Journal articles on the topic 'Catchment salinity'
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1
Lymbery, A. J., R. G. Doupé, and N. E. Pettit. "Effects of salinisation on riparian plant communities in experimental catchments on the Collie River, Western Australia." Australian Journal of Botany 51, no. 6 (2003): 667. http://dx.doi.org/10.1071/bt02119.
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Although the salinisation of streams has long been recognised as one of Western Australia's most serious environmental and resource problems, there is very little published information on the effects of salinisation on riparian flora and fauna. We studied riparian vegetation in three experimental catchments on the Collie River in Western Australia. The catchments are situated within a 5-km area of state forest and are geologically and botanically similar, but differ in the extent of clearing, groundwater levels and stream salinity. In each catchment, transects were taken perpendicular to the direction of streamflow, and 4-m2 quadrats taken along each transect. Within each quadrat, soil salinity was measured, all plants were identified to species level and percentage cover estimated. The catchments differed significantly in soil salinity, with salinity being greatest in the most extensively cleared catchment and increasing towards the floor of the valley. Plant-species richness, species diversity and species composition were significantly related to soil salinity, both among catchments and among quadrats within the most extensively cleared catchment. Plant-species richness and diversity decreased with increasing soil salinity, an effect that may be partly due to a decline in perennial herb and shrub species. This may have an impact on other components of the riparian ecosystem.
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Dawes, W. R., M. Gilfedder, M. Stauffacher, J. Coram, S. Hajkowicz, G. R. Walker, and M. Young. "Assessing the viability of recharge reduction fordryland salinity control: Wanilla, Eyre Peninsula." Soil Research 40, no. 8 (2002): 1407. http://dx.doi.org/10.1071/sr01044.
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The emerging paradigm to manage the spread of dryland salinity is the manipulation of farming practice to provide both a reduction in recharge and a commercial return to farm enterprises. Recent work has attempted to classify the groundwater systems across Australia into distinct provinces, with the implication that the flow processes, and therefore remediation strategies, of catchments within each province are similar. This paper presents a case study of the Wanilla catchment on the Eyre Peninsula in South Australia. This catchment is in the groundwater province that includes 60% of the dryland salinity expression in Australia. The results of conceptual and numerical modelling of the catchment suggest that the land management for reduced recharge paradigm may be less effective in this groundwater province than in others. The scale of expression and salinity history of such catchments provides further impediments to management options aimed at controlling or reversing existing dryland salinity.
3
Clarke, C. J., R. J. George, R. W. Bell, and R. J. Hobbs. "Major faults and the development of dryland salinity in the western wheatbelt of Western Australia." Hydrology and Earth System Sciences 2, no. 1 (March 31, 1998): 77–91. http://dx.doi.org/10.5194/hess-2-77-1998.
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Abstract. Dryland salinity poses a major threat to agricultural production in the wheatbelt of Western Australia and much time and effort is expended on understanding the mechanisms which cause it and on developing techniques to halt or reverse its development. Whilst the location of much dryland salinity can be explained by its topographic position, a significant proportion of it cannot. This study investigated the hypothesis that major faults in the Yilgarn Craton represented in aeromagnetic data by intense curvilinear lows explained the location of areas of dryland salinity not explained by topography. Moreover, the causal mechanisms that might underpin a spatial relationship between major faults and dryland salinity were sought. In one fourth order catchment, nearly 85% of the salinity that was not explained topographically was within 2km of the centre line of a major fault, the remaining 15% being in the other 12km of the catchment. Three groups of similar third order catchments in the western wheatbelt of Western Australia were also investigated; in each case the catchment that was underlain by a major fault had dryland salinity an order of magnitude more than the unfaulted catchment(s). This evidence demonstrates a strong spatial association between major faults and the development of dryland salinity. Other evidence suggests that the underlying mechanism is hydraulic conductivity 5.2 to 2.9 times higher inside the fault zone compared to outside it and shows that geomorphology, salt store, regolith thickness, and degree of clearing are not the underlying mechanisms. In one of the groups of catchments, it has been calculated that an amount of recharge, significant in relation to recharge from rainfall, was entering from an adjacent catchment along a major fault. The paper concludes that geological features such as major faults affect the development of dryland salinity in the wheatbelt of Western Australia because of permeability differences in the regolith and therefore computer models of salinity risk need to take these differences into account. Techniques need to be developed to map, quickly and relatively cheaply, the geology-related permeability differences over wide areas of the landscape.
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Casanova, Michelle T. "Historical water-plant occurrence and environmental change in two contrasting catchments." Marine and Freshwater Research 67, no. 2 (2016): 210. http://dx.doi.org/10.1071/mf14189.
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Historical conditions in riparian systems can be derived from the recorded distribution of water plants and their ecological requirements. Herbarium and literature records were used to assess historical species occurrence, and a field survey and a seed-bank study were used to assess present-day occurrence in two adjacent, southern Australian catchments: the Angas River and the Tookayerta Creek. There was an increase in the proportion of salinity- and drought-tolerant species detected in the Angas River catchment since European settlement. Field-survey data and the seed-bank study data were similar for that catchment, indicating that the submerged flora of the Angas River catchment is resilient to drought. In contrast, the dissimilarity of the seed-bank study data and the survey data from the Tookayerta Creek catchment indicated that the submerged flora in that catchment is not tolerant of drought. Although submerged species in the Tookayerta Creek catchment are dependent on the presence of permanent fresh water, there were more salinity-tolerant species in the lower Tookayerta catchment in the present study than were detected in the past. Comparison of the historical plant distribution and present-day distribution in catchments can provide interpretation of environmental conditions and ecological filters now, and since European settlement.
