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1
Fülöp, R. H., A. T. Codilean, K. M. Wilcken, T. J. Cohen, D. Fink, A. M. Smith, B. Yang et al. "Million-year lag times in a post-orogenic sediment conveyor". Science Advances 6, n. 25 (giugno 2020): eaaz8845. http://dx.doi.org/10.1126/sciadv.aaz8845.
Testo completoAbstract (sommario):
Understanding how sediment transport and storage will delay, attenuate, and even erase the erosional signal of tectonic and climatic forcings has bearing on our ability to read and interpret the geologic record effectively. Here, we estimate sediment transit times in Australia’s largest river system, the Murray-Darling basin, by measuring downstream changes in cosmogenic 26Al/10Be/14C ratios in modern river sediment. Results show that the sediments have experienced multiple episodes of burial and reexposure, with cumulative lag times exceeding 1 Ma in the downstream reaches of the Murray and Darling rivers. Combined with low sediment supply rates and old sediment blanketing the landscape, we posit that sediment recycling in the Murray-Darling is an important and ongoing process that will substantially delay and alter signals of external environmental forcing transmitted from the sediment’s hinterland.
2
Maini, N., A. Buchan e S. Joseph. "Derivation of a salinity target for the Lower Murray Darling Valley". Water Science and Technology 48, n. 7 (1 ottobre 2003): 105–12. http://dx.doi.org/10.2166/wst.2003.0430.
Testo completoAbstract (sommario):
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.
3
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. 6 (2019): 857. http://dx.doi.org/10.1071/mf18347.
Testo completoAbstract (sommario):
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.
4
Davie, Alec W., e Joe B. Pera. "The Fish Health Risk Indicator: linking water quality and river flow data with fish health to improve our predictive capacity around fish death events". Marine and Freshwater Research 73, n. 2 (2022): 193. http://dx.doi.org/10.1071/mf20360.
Testo completoAbstract (sommario):
Severe drought conditions contributed to three mass fish mortality events in the Darling River near Menindee, part of the Murray–Darling Basin, Australia, during the summer of 2018–19. An independent assessment recommended the need for improved modelling approaches to identify when sections of rivers may be more susceptible to fish kill events. We present a geographic information system (GIS)-based tool that combines meteorological forecasts with river flow and algal biomass datasets to identify river reaches where additional stresses on fish health may produce an increased risk of mass fish deaths. At present the tool is still in development and will require the addition of extra datasets and testing using historical datasets to further validate its accuracy. Despite the tool being in its development stage, the decision support tool has been widely accepted and provides natural resource managers with a rapid way to understand and communicate risks to fish health, supporting improved water management options across the Murray–Darling Basin that may ultimately help reduce the frequency and severity of large-scale fish mortality events.
5
Pittock, Jamie, e C. Max Finlayson. "Australia's Murray - Darling Basin: freshwater ecosystem conservation options in an era of climate change". Marine and Freshwater Research 62, n. 3 (2011): 232. http://dx.doi.org/10.1071/mf09319.
Testo completoAbstract (sommario):
River flows in the Murray–Darling Basin, as in many regions in the world, are vulnerable to climate change, anticipated to exacerbate current, substantial losses of freshwater biodiversity. Additional declines in water quantity and quality will have an adverse impact on existing freshwater ecosystems. We critique current river-management programs, including the proposed 2011 Basin Plan for Australia’s Murray–Darling Basin, focusing primarily on implementing environmental flows. River management programs generally ignore other important conservation and adaptation measures, such as strategically located freshwater-protected areas. Whereas most river-basin restoration techniques help build resilience of freshwater ecosystems to climate change impacts, different measures to enhance resilience and reoperate water infrastructure are also required, depending on the degree of disturbance of particular rivers on a spectrum from free-flowing to highly regulated. A crucial step is the conservation of free-flowing river ecosystems where maintenance of ecological processes enhances their capacity to resist climate change impacts, and where adaptation may be maximised. Systematic alteration of the operation of existing water infrastructure may also counter major climate impacts on regulated rivers.
6
Sheldon, Fran, e Keith F. Walker. "Spatial distribution of littoral invertebrates in the lower Murray - Darling River system, Australia". Marine and Freshwater Research 49, n. 2 (1998): 171. http://dx.doi.org/10.1071/mf96062.
Testo completoAbstract (sommario):
The abundance and richness of macroinvertebrates in the lower Murray and Darling rivers were examined at a macroscale (rivers), mesoscale (billabongs, backwaters, channel) and microscale (vegetation, snags, substrata). In the Darling, insects dominated (85% of taxa, 81% of individuals); the richest taxa were Diptera (26 taxa) and Coleoptera (15 taxa) and the most abundant were Hemiptera (47%) and Diptera (35%). In the Murray, insects again dominated (84% of taxa, 52% of individuals), particularly Diptera (22 taxa), Coleoptera (12 taxa) and Hemiptera (9 taxa), but there were more crustaceans (9% of taxa, 47% of individuals, particularly the atyid shrimp Paratya australiensis). Both assemblages were uneven: in the Darling, >50% of biomass was Micronecta spp. (Corixidae), Dicrotendipes sp. (Chironomidae) and Macrobrachium australiense (Palaemonidae); in the Murray, 70% of biomass was P. australiensis and Caridina mccullochi (Atyidae) and the insects Micronecta spp. (Corixidae) and Chironomus sp. (Chironomidae). Abundances generally were greatest in the Murray. Hydrologic and geomorphic factors influenced assemblages at the macroscale, whereas microhabitat diversity dominated at the mesoscale.
7
Draper, Clara, e Graham Mills. "The Atmospheric Water Balance over the Semiarid Murray–Darling River Basin". Journal of Hydrometeorology 9, n. 3 (1 giugno 2008): 521–34. http://dx.doi.org/10.1175/2007jhm889.1.
