. http://dx.doi.org/10.2166/wp.2014.001.
Texto completo da fonteResumo:
This Special Edition of Water Policy is one outcome of an innovative educational and research project, the Harvard Water Federalism Project, designed to train a new generation of students from a wide variety of disciplines to address the growing challenge of water security. This paper describes the core ideas behind the project, namely the creation of a new generation of ‘specialized integrators’ and that of exposing students to the wisdom of ‘thinking practitioners’. The paper describes the particular water problem chosen, namely that of the infrastructural and institutional challenges involved with the development and management of water in large rivers (the Colorado, Indus, Mississippi, Murray–Darling and São Francisco) in federal countries (Australia, Brazil, Pakistan and the United States). The paper serves as an overview to the basin papers written by multi-disciplinary student teams, and draws some general lessons from this comparative analysis.
48
ROGERS, D. CHRISTOPHER, BRIAN V. TIMMS, MERLIJN JOCQUÈ e LUC BRENDONCK. "A new genus and species of branchipodid fairy shrimp (Crustacea: Branchiopoda: Anostraca) from Australia". Zootaxa 1551, n.º 1 (15 de agosto de 2007): 49–59. http://dx.doi.org/10.11646/zootaxa.1551.1.3.
Texto completo da fonteResumo:
A new anostracan genus with two new species in the family Branchipodidae is described from the Murray Darling basin, Australia. This is the first record of the family from Australia. Males of Australobranchipus typically have long and elaborate frontal appendages comparable to those in the branchipodid genera Branchipus and Pumilibranchipus. Females have a compact brood pouch like other branchipodid genera. Two new species in this genus are described (A. parooensis and A. gilgaiphila). Along with recent additions in Branchinella and Parartemia, and confirmation of the presence of Streptocephalus, these new findings change the concept of low diversity among higher anostracan taxa in Australia. Australobranchipus is also remarkable for having the shortest known life cycle of any Australian anostracans. In the type locality, which typically holds water for only two to six weeks in occasional years, and when cultured, it matures within a week and dies within two weeks, allowing these species to avoid competition with other anostracans.
49
Gabbrielli, E. "The use of modelling and reuse techniques in the development of water management systems in basins with limited water resources". Water Science and Technology 49, n.º 7 (1 de abril de 2004): 33–38. http://dx.doi.org/10.2166/wst.2004.0409.
Texto completo da fonteResumo:
Drawing on experiences in New South Wales from 1950 to 1980 in modeling and re-use techniques in the development of desalination technology and its application in fresh water production for potable use, the paper describes how Australia realized its responsibilities in developing participative and sustainable approaches to land use and water resources management. An analysis of the lessons from the operation of the Bayswater zero-discharge power station significantly contributed to the debate on sustainable approaches, highlighting that no management policy of a water basin can be implemented without a model based on reliable data from all sectors (including the environment), and no management model can be implemented without the participation of all stakeholders. These ideals were reflected in the conception and establishment of the Murray-Darling Basin Commission. The Commission succeeded in bringing together all major stakeholders in this huge basin, though it took more than 15 years to do so. While widely recognized as one of the most advanced and successful experiences in integrated management of a drainage basin, it has still not achieved the reversal of many unsustainable agricultural practices, giving a clear indication of the difficulties and time required for producing sustainable solutions.
50
Callaghan, Jeff. "A comparison of weather systems in 1870 and 1956 leading to extreme floods in the Murray–Darling Basin". Journal of Southern Hemisphere Earth Systems Science 69, n.º 1 (2019): 84. http://dx.doi.org/10.1071/es19003.
Texto completo da fonteResumo:
This research is the extension of a project studying the impact of 19th century severe weather events in Australia and their relation to similar events during the 20th and 21st century. Two floods with the worst known impacts in the Murray–Darling Basin (MDB) are studied. One of these events which occurred during 1956 is relativelywell known and the Bureau of Meteorology archives contain good rainfall data covering the period. Additionally, information on the weather systems causing this rainfall can be obtained. Rainfall, flood and weather system data for this event are presented here and compared with a devastating event during 1870. Although archived Australian rainfall data is negligible during 1870 and there is no record of weather systems affecting Australia during that year, a realistic history of the floods and weather systems in the MDB during 1870 is created. This follows an extensive search through newspaper archives contained in the National Library of Australia’s web site. Examples are presented showing how the meteorological data in 19th century newspapers can be used to create weather charts. Six such events in 1870 are demonstrated and three of these had a phenomenal effect on the Murray–Darling system. The 1870 floods followed drought type conditions and it is remarkable that it was worse in many ways than the 1956 event which followed flood conditions in the MDB during the previous year. The events in 1870 caused much loss of life from drowning in the MDB in particular froman east coast low (ECL) in April 1870 and two Victorian weather systems in September and October 1870. In 1956, there were also record-breaking events especially during March when all-time record monthly rainfall were reported in New South Wales. Overall the greatest impact from flooding across the whole MDB was associated with the 1870 flooding. Analyses of heavy rainfall areas in the MDB showed a linear trend increase from 1900 to 2018. Analysing the same data using an 8-year moving average highlighted three peaks around the five highest annual rainfall years. The largest peak occurred around 1950 and 1956, the second largest around 1973 and 1974 and the third around 2010. Each of these 5 years occurred during negative phases of the Interdecadal Pacific Oscillation (IPO) and positive phases of the Southern Oscillation Index (SOI). Studies have shown that the SOI is a climate driver in the MDB along with a persistent blocking high-pressure systems south of Australia along longitude 140°E with a low to its north. Three major blocking events with record rainfall and flooding in the MDB occurred in 1983, 1984 and 1990. Thiswas during the period 1977–1990 when blocking was conducive to heavy rain in the MDB and was coincidentwith a positive phase of the IPO, thus helping conflictwith the IPO–MDB heavy rainfall relationship. Persistent and unexplained middle level westerly winds kept subtropical Queensland clear of tropical cyclones during the negative phases of the IPO from 1999 to 2009 and during the 1960s, influencing low rainfall in the MDB during those periods.