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Liu, Shuci, Dongryeol Ryu, J. Angus Webb, Anna Lintern, Danlu Guo, David Waters, and Andrew W. Western. "A Bayesian approach to understanding the key factors influencing temporal variability in stream water quality – a case study in the Great Barrier Reef catchments." Hydrology and Earth System Sciences 25, no. 5 (May 20, 2021): 2663–83. http://dx.doi.org/10.5194/hess-25-2663-2021.
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Abstract. Stream water quality is highly variable both across space and time. Water quality monitoring programmes have collected a large amount of data that provide a good basis for investigating the key drivers of spatial and temporal variability. Event-based water quality monitoring data in the Great Barrier Reef catchments in northern Australia provide an opportunity to further our understanding of water quality dynamics in subtropical and tropical regions. This study investigated nine water quality constituents, including sediments, nutrients and salinity, with the aim of (1) identifying the influential environmental drivers of temporal variation in flow event concentrations and (2) developing a modelling framework to predict the temporal variation in water quality at multiple sites simultaneously. This study used a hierarchical Bayesian model averaging framework to explore the relationship between event concentration and catchment-scale environmental variables (e.g. runoff, rainfall and groundcover conditions). Key factors affecting the temporal changes in water quality varied among constituent concentrations and between catchments. Catchment rainfall and runoff affected in-stream particulate constituents, while catchment wetness and vegetation cover had more impact on dissolved nutrient concentration and salinity. In addition, in large dry catchments, antecedent catchment soil moisture and vegetation had a large influence on dissolved nutrients, which highlights the important effect of catchment hydrological connectivity on pollutant mobilisation and delivery.
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Mcfarlane, DJ, and RJ George. "Factors affecting dryland salinity in two wheat belt catchments in Western Australia." Soil Research 30, no. 1 (1992): 85. http://dx.doi.org/10.1071/sr9920085.
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We investigated why the Wallatin Creek Catchment in the Western Australian wheatbelt had an appreciable area of secondary salinity whereas the adjoining North Baandee Catchment had almost none. The Wallatin Creek Catchment, which is long and narrow, had a shallow regolith over granite bedrock. Although this catchment had less salt stored in the regolith than the wider North Baandee Catchment, the groundwaters came close to the ground surface because the regolith was thin and the valley cross-section narrow. Management practices which increase recharge (e.g. using level banks to control runoff), are likely to result in increased salinity in the short term in the Wallatin Creek Catchment. We also investigated whether retaining areas of remnant vegetation had reduced the amount of secondary salinity in a sub-catchment of the Wallatin Creek Catchment. At comparable positions in the landscape, groundwater levels were up to 7 m lower under the remnant vegetation. The vegetation appears to have delayed, if not prevented, the development of salinity in nearby and downslope areas.
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Beverly, C., M. Bari, B. Christy, M. Hocking, and K. Smettem. "Predicted salinity impacts from land use change: comparison between rapid assessment approaches and a detailed modelling framework." Australian Journal of Experimental Agriculture 45, no. 11 (2005): 1453. http://dx.doi.org/10.1071/ea04192.
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This paper illustrates the hydrological limitations and underlying assumptions of 4 catchment modelling approaches representing different generic classes of predictive models. These models are commonly used to estimate the impacts of land use and management change on stream flow and salinity regimes within a target region. Three approaches are based on a simple conceptual framework that assumes a single layer groundwater aquifer and requires minimal information and calibration (Zhang-BC2C, CAT1D-BC2C and LUCICAT), whereas the fourth approach (CAT3D) adopts a fully distributed highly parameterised catchment model capable of simulating complex multi-layered groundwater aquifer systems. All models were applied to the Gardiner subcatchment within the Goulburn–Broken region of Victoria, identified as a National Action Plan for Salinity priority subcatchment. Current condition simulation results were compared with observed stream flow and groundwater hydrograph data. Results show that the simple frameworks predicted whole-of-catchment mean annual salt and water yield with minimum parameterisation. The fully distributed framework produced similar catchment-scale responses to the simple approaches, but required more intensive input data and solution times. However, the fully distributed framework provides finer temporal and spatial scale information within the catchment. The more detailed models (such as CAT3D) also have the predictive capacity to assess the within-catchment dynamics at a range of scales and account for landscape position and complex surface/groundwater interactions. This paper concludes that the simple frameworks are useful for judging the whole-of-catchment impacts of broad-scale land use change on catchment water yields and salinity and therefore provide valuable tools for community engagement. However, the within-catchment dynamics are not well represented and particular care must be taken when applying such models in those catchments where the interaction between groundwater and surface features result in saturated areas that are disconnected from streams. Adoption of a distributed groundwater modelling environment similar to that of CAT3D provides higher spatial resolution relative to the lumped broad scale groundwater glow system (GFS) based parameterisation adopted by the BC2C rapid assessment approaches. The developers of the BC2C model acknowledge that such models are currently limited to upland local and intermediate groundwater flow systems. Given that the majority of land salinisation is located in regions dominated by intermediate and regional groundwater systems, this tool is not well suited to adequately model regional processes. In contrast, the CAT3D distributed groundwater models are likely to be applicable across a range of scales and provide the capacity to assess the trade offs between salinity recharge and discharge intervention strategies. We conclude that more complex models (e.g. CAT3D) are needed to identify at the land management scale (paddock/farm) cost effective land use and land management changes within the catchment to improve catchment health.
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Maini, N., A. Buchan, and S. Joseph. "Derivation of a salinity target for the Lower Murray Darling Valley." Water Science and Technology 48, no. 7 (October 1, 2003): 105–12. http://dx.doi.org/10.2166/wst.2003.0430.
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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.
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Aydin, Boran Ekin, Hugo Hagedooren, Martine M. Rutten, Joost Delsman, Gualbert H. P. Oude Essink, Nick van de Giesen, and Edo Abraham. "A Greedy Algorithm for Optimal Sensor Placement to Estimate Salinity in Polder Networks." Water 11, no. 5 (May 27, 2019): 1101. http://dx.doi.org/10.3390/w11051101.