Testo completoAbstract (sommario):
Abstract The atmospheric water balance over the semiarid Murray–Darling River basin in southeast Australia is analyzed based on a consecutive series of 3- to 24-h NWP forecasts from the Australian Bureau of Meteorology’s Limited Area Prediction System (LAPS). Investigation of the LAPS atmospheric water balance, including comparison of the forecast precipitation to analyzed rain gauge observations, indicates that the LAPS forecasts capture the general qualitative features of the water balance. The key features of the atmospheric water balance over the Murray–Darling Basin are small atmospheric moisture flux divergence (at daily to annual time scales) and extended periods during which the atmospheric water balance terms are largely inactive, with the exception of evaporation, which is consistent and very large in summer. These features present unique challenges for NWP modeling. For example, the small moisture fluxes in the basin can easily be obscured by the systematic errors inherent in all NWP models. For the LAPS model forecasts, there is an unrealistically large evaporation excess over precipitation (associated with a positive bias in evaporation) and unexpected behavior in the moisture flux divergence. Two global reanalysis products (the NCEP Reanalysis I and the 40-yr ECMWF Re-Analysis) also both describe (physically unrealistic) long-term negative surface water budgets over the Murray–Darling Basin, suggesting that the surface water budget cannot be sensibly diagnosed based on output from current NWP models. Despite this shortcoming, numerical models are in general the most appropriate tool for examining the atmospheric water balance over the Murray–Darling Basin, as the atmospheric sounding network in Australia has extremely low coverage.
8
Pigram, John J. "Towards Upstream-Downstream HydrosolidarityAustralia's Murray-Darling River Basin". Water International 25, n. 2 (giugno 2000): 222–26. http://dx.doi.org/10.1080/02508060008686822.
Testo completo
9
Quiggin, John. "Environmental economics and the Murray–Darling river system". Australian Journal of Agricultural and Resource Economics 45, n. 1 (marzo 2001): 67–94. http://dx.doi.org/10.1111/1467-8489.00134.
Testo completo
10
Gehrke, Peter C., e John H. Harris. "Large-scale patterns in species richness and composition of temperate riverine fish communities, south-eastern Australia". Marine and Freshwater Research 51, n. 2 (2000): 165. http://dx.doi.org/10.1071/mf99061.
Testo completoAbstract (sommario):
Riverine fish in New South Wales were studied to examine longitudinal trends in species richness and to identify fish communities on a large spatial scale. Five replicate rivers of four types (montane, slopes, regulated lowland and unregulated lowland) were selected from North Coast, South Coast, Murray and Darling regions. Fishwere sampled during summer and winter in two consecutive years with standardized gear that maximized the range of species caught. The composition of fish communities varied among regions and river types, with little temporal variation. Distinct regional communities converged in montane reaches and diverged downstream. The fish fauna can be classified into North Coast, South Coast, Murray and Darling communities, with a distinct montane community at high elevations irrespective of the drainage division. Species richness increased downstream in both North Coast and South Coast regions by both replacement and the addition of new species. In contrast, species richness in the Darling and Murray regions reached a maximum in the slopes reaches and then declined, reflecting a loss of species in lowland reaches. The small number of species is typical of the freshwater fish faunas of similar climatic regions world-wide. Fish communities identified in this study form logical entities for fisheries management consistent with the ecosystem-focused, catchment-based approach to river management and water reform being adopted in Australia.
11
Gippel, C., T. Jacobs e T. McLeod. "Environmental flows and water quality objectives for the River Murray". Water Science and Technology 45, n. 11 (1 giugno 2002): 251–60. http://dx.doi.org/10.2166/wst.2002.0402.
Testo completoAbstract (sommario):
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.
12
Whiterod, Nick R., e Keith F. Walker. "Will rising salinity in the Murray - Darling Basin affect common carp (Cyprinus carpio L.)?" Marine and Freshwater Research 57, n. 8 (2006): 817. http://dx.doi.org/10.1071/mf06021.
Testo completoAbstract (sommario):
Salinisation in the Murray–Darling Basin, Australia, may affect aquatic flora and fauna, including the common carp, an alien species that has become the most common fish in the river system. This study describes the responses of juvenile carp (31–108 mm total length) to salinity levels that prevail in some wetlands of the lower reaches of the River Murray. Carp are moderately tolerant of salinity (direct transfer LC50: 11 715 mg L–1), particularly after slow acclimation (LC50: 13 070 mg L–1), but sub-lethal effects are evident at lower salinities. These include effects on osmoregulation (>7500 mg L–1), behaviour (7500–12 500 mg L–1) and sperm motility in mature fish (150–300 mm) (8330 mg L–1). Salinities in some Murray–Darling Basin wetlands already approach half seawater (17 500 mg L–1) and carp populations in these important nursery areas could be impacted through sub-lethal effects on adults and lethal effects on juveniles, eggs and sperm.
13
Crook, David A., Damien J. O'Mahony, Bronwyn M. Gillanders, Andrew R. Munro, Andrew C. Sanger, Stephen Thurstan e Lee J. Baumgartner. "Contribution of stocked fish to riverine populations of golden perch (Macquaria ambigua) in the Murray–Darling Basin, Australia". Marine and Freshwater Research 67, n. 10 (2016): 1401. http://dx.doi.org/10.1071/mf15037.
Testo completoAbstract (sommario):
Stocking of native fishes is conducted to augment riverine fisheries in many parts of the world, yet most stocking activities are conducted without empirical information on their effectiveness or impacts. In the Murray–Darling Basin (MDB), Australia, stocking has been underway for several decades to maintain recreational fisheries. We stocked chemically tagged golden perch (Macquaria ambigua) fingerlings in three rivers to determine the proportions of stocked fish within populations of the species. Stocked sites were monitored for up to 5 years in the Murrumbidgee River, Edward River and Billabong Creek and non-stocked sites were monitored in the Murray River. Catch per unit effort of stocked year classes increased substantially in Billabong Creek, with stocked fish contributing 100 (2005), 79 (2006) and 92% (2007). Chemically tagged fish comprised 18–38% of the respective age classes in the Murrumbidgee and Edward rivers and there was little evidence of natural recruitment in the non-stocked Murray River. Tagged fish generally attained the legal minimum size within 4 years and had dispersed up to 60km from the original release location. Our results demonstrate that artificial stocking has the potential to strongly influence the abundance and population structure of golden perch in rivers of the MDB.