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We present a systematic approach for salinity sensor placement in a polder network, where the objective is to estimate the unmeasured salinity levels in the main polder channels. We formulate this problem as optimization of the estimated salinity levels using root mean square error (RMSE) as the “goodness of fit” measure. Starting from a hydrodynamic and salt transport model of the Lissertocht catchment (a low-lying polder in the Netherlands), we use principal component analysis (PCA) to produce a low-order PCA model of the salinity distribution in the catchment. This model captures most of the relevant salinity dynamics and is capable of reconstructing the spatial and temporal salinity variation of the catchment. Just using three principal components (explaining 93% of the variance of the dataset) for the low-order PCA model, three optimally placed sensors with a greedy algorithm make the placement robust for modeling and measurement errors. The performance of the sensor placement for salinity reconstruction is evaluated against the detailed hydrodynamic and salt transport model and is shown to be close to the global optimum found by an exhaustive search with a RMSE of 82.2 mg/L.
10
Robertson, M. J., R. J. George, M. H. O'Connor, W. Dawes, Y. M. Oliver, and G. P. Raper. "Temporal and spatial patterns of salinity in a catchment of the central wheatbelt of Western Australia." Soil Research 48, no. 4 (2010): 326. http://dx.doi.org/10.1071/sr09126.
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Many estimates have been made of the future likely extent of salinity at regional and national scales in Australia; however, there are few detailed studies of changes in temporal and spatial patterns at catchment scale. This study was conducted in the Wallatin and O’Brien catchments in the low–medium rainfall zone of the central wheatbelt of Western Australia, where we examined the spatial trends in saline land over the last 18 years and related these to the likely rate and extent of future salinisation. The analysis showed that: (1) salinity has continued to expand post-1999 in landscape positions where there has been watertable rise and also in areas now at equilibrium even though rainfall has been below average; (2) increases in the area of salinity are still dominated by increases in the valley floor but there is now the emergence of many small, isolated outbreaks on the adjacent slopes; (3) widely available satellite-derived salinity maps (LandMonitor) derived in 1998 provide a reliable base-line for saline mapping but now underestimate the area of salt-affected land by 60%; (4) the trend in watertable levels and time since clearing and interactions with proximity to uncleared native vegetation provide reliable predictors of salinity risk; (5) episodic rainfall in areas of shallow watertables is proposed as a significant cause of the expansion in observed salinisation, even though some of this may be transient. These results are discussed in terms of management options for farmers and the likely long-term outlook for expansion of salinity in the catchment.
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L. Morgan, David, Dean C. Thorburn, and Howard S. Gill. "Salinization of southwestern Western Australian rivers and the implications for the inland fish fauna - the Blackwood River, a case study." Pacific Conservation Biology 9, no. 3 (2003): 161. http://dx.doi.org/10.1071/pc030161.
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Increasing salinities throughout southwestern Western Australia, facilitated by extensive land clearing, have compromised the region's highly endemic freshwater fishes. Salinization of the Blackwood River has resulted in the main channel and upper cleared catchment being dominated by estuarine and halotolerant teleosts. The non-halotolerant species are restricted to the forested non-saline tributaries of the lower catchment. Of the 12 943 fish (13 species) captured in 113 sites, the halotolerant introduced Mosquitofish Gambusia holbrooki was widespread and the most abundant, representing almost 52% of fish caught. The estuarine Western Hardyhead Leptatherina wallacei, which was also widespread throughout the main channel and upper catchment, was the next most abundant, representing ca. 24% of fish caught. Freshwater endemics represented ca. 23% of captures, with the Western Minnow Galaxias occidentalis and Western Pygmy Perch Edelia vittata accounting for most (i.e., ca. 20%). There were significant differences in teleost communities among the naturally vegetated, low salinity tributaries of the river compared with the main channel and upper cleared catchment. While the forested tributaries still contain populations of E. vittata, Nightfish Bostockia porosa and Mud Minnow Galaxiella munda, the elevated salinities in the upper reaches of the Blackwood River system appear to have caused a massive decline in, or extinction of, populations of these species. The protection of the region's unique freshwater teleosts relies on the preservation of their remaining habitat in both the uncleared catchments of the region and in the low salinity forested tributaries within largely cleared systems, such as those in the Blackwood River catchment.
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Jolly, I. D., D. R. Williamson, M. Gilfedder, G. R. Walker, R. Morton, G. Robinson, H. Jones, et al. "Historical stream salinity trends and catchment salt balances in the Murray - Darling Basin, Australia." Marine and Freshwater Research 52, no. 1 (2001): 53. http://dx.doi.org/10.1071/mf00018.
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This paper summarizes the results from a study of historical stream salinity trends and catchment salt balances within the Murray–Darling Basin, Australia. A broad analysis of stream salinization was necessary to assist prediction of the increase in the effect and extent of dryland salinity across the basin. The sparseness of the water-quality data necessitated the development of an innovative statistical trend technique that also allowed for the high autocorrelation of the stream salinity data which was often present.Results showed the spatial distribution of stream salinization and identified regions of concern. The salinization characteristics of four distinct geographical regions were identified by providing a spatial analysis of catchment salt balances and stream salinity trends. The salinization behaviour of each region was also related to distinct physical processes. The most significant rising trends and catchment salt output/input ratios were in the zone with 500–800 mm year–1 rainfall in the southern and eastern dryland region.
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Khan, Shahbaz, Muhammad Nadeem Asghar, Shahbaz Mushtaq, and Aftab Ahmad. "On-farm options for managing stream salinity in irrigation areas: an example from the Murray Darling Basin, Australia." Hydrology Research 39, no. 2 (April 1, 2008): 157–70. http://dx.doi.org/10.2166/nh.2008.036.
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Increasing salt concentration in tributaries from catchments and rising water tables are the prime contributor to environmental degradation of rivers, creeks, streams or other water bodies. This is especially true during periods of mid- and low stream flows in arid and semi-arid regions around the globe. Catchment scale studies suggest that management of stream salinity requires greater land use change than is economically viable. Therefore, rather than focusing on the opportunity cost of catchment scale interventions, exploring interventions that are potentially viable at farm scale could be an appropriate strategy for stream salinity management. This paper presents an analysis of alternative on-farm strategies, such as evaporation ponds and serial biological concentration of salts, aimed at developing an economically self-sustainable stream salinity management system for the Box Creek stormwater escape channel located in the Murray–Darling Basin (MDB), Australia. It is concluded that irrigation areas, with careful management of flows in tributary streams, may be able to play a role in safeguarding the Murray River against further salinisation from irrigation and dryland areas. The outcomes of this paper will be helpful, but not limited to, the MDB in addressing environmental, economic and social issues associated with management of salt concentration in tributaries.
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Acworth, R. I., and J. Jankowski. "Salt source for dryland salinity - evidence from an upland catchment on the Southern Tablelands of New South Wales." Soil Research 39, no. 1 (2001): 39. http://dx.doi.org/10.1071/sr99120.
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A detailed study involving drilling, geophysics, hydrogeochemistry, and groundwater monitoring over a 10-year period has been carried out at a small catchment south-east of Yass on the Southern Tablelands of New South Wales to investigate the source of salt causing dryland salinity. The catchment is within 2 km of the top of a regional groundwater and surface water divide and remains substantially tree covered. The investigations have found a highly heterogeneous distribution of salt, most of which is associated with swelling clay. Dispersion of this clay causes the surface features commonly associated with dryland salinity. There is no hydrogeochemical evidence to suggest evaporative or transpirative concentration of salt in the groundwater. The short flow path from the top of the catchment cannot provide a significant source of salt from bedrock weathering. An alternative model of salt accumulation is proposed with the salt imported into the catchment with silt during dust storms in the arid and windy conditions during the last glacial. The management implications of this model of salt distribution and the associated dryland salinity development are discussed.
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Kington, E. A., and D. J. Pannell. "Dryland salinity in the Upper Kent River catchment of Western Australia: farmer perceptions and practices." Australian Journal of Experimental Agriculture 43, no. 1 (2003): 19. http://dx.doi.org/10.1071/ea01058.
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Dryland salinity, resulting from extensive land clearing, has been increasingly recognised as a serious environmental and economic problem in Western Australia. Policy initiatives at the state and national level in Australia have attempted to influence farmers' choices of land management practices to reduce the threat of salinity. This study examines, for a particular catchment, what farmers' salinity management practices have been and are likely to be, how farmers view the salinity problem and its recommended treatments, and farmers' perceptions of why the salinity problem continues to worsen. We found that the farmers had high levels of knowledge about salinity and its treatment, although their perceptions appeared to be overly optimistic on a number of aspects of the problem. As a group they were highly uncertain about its extent and the rate of worsening, and they highlighted the complexity, modest effectiveness and relatively poor economic performance of available treatment options. It appears that the scale of salinity prevention practices in the catchment is insufficient for preventing ongoing increases in the area of saline land.
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Thorburn, P. J., I. J. Gordon, and S. McIntyre. "Soil and water salinity in Queensland: the prospect of ecological sustainability through the implementation of land clearing policy." Rangeland Journal 24, no. 1 (2002): 133. http://dx.doi.org/10.1071/rj02007.
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In Queensland, legislation has recently been enacted that outlines minimum standards for the retention of native vegetation in bioregions and prescribes Performance Requirements for the maintenance of biodiversity and ecological processes, and the prevention of land degradation. It also details Acceptable Solutions to satisfy the Performance Requirements. It this paper we analyse the links between science and action to determine whether the legislation and associated policy are likely to lead to sound management decisions being made for prevention of land and water salinity. We also compared the requirements for biodiversity protection relative to those for salinity control. For salinity (and biodiversity) the minimum standards and Acceptable Solutions in the legislation have a sound technical basis. The main challenge in implementing the salinity Performance Requirements will be provision of information required to assess salinity risk at appropriate scales. This information is: (1) salinity hazard assessment at catchment/regional scale planning scale; (2) technical information to support a sub-catchment scale implementation; (3) guidelines, procedures and local expertise for interpretation of salinity hazard at the property scale. In the process of assessing clearing applications there is no formal role for planners or decision makers at the sub-catchment level who could play an important role in coordinating information gathering for land managers developing clearing applications. There are also limited pathways for accessing relevant scientific information and expertise at an appropriate level to provide support for land managers. We suggest that this situation is likely to limit the successful implementation of the policy for preventing land and water salinity. The minimum standard of 30% retained vegetation would provide similar protection for biodiversity and salinity control at the bioregional level. In smaller areas (e.g. an individual property) however, there could be contrasting requirements for the retention of vegetation.
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Woodall, G. S., and C. J. Robinson. "Natural diversity of Santalum spicatum host species in south-coast river systems and their incorporation into profitable and biodiverse revegetation." Australian Journal of Botany 51, no. 6 (2003): 741. http://dx.doi.org/10.1071/bt02118.