14
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. 3 (2005): 137. http://dx.doi.org/10.1071/zo04086.
Testo completoAbstract (sommario):
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.
15
Yang, Ang, Geoff Podger, Shane Seaton e Robert Power. "A river system modelling platform for Murray-Darling Basin, Australia". Journal of Hydroinformatics 15, n. 4 (29 marzo 2012): 1109–20. http://dx.doi.org/10.2166/hydro.2012.153.
Testo completoAbstract (sommario):
Global climate change and local development make water supply one of the most vulnerable sectors in Australia. The Australian government has therefore commissioned a series of projects to evaluate water availability and the sustainable use of water resources in Australia. This paper discusses a river system modelling platform that has been used in some of these nationally significant projects. The platform consists of three components: provenance, modelling engine and reporting database. The core component is the modelling engine, an agent-based hydrological simulation system called the Integrated River System Modelling Framework (IRSMF). All configuration information and inputs to IRSMF are recorded in the provenance component so that modelling processes can be reproduced and results audited. The reporting database is used to store key statistics and raw output time series data for selected key parameters. This river system modelling platform has for the first time modelled a river system at the basin level in Australia. It provides practitioners with a unique understanding of the characteristics and emergent behaviours of river systems at the basin level. Although the platform is purpose-built for the Murray-Darling Basin, it would be easy to apply it to other basins by using different river models to model agent behaviours.
16
Hamilton, Serena H., Carmel A. Pollino e Keith F. Walker. "Regionalisation of freshwater fish assemblages in the Murray–Darling Basin, Australia". Marine and Freshwater Research 68, n. 4 (2017): 629. http://dx.doi.org/10.1071/mf15359.
Testo completoAbstract (sommario):
Regionalisations based on species assemblages are a useful framework for characterising ecological communities and revealing patterns in the environment. In the present study, multivariate analyses are used to discern large-scale patterns in fish assemblages in the Murray–Darling Basin, based on information from the Murray–Darling Basin Authority’s first Sustainable Rivers Audit (SRA), conducted in 2004–2007. The Basin is classified into nine regions with similar historical fish assemblages (i.e. without major human intervention), using data that combine expert opinion, museum collections and historical records. These regions are (1) Darling Basin Plains, (2) Northern Uplands, (3) Murray Basin Plains, (4) Northern Alps, (5) Central East, (6) Avoca Lowland, (7) Southern Slopes, (8) Southern Alps and (9) South-Western Slopes. Associations between assemblages and physical variables (catchment area, elevation, hydrology, precipitation, temperature) are identified and used to reinforce the definitions of regions. Sustainable Rivers Audit data are compared with the historical assemblages, highlighting species whose range and abundance have changed since the early 19th century. Notable changes include declines in native species such as silver perch, river blackfish, mountain galaxias, Macquarie perch, trout cod and freshwater catfish, and the advent of alien species including common carp, eastern gambusia, goldfish, redfin perch, brown trout and rainbow trout. Less significant declines are evident for native carp gudgeons, golden perch, two-spined blackfish, bony herring and flathead gudgeon. Changes are evident even in regions where habitats have been little disturbed in the past 200 years.
17
Davies, P. E., J. H. Harris, T. J. Hillman e K. F. Walker. "The Sustainable Rivers Audit: assessing river ecosystem health in the Murray - Darling Basin, Australia". Marine and Freshwater Research 61, n. 7 (2010): 764. http://dx.doi.org/10.1071/mf09043.
Testo completoAbstract (sommario):
The Sustainable Rivers Audit (SRA) is a systematic assessment of the health of river ecosystems in the Murray–Darling Basin (MDB), Australia. It has similarities to the United States’ Environmental Monitoring and Assessment Program, the European Water Framework Directive and the South African River Health Program, but is designed expressly to represent functional and structural links between ecosystem components, biophysical condition and human interventions in the MDB. Environmental metrics derived from field samples and/or modelling are combined as indicators of condition in five themes (Hydrology, Fish, Macroinvertebrates, Vegetation and Physical Form). Condition indicator ratings are combined using expert-system rules to indicate ecosystem health, underpinned by conceptual models. Reference condition, an estimate of condition had there been no significant human intervention in the landscape, provides a benchmark for comparisons. To illustrate, a synopsis is included of health assessments in 2004–2007. This first audit completed assessments of condition and ecosystem health at the valley scale and in altitudinal zones, and future reports will include trend assessments. SRA river-health assessments are expected to play a key role in future water and catchment management through integration in a Basin Plan being developed by the Murray–Darling Basin Authority for implementation after 2011. For example, there could be links to facilitate monitoring against environmental targets.
18
Goss, Kevin F. "Environmental flows, river salinity and biodiversity conservation: managing trade-offs in the Murray - Darling basin". Australian Journal of Botany 51, n. 6 (2003): 619. http://dx.doi.org/10.1071/bt03003.
Testo completoAbstract (sommario):
The Murray–Darling basin's river system suffers from over-allocation of water resources to consumptive use and salinity threats to water quality. This paper draws attention to the current state of knowledge and the need for further investigations into the biological effect of river salinity on aquatic biota and ecosystems, the threats of dryland salinity to terrestrial biodiversity, and managing environmental flows and salinity control to limit the trade-offs in water-resource security and river salinity.There is growing evidence that river salt concentrations lower than the normally adopted threshold have sublethal effects on species and ecosystems, over a longer time period. Further knowledge is required.There is no agreed process for incorporating terrestrial biodiversity values at risk into a strategic response for dryland-salinity management. This is a public policy issue to be addressed.Recent studies have quantified the trade-off in surface water flow and river salinity from refforestation and revegetation of upland catchments to control salinity. The potential losses or benefits to environmental values have not been quantified.Such improved knowledge is important to the Murray–Darling basin and relevant to other river basins and catchments in Australia.
19
Tibby, John, e Michael A. Reid. "A model for inferring past conductivity in low salinity waters derived from Murray River (Australia) diatom plankton". Marine and Freshwater Research 55, n. 6 (2004): 597. http://dx.doi.org/10.1071/mf04032.