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The commercially valuable root hemiparasite Santalum spicatum (R.Br.) A.DC. (sandalwood) once grew throughout the medium- to low-rainfall areas of the south-western agricultural region of Australia; however, this resource has been exhausted by over-exploitation and clearing for agriculture. There has been growing interest from the farming community and other investors in the development of a plantation Santalum spicatum industry in southern Western Australia. This study investigated the distribution of remnant S. spicatum within the Pallinup River catchment and assessed the risk of S. spicatum population decline due to salinity. The natural range of host species at different sites (river catchments) across the south coast was also investigated. Remnant populations of S.�spicatum within and adjacent to the Pallinup River catchment were small (1–70 trees) and highly fragmented. The risk of further population decline due to salinity was concluded to be small because remnant trees were generally growing in well drained, sandy soils that were elevated above (median 9 m) their immediate drainage line. Across the seven river catchments surveyed, S. spicatum occurred in a range of vegetation associations and parasitised numerous species (68) from a wide range of genera and families. The suite of species exploited varied within and between catchments. Thirty species, including most monocots and Myrtaceae, were not successfully parasitised. Remnant S. spicatum always occurred on well drained soil types that supported open-woodland or mallee–heath communities. Sandalwood plantations, supported by numerous individuals of a range of host species (10–40 species), were shown to be productive in terms of sandalwood growth. The scale of the developing sandalwood plantation industry is likely to be small and unlikely to cover large areas of catchments. Thus, this industry alone is unlikely to address the salinity crisis through broadscale recharge management. However, additional to on-site recharge reduction, biodiverse host plantations may improve the prospects for biodiversity and rivers in salinising landscapes through the protection and enhancement of natural biodiversity, creation of new habitat, conservation of plant species and by providing a commercial incentive to protect biodiversity.
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Hoey, D., M. Ahmed, and M. Littleboy. "Landscape Salinisation and Management: An Australian Perspective." Journal of Agricultural and Marine Sciences [JAMS] 7, no. 2 (June 1, 2002): 53. http://dx.doi.org/10.24200/jams.vol7iss2pp53-60.
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Australian landscapes are facing an increasing salinisation threat. It is estimated that 2.5 million hectares are affected by land salinisation, and this area is expected to triple by 2050. Federal and State governments have jointly developed a policy framework to address this issue, with each state refining their own salinity management strategies within this framework. Scientific assessment and modelling underpin these salinity management strategies, though socio-economic considerations are also important. Landscape salinity assessment techniques used in the Australian context are outlined, and examples of salinity hazard and recharge mapping at the landscape scale described. Current developments in both recharge assessment, and groundwater flow modelling in Australia are described, and the use of these models in underpinning state salinity strategic planning discussed. The salinity management ‘toolkit’ is discussed. The progression from initially applying engineering solutions to deal with the symptoms of salinisation; to dealing with the causes of salinisation; to developing an integrated catchment management approach; to including a stronger emphasis on market-based economic measures; and the importance of over-arching Catchment Blueprints, is described in detail.The application of knowledge and experience gained through the management of Australian land salinisation to other countries is discussed in the context of the salinity problem in the Sultanate of Oman.
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Weston, D. R., G. Quibell, and W. V. Pitman. "Towards managing catchment water utilisation for the Lake St Lucia ecosystem." Water Science and Technology 32, no. 5-6 (September 1, 1995): 95–101. http://dx.doi.org/10.2166/wst.1995.0571.
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Lake St Lucia is one of Africa's largest coastal lakes, and is one of South Africa's most important wetland ecosystems. However, like many ecosystems, it is under threat from increased demands for water in its catchment area. Reduced runoff primarily impacts on the salinity regime of the lake. At low lake levels there is a net inflow of seawater to the lake. Evaporation concentrates the salts, and lake salinities rise to several times that of seawater. In water periods, lake levels rise and there is a net outflow toward the sea. Under these conditions salinities are low. The lake therefore naturally experiences a range of salinities associated with wet and dry cycles. Increased water use in the catchment will, however, impact on this natural salinity regime. This paper introduces a suite of models which will be used to facilitate management of the water resources of the catchment. The preliminary work presented demonstrates the ability of the models to provide meaningful input into a catchment management decision-support system.
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Raidla, Valle, Enn Kaup, Sigrid Hade, Jüri Ivask, and Alvar Soesoo. "Geochemical Processes Controlling Ionic Composition of Water in the Catchments of Lakes Saana and Saanalampi in the Kilpisjärvi Area of North Scandinavia." Geosciences 9, no. 4 (April 16, 2019): 174. http://dx.doi.org/10.3390/geosciences9040174.
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The study focuses on chemical composition of stream and subsurface water in the catchments of two small arctic alpine lakes in the Kilpisjärvi area (northwest Finland). Differences and changes in chemical components of both water types are followed in order to detect spatial variability and impact of environmental factors. To achieve this, ion compositions of subsurface water and streams were measured at 12 sites in the catchments of Lakes Saana and Saanalampi during four years (2008–2010, and again in 2017). In the Lake Saanalampi catchment, the salinity of stream water (7.0 to 12.7 μS·cm−1) corresponded to that of snow. In the catchment of Lake Saana, however, the conductivity in stream water was much higher (40 to 220 μS·cm−1), connected mainly to the increase of SO42− and less with Mg2+ and Ca2+ contents, especially in the western part of the Saana catchment. These results demonstrate that arctic conditions do not preclude intense chemical weathering where conditions are favourable. Although chemical composition of the soil fluid does not match the geochemical signal from the local soil, rock composition, especially the presence of pyrite, is the main controller of chemical weathering rates of the rocks on the area. This supports earlier views that the character of precipitation mostly controls water chemistry of local lakes in the Kilpisjärvi area.
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Callow, J. Nikolaus, Matthew R. Hipsey, and Ryan I. J. Vogwill. "Surface water as a cause of land degradation from dryland salinity." Hydrology and Earth System Sciences 24, no. 2 (February 17, 2020): 717–34. http://dx.doi.org/10.5194/hess-24-717-2020.
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Abstract. Secondary dryland salinity is a global land degradation issue. Drylands are often less developed, less well instrumented and less well understood, requiring us to adapt and impose understanding from different hydro-geomorphological settings that are better instrumented and understood. Conceptual models of secondary dryland salinity, from wet and more hydrologically connected landscapes imposed with adjustments for rainfall and streamflow, have led to the pervasive understanding that land clearing alters water balance in favour of increased infiltration and rising groundwater that bring salts to the surface. This paper presents data from an intra-catchment surface flow gauging network run for 6 years and a surface-water–groundwater (SW–GW) interaction site to assess the adequacy of our conceptual understanding of secondary dryland salinity in environments with low gradients and runoff yield. The aim is to (re-)conceptualise pathways of water and salt redistribution in dryland landscapes and to investigate the role that surface water flows and connectivity plays in land degradation from salinity in low-gradient drylands. Based on the long-term end-of-catchment gauge, average annual runoff yield is only 0.14 % of rainfall. The internal gauging network that operated from 2007–2012 found pulses of internal water (also mobilising salt) in years when no flow was recorded at the catchment outlet. Data from a surface-water–groundwater interaction site show top-down recharge of surface water early in the water year that transitions to a bottom-up system of discharge later in the water year. This connection provides a mechanism for the vertical diffusion of salts to the surface waters, followed by evapo-concentration and downstream export when depression storage thresholds are exceeded. Intervention in this landscape by constructing a broad-based channel to address these processes resulted in a 25 % increase in flow volume and a 20 % reduction in salinity by allowing the lower catchment to more effectively support bypassing of the storages in the lower landscape that would otherwise retain water and allow salt to accumulate. Results from this study suggest catchment internal redistribution of relatively fresh runoff onto the valley floor is a major contributor to the development of secondary dryland salinity. Seasonally inundated areas are subject to significant transmission losses and drive processes of vertical salt mobility. These surface flow and connectivity processes are not only acting in isolation to cause secondary salinity but are also interacting with groundwater systems responding to land clearing and processes recognised in the more conventional understanding of hillslope recharge and groundwater discharge. The study landscape appears to have three functional hydrological components: upland, hillslope “flow” landscapes that generate fresh runoff; valley floor “fill” landscapes with high transmission losses and poor flow connectivity controlled by the micro-topography that promotes a surface–groundwater connection and salt movement; and the downstream “flood” landscapes, where flows are recorded only when internal storages (fill landscapes) are exceeded. This work highlights the role of surface water processes as a contributor to land degradation by dryland salinity in low-gradient landscapes.
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Kefford, Ben J., Carolyn G. Palmer, and Dayanthi Nugegoda. "Relative salinity tolerance of freshwater macroinvertebrates from the south-east Eastern Cape, South Africa compared with the Barwon Catchment, Victoria, Australia." Marine and Freshwater Research 56, no. 2 (2005): 163. http://dx.doi.org/10.1071/mf04098.
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Salinity is rising in many southern African and Australian rivers with unknown effects on aquatic organisms. The extent of spatial variation, at any scale, in salt tolerances of aquatic organisms is unknown, so whether data from one location is applicable elsewhere is also unknown. The acute tolerances (72-h median lethal concentration (LC50)) to sea salt of 49 macroinvertebrate taxa from the south-east Eastern Cape (SEEC), South Africa were compared with those of 57 species from the Barwon Catchment, Victoria, Australia. The mean LC50 values from both locations were similar (Barwon: 31 and SEEC: 32 mS cm−1) and less abundant (rare) taxa tended to be more tolerant than more abundant (common) taxa. There was, however, a greater range of LC50 values (5.5–76 mS cm−1) in the Barwon Catchment than in the SEEC (11–47 mS cm−1). The species sensitivity distribution (SSD) for SEEC taxa was bimodal whereas the Barwon Catchment’s SSD had a single peak. With few exceptions, members of an order had similar tolerances in both locations. The differences in SSD between locations were related to crustacean, odonate and non-arthropod relative richness. Although it is not ideal to extrapolate SSDs from one location to another, it may be reasonable to assume similar salinity tolerances among related taxa.
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Stolte, W. J., D. J. McFarlane, and R. J. George. "Flow systems, tree plantations, and salinisation in a Western Australian catchment." Soil Research 35, no. 5 (1997): 1213. http://dx.doi.org/10.1071/s96066.
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A lower hillslope in the Western Australian wheatbelt had become waterlogged and saline by 1981, when close-spaced rows of eucalypts were planted in blocks both in and adjacent to the discharge area and piezometers were established on the site. We analysed the trends in the piezometric heads and salinity concentrations over the period of record. We also modelled the hillslope profile using finite element analysis to determine the water flow mechanisms and to see how a change in vegetation in the upland area would affect the waterlogging and salinity. Piezometric levels under the trees decreased for the first 5 years after planting and then stabilised until 1991 when they started gradually decreasing again. The non-treed area between the plantation blocks remained unaffected until about 1991, when the levels there also started to decrease quite significantly, probably because of the trees. The trees therefore appear to have been effective and beneficial in the short to medium term. However, the salinity of the groundwater under the trees has increased significantly in the last 5 years, particularly where the tree density is highest. The continued flow of saline groundwater to the trees is believed to be increasing the salinity. It could not be expected that plantations of this type will maintain health and be able to control the excess water in such an hydrologic setting in the long term. Tree plantations on discharge areas are a short to medium term management strategy, not a solution, and the only way to control salinity in the long term is to plant vegetation species in the recharge areas that use all of the water that falls there. Modelling showed that only a small surplus of water over winter, in the order of 50 mm/year, caused the increased recharge and consequent salinisation. The modelling results also show that the surplus could be managed with an effective vegetation species (e.g. lucerne) with a rooting depth of about 1·5 m that would be able to transpire at least until early to mid summer.
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Hart, Barry T., P. S. Lake, J. Angus Webb, and Michael R. Grace. "Ecological risk to aquatic systems from salinity increases." Australian Journal of Botany 51, no. 6 (2003): 689. http://dx.doi.org/10.1071/bt02111.