Testo completoAbstract (sommario):
Detecting human-induced salinisation in rivers and wetlands of the Murray-Darling Basin has proved problematic. A diatom-based model that permits the estimation of past electrical conductivity (EC) from sedimentary diatom sequences has been developed from Murray River planktonic diatoms. Canonical Correspondence Analysis indicates that EC explains the greatest amount of variance in Murray River planktonic diatoms and that its influence is partially independent of that associated with velocity, turbidity, pH and nutrients. A weighted-averaging based model for inferring past EC was therefore derived from the relationship between diatom composition and EC in Murray River plankton samples. The model works well when comparisons are made between measured and diatom-inferred EC determined by jackknifing based leave-one-out computer resampling (r2jack = 0.71, root-mean-square-error of prediction = 115 μS cm−1). Application of the model will enhance understanding of the nature of pre-European variability in electrical conductivity and permit detection of changes in conductivity through the period of European occupation at key sites. Such reconstructions will provide a firm empirical basis for assessing European impact on aquatic ecosystems and a means by which to assess restoration efforts.
20
Gehrke, P. C., P. Brown, C. B. Schiller, D. B. Moffatt e A. M. Bruce. "River regulation and fish communities in the Murray-Darling river system, Australia". Regulated Rivers: Research & Management 11, n. 3-4 (novembre 1995): 363–75. http://dx.doi.org/10.1002/rrr.3450110310.
Testo completo
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Hart, Barry, Glen Walker, Asitha Katupitiya e Jane Doolan. "Salinity Management in the Murray–Darling Basin, Australia". Water 12, n. 6 (26 giugno 2020): 1829. http://dx.doi.org/10.3390/w12061829.
Testo completoAbstract (sommario):
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.
22
Stewart, G., e B. Harper. "Barmah-Millewa forest environmental water allocation". Water Science and Technology 45, n. 11 (1 giugno 2002): 217–23. http://dx.doi.org/10.2166/wst.2002.0398.
Testo completoAbstract (sommario):
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.
23
Garrick, Dustin, Rosalind Bark, Jeff Connor e Onil Banerjee. "Environmental water governance in federal rivers: opportunities and limits for subsidiarity in Australia's Murray–Darling River". Water Policy 14, n. 6 (14 agosto 2012): 915–36. http://dx.doi.org/10.2166/wp.2012.120.
Testo completoAbstract (sommario):
A reform process is underway in the Murray–Darling Basin (Australia) to reallocate water from irrigated agriculture to the environment. The scale, complexity and politics of the recovery process have prompted interest in the role of local environmental water managers within state and federal governance arrangements. This paper examines prospects for a local role in environmental water management through the lens of the subsidiarity principle: the notion that effective governance devolves tasks to the lowest level with the political authority and capacity to perform them. The article defines and applies the subsidiarity principle to assess evolving federal–state–local interactions in environmental water policy, planning and practice in Australia's Murray–Darling River. In this context, subsidiarity is useful to clarify institutional roles and their coordination at a whole-of-river level. This analysis demonstrates opportunities for a local role in information gathering, innovation and operational flexibility to respond to opportunities in real time. It identifies significant limits to local action in upstream–downstream tradeoffs, economies of scale, capacity building and cost sharing for basin-wide or national interests, and accountability mechanisms to balance local, state and national rights and responsibilities. Lessons are relevant internationally for regions confronting complex allocation tradeoffs between human and environmental needs within multi-jurisdictional federal systems.
24
T. Kingsford, Richard. "Managing Australia's Scarce Water Resources for the Environment". Pacific Conservation Biology 15, n. 1 (2009): 4. http://dx.doi.org/10.1071/pc090004.
Testo completoAbstract (sommario):
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.
25
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. 2002 (13 novembre 2013): 20120415. http://dx.doi.org/10.1098/rsta.2012.0415.
Testo completoAbstract (sommario):
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.
26
Tibby, John, Deborah Haynes e Kerri Muller. "The predominantly fresh history of Lake Alexandrina, South Australia, and its implications for the Murray–Darling Basin Plan: a comment on Gell (2020)". Pacific Conservation Biology 26, n. 2 (2020): 142. http://dx.doi.org/10.1071/pc19039.
Testo completoAbstract (sommario):
The pre-European settlement state of Lake Alexandrina, a lake system at the mouth of the River Murray has been the subject of some debate. Fluin et al. (2007) concluded on the basis of diatom evidence from sediment cores that ‘Marine water indicators were never dominant in Lake Alexandrina’. In a report to the South Australian Government, Fluin et al. (2009) stated, consistent with the earlier research, that ‘There is no evidence in the 7000 year record of substantial marine incursions into Lake Alexandrina’. Gell (2020) has argued both that Fluin et al. (2009) is in error and claims that it, and Sim and Muller’s (2004) book that describes early European settler accounts of the lake being fresh, underpin water provisions for Lake Alexandrina under the Murray–Darling Basin Plan. This response demonstrates that all these claims are untrue. Of the three diatom species suggested by Gell (2020) to be indicators of marine waters, Thalassiosira lacustris grows in the freshwater River Murray today, Cyclotella striata was never more than a minor component of the diatom flora and Paralia sulcata has not been detected in the lake in over 3000 years. Water provisions for Lake Alexandrina under The Basin Plan are founded on contemporary environmental water requirements and achievement of agreed socio-ecological-economic objectives, rather than the history of the lake. Nevertheless, the aim to maintain the lake as a freshwater ecosystem under The Murray–Darling Basin Plan is consistent with its history.
27
Stuart, Ivor G., e Matthew Jones. "Large, regulated forest floodplain is an ideal recruitment zone for non-native common carp (Cyprinus carpio L.)". Marine and Freshwater Research 57, n. 3 (2006): 333. http://dx.doi.org/10.1071/mf05035.
Testo completoAbstract (sommario):
Non-native common carp (Cyprinus carpio L.) are the most abundant large-bodied fish in the Murray–Darling Basin. The abundance of common carp larvae and young-of-the-year appears to increase after flooding, although the relative contribution of floodplain habitats compared to riverine areas remains unresolved. Larval nets were used monthly from September 2000 to January 2001 to identify common carp spawning and recruitment areas in the regulated Murray River and floodplain around the Barmah–Millewa forest. Five non-native and five native fish species comprising 136 111 individuals were collected, with common carp constituting 88% of the overall catch. Less than 1% of common carp, however, originated from the Murray River upstream of the Barmah–Millewa floodplain. Consequently, this floodplain appears to be a major source of common carp recruitment in the mid-Murray area. Conversely, eggs from large-bodied native fish were only present in the Murray River and not the Barmah floodplain. There are opportunities for common carp control in this area, to potentially reduce populations in a wider river reach. Implementation of common carp control measures in the Barmah–Millewa floodplain should be further investigated, particularly with regard to seasonal irrigation flows, obligatory migration routes and in the timing of future large-scale environmental water allocations.
28
Leigh, Sandra J., e Brenton P. Zampatti. "Movement and mortality of Murray cod, Maccullochella peelii, during overbank flows in the lower River Murray, Australia". Australian Journal of Zoology 61, n. 2 (2013): 160. http://dx.doi.org/10.1071/zo12124.
Testo completoAbstract (sommario):
Conservation of Murray cod (Maccullochella peelii), a large endangered fish species of Australia’s Murray–Darling Basin, relies on a detailed understanding of life history, including movement patterns and habitat use. We used radio-tracking to investigate the movement of 36 Murray cod in main channel and anabranch habitats of the lower River Murray during a flood and associated hypoxic blackwater event. During a flood peak of ~93 000 ML day–1, dissolved oxygen decreased to 1.2 mg L–1. Four movement types were observed: (1) localised small-scale movement, (2) broad-scale movement within anabranch habitats, (3) movement between anabranch and main channel habitats, and (4) large-scale riverine movement. Murray cod exhibited high fidelity to anabranch habitats but also moved extensively between anabranches and the main channel. Fish were consistently located in the main channel or permanent anabranches, suggesting that use of ephemeral floodplain habitats is limited, and highlighting the importance of connectivity between off-channel and main channel habitats. Mortality of radio-tagged fish was considerable (25%) in association with low dissolved oxygen concentrations, indicating that hypoxic blackwater may have had a substantial impact on Murray cod populations in the lower River Murray.
29
Cunningham, Shaun C., Jennifer Read, Patrick J. Baker e Ralph Mac Nally. "Quantitative assessment of stand condition and its relationship to physiological stress in stands of Eucalyptus camaldulensis (Myrtaceae)". Australian Journal of Botany 55, n. 7 (2007): 692. http://dx.doi.org/10.1071/bt07031.
Testo completoAbstract (sommario):
River regulation has led to a decline in the condition of Australia’s dominant riverine tree species, Eucalyptus camaldulensis Dehnh., in the Murray–Darling Basin. A quantitative method of assessing the condition of these important riparian forests is required for effective monitoring and management. A range of stand structural, morphological and physiological variables was measured in stands of contrasting condition along the Murray River in south-eastern Australia. Percentage live basal area, plant area index and crown vigour were found to be reliable, objective indicators of stand condition. Little difference was detected in the physiological performance of trees in terms of water potential and chlorophyll fluorescence among stands of good and poor condition.
30
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. 1 (2001): 7. http://dx.doi.org/10.1071/sr99078.
Testo completoAbstract (sommario):
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.
31
Kneebone, Jo, e Belinda Wilson. "Design and Early Implementation of the Murray–Darling Basin Plan". Water Economics and Policy 03, n. 03 (9 gennaio 2017): 1650041. http://dx.doi.org/10.1142/s2382624x16500417.
Testo completoAbstract (sommario):
Australia’s Murray–Darling Basin extends over one million square kilometers and supports almost three-quarters of the country’s irrigated agricultural land. Like the Colorado River in America and the Yellow River in China, the Murray–Darling Basin runs across a number of jurisdictional boundaries, and has been a focus for national water reforms for many years. The Murray–Darling Basin Plan is the culmination of more than two decades of water reform experience in Australia. It was adopted by the Commonwealth Water Minister in 2012 to rebalance use of water resources and create a more sustainable footing for a healthy working Basin. The Basin Plan was based on the best science at the time, which was endorsed by peer review. The key features of the Basin Plan that are integrated into its design are optimizing social, economic and environmental (triple bottom line) outcomes; improving transparency of decision-making and flexible and adaptive management. As a result of widespread consultation, the Basin Plan also included suggestions from jurisdictions and communities that served to better balance the competing interests for water resources, and provided a clearly defined timetable for implementation to create certainty for communities and investment. The Basin Plan commenced on 29 November 2012, and early implementation activities are well progressed, meaning that water resources are already better positioned to cope with major drought. Looking forward, continued support for Basin Plan reforms from governments and communities will be an ongoing challenge for implementation. Similarly, separating out the effects of the Basin Plan from other external effects on the social and economic well-being of Basin communities will be a challenge when evaluating whether the Basin Plan has achieved its triple bottom line outcomes and objectives.
32
Couch, Alan J., Peter J. Unmack, Fiona J. Dyer e Mark Lintermans. "Who’s your mama? Riverine hybridisation of threatened freshwater Trout Cod and Murray Cod". PeerJ 4 (27 ottobre 2016): e2593. http://dx.doi.org/10.7717/peerj.2593.
Testo completoAbstract (sommario):
Rates of hybridization and introgression are increasing dramatically worldwide because of translocations, restocking of organisms and habitat modifications; thus, determining whether hybridization is occuring after reintroducing extirpated congeneric species is commensurately important for conservation. Restocking programs are sometimes criticized because of the genetic consequences of hatchery-bred fish breeding with wild populations. These concerns are important to conservation restocking programs, including those from the Australian freshwater fish family, Percichthyidae. Two of the better known Australian Percichthyidae are the Murray Cod,Maccullochella peeliiand Trout Cod,Maccullochella macquariensiswhich were formerly widespread over the Murray Darling Basin. In much of the Murrumbidgee River, Trout Cod and Murray Cod were sympatric until the late 1970s when Trout Cod were extirpated. Here we use genetic single nucleotide polymorphism (SNP) data together with mitochondrial sequences to examine hybridization and introgression between Murray Cod and Trout Cod in the upper Murrumbidgee River and consider implications for restocking programs. We have confirmed restocked riverine Trout Cod reproducing, but only as inter-specific matings, in the wild. We detected hybrid Trout Cod–Murray Cod in the Upper Murrumbidgee, recording the first hybrid larvae in the wild. Although hybrid larvae, juveniles and adults have been recorded in hatcheries and impoundments, and hybrid adults have been recorded in rivers previously, this is the first time fertile F1 have been recorded in a wild riverine population. The F1 backcrosses with Murray cod have also been found to be fertile. All backcrosses noted were with pure Murray Cod. Such introgression has not been recorded previously in these two species, and the imbalance in hybridization direction may have important implications for restocking programs.