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Salinity is a major problem in many regions of Australia, and is predicted to get considerably worse over the next 30–50 years. Most effort has focused on the terrestrial environment, and specifically on the loss of productive agricultural land. Increased salinity can also result in unwanted changes to aquatic ecosystems in rivers, streams and particularly wetlands.This paper first reviews the importance of assessing risks from salinity increases in a catchment context, and then introduces a disturbance–response conceptual model to assist with the understanding of such situations. Two factors are shown to be particularly important in assessing which freshwater systems will be most susceptible to increases in salinity—the location of the systems in the landscape, and the current ecological condition of the system. The resilience of an ecosystem to salinity disturbances is shown to be a useful concept which with further knowledge may be incorporated into risk-assessment approaches.The development of a new ecological risk assessment approach for assessing risks to aquatic systems in the Goulburn–Broken catchment from increases in salinity over the medium (20 years) and long (100 years) term is reported. The risks to the biota in Hughes Creek, a tributary of the Goulburn River, are assessed by using a probabilistic approach. Current salinity levels in the creek present a low risk to the biota.Finally, the paper addresses the challenge of making the ecological risk assessment method more quantitative by discussing the following two key aspects: how to better quantify the linkages between the key stressors and the biotic components, and how to better handle uncertainties.
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Bathgate, Andrew, Julian Seddon, John Finalyson, and Ron Hacker. "Managing catchments for multiple objectives: the implications of land use change for salinity, biodiversity and economics." Animal Production Science 49, no. 10 (2009): 852. http://dx.doi.org/10.1071/an09049.
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Policy developed for the management of natural resources in agricultural landscapes in recent years has emphasised the need for an integrated approach. Operationally however, natural resource objectives have been pursued independently with little consideration of the link between components of ecosystems and therefore the possibility of trade-offs between components. In the absence of this information, decision makers cannot adequately assess the cost-effectiveness of alternative strategies for improving the condition of the natural resource base. The aim of this study is to assess the extent of trade-offs between multiple catchment objectives viz. biodiversity, stream salinity, stream yield, salt load, sequestration of carbon and farm profit in the Little River Catchment in Central New South Wales. Seven scenarios describing different land use alternatives for the catchment were assessed using spatial datasets of catchment characteristics. A suite of models was used to determine the impact of land use change on these characteristics over a 50-year timeframe. The results of the analysis indicate that changes in farm production methods may deliver small improvements in some indicators of catchment health. However, significant improvements would require the establishment of large areas of woody perennials and this is only likely to occur with significant public investment, given the consequent large reduction in farm profit. Trade-offs between several catchment indicators were identified. Significantly the benefits of reducing stream salinity were outweighed by the losses resulting from reduced stream flow. Generally, the financial benefits of improving the indicators of resource condition were low relative to the investment required. It was concluded therefore that the environmental value of these improvements would need to be substantial to justify the investment.
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Taylor, R. J., and G. Hoxley. "Dryland salinity in Western Australia: managing a changing water cycle." Water Science and Technology 47, no. 7-8 (April 1, 2003): 201–7. http://dx.doi.org/10.2166/wst.2003.0690.
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Clearing of agricultural land has resulted in significant changes to the surface and groundwater hydrology. Currently about 10% of agricultural land in Western Australia is affected by dryland salinity and between a quarter and a third of the area is predicted to be lost to salinity before a new hydrological equilibrium is reached. This paper develops a general statement describing the changes to the surface and groundwater hydrology of the wheatbelt of Western Australia between preclearing, the year 2000 and into the future. For typical catchments in the wheatbelt it is estimated that average groundwater recharge and surface runoff have increased about tenfold when comparing the current hydrology to that preclearing. Saline groundwater discharge and flood volumes have also increased significantly. Saline groundwater discharge and associated salt load will probably double in the future in line with the predicted increase in the area of dryland salinity. In addition, future increases in the area of dryland salinity/permanent waterlogging will probably double the volumes in flood events and further increase surface runoff in average years. The outcomes of surface and groundwater management trials have been briefly described to estimate how the hydrology would be modified if the trials were implemented at a catchment scale. These results have been used to formulate possible integrated revegetation and drainage management strategies. The future hydrology and impacts with and without integrated management strategies have been compared.
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Greeff, G. J. "Ground-Water Contribution to Stream Salinity in a Shale Catchment, R.S.A." Ground Water 32, no. 1 (January 1994): 63–70. http://dx.doi.org/10.1111/j.1745-6584.1994.tb00612.x.
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Pannell, D. J. "Farm, food and resource issues: politics and dryland salinity." Australian Journal of Experimental Agriculture 45, no. 11 (2005): 1471. http://dx.doi.org/10.1071/ea04158.
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Political forces make it difficult to develop effective and efficient policies for dryland salinity. The politics of the day have had major influences on salinity and salinity-related policy, beginning with the clearing of land for agricultural development. Tensions affecting salinity policy include urban political power v. rural salinity; short-term politics v. long-term salinity; crisis-driven politics v. slow and inexorable salinity; simplistic and uniform political solutions v. complex and diverse salinity problems; the need for winners in politics v. the reality of losers from effective salinity policy; east v. west; and national v. state governments. These tensions will interact with our improving scientific knowledge of salinity and ongoing social and economic changes in rural areas to shape future salinity policies. Prospects for changes in salinity policy and outcomes over the next 10 years are suggested, including the following possibilities: more carefully targeted and site-specific investments in salinity prevention; the beginnings of success of current research and development efforts to develop profitable new plant-based systems for salinity management; ongoing debate about the appropriate role for catchment management bodies for in salinity management; greater attention to the problem of salinity impacts on biodiversity and infrastructure; reduced attention to market-based instruments for salinity; and ongoing changes in the economics of agriculture, timber and energy influencing salinity outcomes and, potentially, salinity policy.
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Naicker, S., and M. Demlie. "Environmental isotopic and hydrochemical characteristics of groundwater from the Sandspruit Catchment, Berg River Basin, South Africa." Water Science and Technology 69, no. 3 (November 20, 2013): 601–11. http://dx.doi.org/10.2166/wst.2013.751.