33
Parsons, Melissa, Martin C. Thoms e Joseph E. Flotemersch. "Eight river principles for navigating the science–policy interface". Marine and Freshwater Research 68, n. 3 (2017): 401. http://dx.doi.org/10.1071/mf15336.
Testo completoAbstract (sommario):
Scientists and policymakers often work together to develop policy about the sustainable use of river ecosystems. River science plays an important role in developing river policy but how can key aspects of river science be conveyed as a heuristic to navigate the interface between river science and river policy? This paper introduces eight principles that encapsulate the key properties of rivers to consider during the development of river policy: (1) rivers are social–ecological systems; (2) river ecosystems provide valuable ecosystem services; (3) tools should support policy development; (4) knowledge of river ecosystems will always be incomplete; (5) social–ecological systems require interdisciplinary perspectives; (6) science is one of many inputs to be considered; (7) heterogeneity and variability are characteristic of river ecosystems; and (8) scale awareness is essential in river ecosystems. Whereas policy challenges are associated with each principle, consideration of principles in the context of the issue at hand may increase the robustness of river policy and enhance the sustainability of river ecosystems. The eight principles are evaluated in relation to the Water Act 2007 and the draft Murray–Darling Basin Plan to demonstrate how the principles can enhance policy development in the area of water allocation.
34
Allan, Catherine, e Robyn J. Watts. "Framing Two Environmental Flow Trials in the Murray-Darling Basin, South-Eastern Australia". Water 14, n. 3 (29 gennaio 2022): 411. http://dx.doi.org/10.3390/w14030411.
Testo completoAbstract (sommario):
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.
35
Papas, Maureen. "Supporting Sustainable Water Management: Insights from Australia’s Reform Journey and Future Directions for the Murray–Darling Basin". Water 10, n. 11 (14 novembre 2018): 1649. http://dx.doi.org/10.3390/w10111649.
Testo completoAbstract (sommario):
Effective regulation of freshwater remains one of the biggest challenges facing our societies. In times of record-breaking weather extremes spurred by a changing climate, decision makers are increasingly aware of the need to formulate more effective governance to ensure the reliability, accessibility, and quality of this life-giving resource. In recent years, the Australian government has played a key role in water management. The government has managed a significant amount of water entitlements in the Murray–Darling Basin (MDB), through its Commonwealth Environmental Water Holder (CEWH) agency, in a bid to increase river flows and thus improve the river system’s environmental and ecological conditions. The CEWH is unique in many respects, and the Australian government’s control of its budget and actions is a critical aspect of the Basin’s sustainable long-term management. Despite the importance of this instrument, this article points out that there are serious issues with the current governance arrangements, such as inherent conflicts in the Murray–Darling Basin Authority’s (MDBA) role, which is a concern raised by the Productivity Commission. This article goes on to recommend the policy changes required to address Basin-wide issues and promote sustainable practices to ensure the MDB’s long-term resilience.
36
Wheeler, Kevin G., Catherine J. Robinson e Rosalind H. Bark. "Modelling to bridge many boundaries: the Colorado and Murray-Darling River basins". Regional Environmental Change 18, n. 6 (5 marzo 2018): 1607–19. http://dx.doi.org/10.1007/s10113-018-1304-z.
Testo completo
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. 10 (2010): 1207. http://dx.doi.org/10.1071/mf09312.
Testo completoAbstract (sommario):
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
Shi, Zhuolin, Yun Chen, Qihang Liu e Chang Huang. "Discharge Estimation Using Harmonized Landsat and Sentinel-2 Product: Case Studies in the Murray Darling Basin". Remote Sensing 12, n. 17 (30 agosto 2020): 2810. http://dx.doi.org/10.3390/rs12172810.
Testo completoAbstract (sommario):
Quantifying river discharge is a critical component for hydrological studies, floodplain ecological conservation research, and water resources management. In recent years, a series of remote sensing-based discharge estimation methods have been developed. An example is the use of the near infrared (NIR) band of optical satellite images, with the principle of calculating the ratio between a stable land pixel for calibration (C) and a pixel within the river for measurement (M), applying a linear regression between C/M series and observed discharge series. This study trialed the C/M method, utilizing the Harmonized Landsat and Sentinel-2 (HLS) surface reflectance product on relatively small rivers with 30~100 m widths. Two study sites with different river characteristics and geographic settings in the Murray-Darling Basin (MDB) of Australia were selected as case studies. Two independent sets of HLS data and gauged discharge data for the 2017 and 2018 water years were acquired for modeling and validation, respectively. Results reveal high consistency between the HLS-derived discharge and gauged discharge at both sites. The Relative Root Mean Square Errors are 53% and 19%, and the Nash-Sutcliffe Efficiency coefficients are 0.24 and 0.69 for the two sites. This study supports the effectiveness of applying the fine-resolution HLS for modeling discharge on small rivers based on the C/M methodology, which also provides evidence of using multisource synthesized datasets as the input for discharge estimation.
39
Grafton, R. Quentin, e Sarah Ann Wheeler. "Economics of Water Recovery in the Murray-Darling Basin, Australia". Annual Review of Resource Economics 10, n. 1 (5 ottobre 2018): 487–510. http://dx.doi.org/10.1146/annurev-resource-100517-023039.
Testo completoAbstract (sommario):
We review recent water reforms and the consequences of water recovery intended to increase stream flows in the Murray-Darling Basin (MDB), Australia. The MDB provides a natural experiment of water recovery for the environment that includes ( a) the voluntary buy-back of water rights from willing sellers and ( b) the subsidization of irrigation infrastructure. We find that ( a) the actual increase in the volumes of water in terms of stream flows is much less than claimed by the Australian government; ( b) subsidies to increase irrigation efficiency have reduced stream and groundwater return flows; ( c) buy-backs are much more cost effective than subsidies; ( d) many of the gains from water recovery have accrued as private benefits to irrigators; and ( e) more than a decade after water recovery began, there is no observable basin-wide relationship between volumes of water recovered and flows at the mouth of the River Murray.
40
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. 2 (2020): 130. http://dx.doi.org/10.1071/pc18085.
Testo completoAbstract (sommario):
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.
41
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. 2 (2020): 211. http://dx.doi.org/10.1071/pc18085_co.
Testo completoAbstract (sommario):
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.
42
Clifford, Katrina, e Rob White. "News media framing of the Murray–Darling Basin ‘water theft’ controversy". Journal of Criminology 54, n. 3 (22 marzo 2021): 365–82. http://dx.doi.org/10.1177/00048658211000094.
Testo completoAbstract (sommario):
An Australian Broadcasting Corporation (ABC) Four Corners investigation, screened on free-to-air television on 24 July 2017, revealed a series of improper conducts pertaining to the Murray–Darling Basin river system. The journalistic exposé included allegations of water theft, questionable compliance decisions and collusion between water regulators and irrigation lobbyists. This interdisciplinary study explores the revelations and their framing in a sample of state and national media reports about the ‘water theft’ controversy and its fallout. It compares these with the normative frames adopted by critical green criminology, which views the allegations at the heart of the Murray–Darling Basin controversy in terms of state-corporate interests, industry capture of regulators and the notion that water ‘theft’ constitutes a ‘crime’ because of the environmental harm that results from excessive water extraction. This article presents the findings of the study, which elaborate on the impacts of media framing of crimes of the powerful (such as large agricultural companies and state government agencies), including the shaping of public understandings of environmental matters.
43
Campbell, Ian, Barry Hart e Chris Barlow. "Integrated Management in Large River Basins: 12 Lessons from the Mekong and Murray-Darling Rivers". River Systems 20, n. 3 (1 aprile 2013): 231–47. http://dx.doi.org/10.1127/1868-5749/2013/0067.
Testo completo
44
Hughes, Jane M., e Mia J. Hillyer. "Patterns of connectivity among populations of Cherax destructor (Decapoda : Parastacidae) in western Queensland, Australia". Marine and Freshwater Research 54, n. 5 (2003): 587. http://dx.doi.org/10.1071/mf03066.
Testo completoAbstract (sommario):
Freshwater organisms are often hypothesized to reflect the hierarchical nature of stream channels in the genetic structure of their populations. However, patterns of genetic structure are also affected by the dispersal mechanism of the particular species and the nature of the river channels. In this study, the genetic structure of a freshwater crayfish, known to have the ability for terrestrial dispersal, was examined in a habitat where stream structure and elevational differences across catchment boundaries are minimal. It was found that levels of connectivity among populations in the same catchment are high, suggesting either recent or contemporary dispersal among them. In contrast, almost no sharing of haplotypes across drainage boundaries indicates limited terrestrial dispersal across them. However, nested clade analysis indicated that, historically, there has been movement between drainages. It is suggested that populations in the Cooper and Murray–Darling were isolated in the past and that, more recently, recolonization has occurred in an east–west direction from the Murray–Darling to the Bulloo and from the Bulloo to the Cooper. These movements probably occurred in wetter times when whole catchments were flooded.
45
Alaghmand, S., S. Beecham e A. Hassanli. "Fully integrated physically-based numerical modelling of impacts of groundwater extraction on surface and irrigation-induced groundwater interactions: case study Lower River Murray, Australia". Natural Hazards and Earth System Sciences Discussions 1, n. 4 (26 luglio 2013): 3577–624. http://dx.doi.org/10.5194/nhessd-1-3577-2013.
Testo completoAbstract (sommario):
Abstract. Combination of reduction in the frequency, duration and magnitude of natural floods, rising saline water-table in floodplains and excessive evapotranspiration have led to an irrigation-induced groundwater mound forced the naturally saline groundwater onto the floodplain in the Lower River Murray. It is during the attenuation phase of floods that these large salt accumulations are likely to be mobilised and will discharge into the river. The Independent Audit Group for Salinity highlighted this as the most significant risk in the Murray–Darling Basin. South Australian government and catchment management authorities have developed salt interception schemes (SIS). This is to pump the highly saline groundwater from the floodplain aquifer to evaporation basins in order to reduce the hydraulic gradient that drives the regional saline groundwater towards the River Murray. This paper investigates the interactions between a river (River Murray in South Australia) and a saline semi-arid floodplain (Clarks Floodplain) significantly influenced by groundwater lowering (Bookpurnong SIS). Results confirm that groundwater extraction maintain a lower water-table and more fresh river water flux to the saline floodplain aquifer. In term of salinity, this may lead to less amount of solute stored in the floodplain aquifer. This occurs through two mechanisms; extracting some of the solute mass from the system and changing the floodplain groundwater regime from a losing to gaining one. Finally, it is shown that groundwater extraction is able to remove some amount of solute stored in the unsaturated zone and mitigate the floodplain salinity risk.
46
Colloff, Matthew J., Peter Caley, Neil Saintilan, Carmel A. Pollino e Neville D. Crossman. "Long-term ecological trends of flow-dependent ecosystems in a major regulated river basin". Marine and Freshwater Research 66, n. 11 (2015): 957. http://dx.doi.org/10.1071/mf14067.
Testo completoAbstract (sommario):
The case for restoring water to the environment in the Murray–Darling Basin, Australia, is based mainly on condition assessments, although time series provide valuable information on trends. We assessed trends of 301 ecological time series (mean 23 years, range 1905–2013) in two categories: (1) ‘population’ (abundance, biomass, extent) and (2) ‘non-population’ (condition, occurrence, composition). We analysed trends using log-linear regression, accounting for observation error only, and a state–space model that accounts for observation error and environmental ‘noise’. Of the log-linear series (n=239), 50 (22%) showed statistically significant decline, but 180 (78%) showed no trend. For state–space series (n=197) one increased, but others were stable. Distribution of median exponential rates of increase (r) indicated a small but statistically significant declining trend, though 35–39% of the series were positive. Our analysis only partly supports, though does not refute, prevailing assumptions of recent ecological decline in the Murray–Darling Basin. The pattern is of fluctuating stability, with declines during droughts and recovery after flood. The overall trend from our meta-analysis is consistent with a pattern of historical decline to a hybrid ecosystem followed by slow, recent decline for some components and stability for others, with considerable variation in trends of specific ecological components: in short, there are ecological ‘winners’ and ‘losers’.
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Gough-Brady, Catherine. "“A River as a Character” (2019)". Video Journal of Education and Pedagogy 4, n. 2 (26 dicembre 2019): 140–46. http://dx.doi.org/10.1163/23644583-00401016.
Testo completoAbstract (sommario):
As a filmmaker, the author felt the need to develop a deep connection with her subject, but was unsure how to do so with the Murray-Darling River. Initially, she saw the river as a system akin to what Pierre Bourdieu calls a field: forces external to the author acting upon each other. She felt that to connect with the river she needed to adjust her habitus (personal dispositions; way of being) to its field. This continued once the author returned to Melbourne, but through the medium of the images of the river. During the edit, she shifted from seeing the river as a field of external forces to seeing it as a habitus, a way of being. This was necessary for the river to become a character, rather than just a location.
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Alaghmand, S., S. Beecham e A. Hassanli. "Impacts of groundwater extraction on salinization risk in a semi-arid floodplain". Natural Hazards and Earth System Sciences 13, n. 12 (23 dicembre 2013): 3405–18. http://dx.doi.org/10.5194/nhess-13-3405-2013.
Testo completoAbstract (sommario):
Abstract. In the lower River Murray in Australia, a combination of a reduction in the frequency, duration and magnitude of natural floods, rising saline water tables in floodplains, and excessive evapotranspiration have led to an irrigation-induced groundwater mound forcing the naturally saline groundwater onto the floodplain. It is during the attenuation phase of floods that these large salt accumulations are likely to be mobilised and discharged into the river. This has been highlighted as the most significant risk in the Murray–Darling Basin and the South Australian Government and catchment management authorities have subsequently developed salt interception schemes (SIS). The aim of these schemes is to reduce the hydraulic gradient that drives the regional saline groundwater towards the River Murray. This paper investigates the interactions between a river (River Murray in South Australia) and a saline semi-arid floodplain (Clark's floodplain) that is significantly influenced by groundwater lowering due to a particular SIS. The results confirm that groundwater extraction maintains a lower water table and a higher amount of fresh river water flux to the saline floodplain aquifer. In terms of salinity, this may lead to less solute stored in the floodplain aquifer. This occurs through three mechanisms, namely extraction of the solute mass from the system, reducing the saline groundwater flux from the highland to the floodplain and changing the floodplain groundwater regime from a losing to a gaining one. It is shown that groundwater extraction is able to remove some of the solute stored in the unsaturated zone and this can mitigate the floodplain salinity risk. A conceptual model of the impact of groundwater extraction on floodplain salinization has been developed.
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King, A. J., Z. Tonkin e J. Lieshcke. "Short-term effects of a prolonged blackwater event on aquatic fauna in the Murray River, Australia: considerations for future events". Marine and Freshwater Research 63, n. 7 (2012): 576. http://dx.doi.org/10.1071/mf11275.
Testo completoAbstract (sommario):
Blackwater contains high levels of dissolved organic carbon that can be rapidly consumed by microbes, sometimes leading to extremely low levels of dissolved oxygen (hypoxia) and drastic consequences for aquatic life, including fish kills. Drought-breaking rains in late 2010 inundated large areas of the Barmah–Millewa Forest, southern Murray–Darling Basin, Australia, and resulted in a prolonged hypoxic blackwater event within the forest and the Murray River downstream. This study investigated the short-term effects of the blackwater event on fish and crayfish. Compared with non-affected sites, blackwater affected sites had: significantly higher abundances of emerged Murray crayfish (Euastacus armatus) that were vulnerable to desiccation, predation and exploitation; large numbers of dead or dying shrimp and yabbies; significantly reduced abundances of native fish; but contained similar abundances of alien fish species (particularly common carp, Cyprinus carpio). The nature of the mechanisms that caused these changes and the longer term significance of the event on the river system remains an important area for future research. We also propose a range of management considerations for reducing the blackwater impacts, such as the timing of environmental water delivery after prolonged drought and the importance of maintaining river–floodplain connectivity during flood periods.
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Growns, Ivor, Iris Wing Tsoi, Mark Southwell, Sarah Mika, Sam Lewis e Ben Vincent. "The effects of hydrology on macroinvertebrate traits in river channel and wetland habitats". Aquatic Ecosystem Health & Management 24, n. 4 (1 ottobre 2021): 93–102. http://dx.doi.org/10.14321/aehm.024.04.12.
Testo completoAbstract (sommario):
Abstract Increased need for freshwater for human uses from the mid-1900s has severely impacted rivers and floodplain wetlands so that they are some of the most seriously degraded environments in the world. Research and monitoring in this area to date has focused on understanding ‘flow-ecology’ relationships, without investigating the mechanisms underlying them. The use of species traits offers a tool for defining mechanistic connections between biotic responses and environmental conditions. We examined nine macroinvertebrate trait categories in both wetlands and channels to determine whether their profiles responded to hydrology in the Gwydir River system in the northern Murray-Darling Basin, Australia. Trait responses were shown for the wetlands but not the river channels. Twelve traits showed positive relationships with the time the wetlands were connected to their river channels. It is unclear the reason(s) why the river channel invertebrate traits did not respond to hydrology. However, the use of environmental flows in the river systems may be important to other aspects of macroinvertebrate assemblages such as their role in food webs to support higher-order consumers.