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The Sandspruit catchment (a tributary of the Berg River) represents a drainage system, whereby saline groundwater with total dissolved solids (TDS) up to 10,870 mg/l, and electrical conductivity (EC) up to 2,140 mS/m has been documented. The catchment belongs to the winter rainfall region with precipitation seldom exceeding 400 mm/yr, as such, groundwater recharge occurs predominantly from May to August. Recharge estimation using the catchment water-balance method, chloride mass balance method, and qualified guesses produced recharge rates between 8 and 70 mm/yr. To understand the origin, occurrence and dynamics of the saline groundwater, a coupled analysis of major ion hydrochemistry and environmental isotopes (δ18O, δ2H and 3H) data supported by conventional hydrogeological information has been undertaken. These spatial and multi-temporal hydrochemical and environmental isotope data provided insight into the origin, mechanisms and spatial evolution of the groundwater salinity. These data also illustrate that the saline groundwater within the catchment can be attributed to the combined effects of evaporation, salt dissolution, and groundwater mixing. The salinity of the groundwater tends to vary seasonally and evolves in the direction of groundwater flow. The stable isotope signatures further indicate two possible mechanisms of recharge; namely, (1) a slow diffuse type modern recharge through a relatively low permeability material as explained by heavy isotope signal and (2) a relatively quick recharge prior to evaporation from a distant high altitude source as explained by the relatively depleted isotopic signal and sub-modern to old tritium values.
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Gunneriusson, Lars, and Staffan Sjöberg. "Equilibrium Speciation Models for Hg, Cd, and Pb in the Gulf of Bothnia and its Catchment Area." Hydrology Research 22, no. 1 (February 1, 1991): 67–80. http://dx.doi.org/10.2166/nh.1991.0005.
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Equilibrium speciation models were established for Hg (II), Cd (II) and Pb (II) in bog-, river- and sea water having a composition corresponding to that of the Gulf of Bothnia (6 ‰ salinity). The calculations were performed using the computer program SOLGASWATER. The models were based on available thermodynamic data at 25°C and included the inorganic ligands OH−, Cl−, Br−, HPO42− and CO2 (aq). Furthermore, complex formation with organic substances originating from a bog water was considered, Mg (II) and Ca (II) were also included as competing cations. All water types were assumed to be oxic and in equilibrium with atmospheric carbon dioxide, 10−3.5 atm (32 Pa). The calculations showed that the speciation of Hg (II) and Pb (II) in bog and river waters is dominated by complexation with the organic substance, except for lead (II), where the Pb2+ -ion dominates at pH⩽5. In the Gulf of Bothnia, the chloro complexes HgCl2 and HgCl3− becomes prevailing as the salinity increases. Besides Pb2+, the species PbCl+ and PbCO3 become important upon increasing the salinity and pH. The dominating fraction of Cd (II) is Cd2+ in bog water, in river water and in waters of salinity lower than 4.5 ‰. With increasing salinity CdCl+ and CdCl2predominate.
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Bogdał, Andrzej, Andrzej Wałęga, Tomasz Kowalik, and Agnieszka Cupak. "Assessment of the Impact of Forestry and Settlement-Forest Use of the Catchments on the Parameters of Surface Water Quality: Case Studies for Chechło Reservoir Catchment, Southern Poland." Water 11, no. 5 (May 8, 2019): 964. http://dx.doi.org/10.3390/w11050964.
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The aim of the study was to determine the impact of natural and anthropogenic factors on the values of 22 quality indicators of surface waters flowing out of two small catchments differing in physiographic parameters and land use, in particular forest cover and urbanization of the area. The research was carried out in the years 2012–2014 at four measurement-control points located on the Chechło river and the Młoszówka stream (Poland), which are the main tributaries of the retention reservoir. Basic descriptive statistics, statistical tests, as well as cluster analysis and factor analysis were used to interpret the research results. The water that outflowed from the forestry-settlement catchment of the Młoszówka stream contained higher concentrations of total phosphorus, phosphates, nitrite, and nitrate nitrogen and salinity indicators than outflow from the Chechło river. Water from the Młoszówka stream was characterized by more favourable oxygen conditions. Higher oxygen concentration in the catchment influenced a large slope of the watercourse and thus higher water velocity, which is promoted by the mixed process. In the case of the forest catchment of the Chechło river, the water quality was generally better than in the Młoszówka stream, mainly in cases of total suspended solids TSS, total phosphorus TP, phosphates PO43−, total nitrogen TN, nitrite N–NO2−, nitrate N–NO3−, and salinity parameters. Despite it being a short section of the river taken into the study, favourable self-purification processes like mixed, nitrification, and denitrification were observed in its water. The research shows that forest areas have a positive effect on the balance of most substances dissolved in water, and natural factors in many cases shape the quality and utility values of surface waters on an equal footing with anthropogenic factors. In the case of a large number of examined parameters and complex processes occurring in water, the interpretation of the results makes it much easier by applying multivariate statistical methods.
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Bell, David T. "Australian Trees for the Rehabilitation of Waterlogged and Salinity-damaged Landscapes." Australian Journal of Botany 47, no. 5 (1999): 697. http://dx.doi.org/10.1071/bt96110.
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The revegetation of damaged agricultural landscapes requires a detailed knowledge of appropriate species and their adaptations to cope with the stresses of environments altered by humans. A range of Australian species has a role in the restoration of water and salt balances of catchments and can provide income diversity to agricultural properties damaged by increased frequencies of flooding, rising groundwaters and increased salinities. This review concentrates on the ecologically significant attributes of Australian woody species in waterlogged and saline habitats, and responses of species particularly suited to the restoration of water balance in cleared catchments. Australian catchments yield little water under natural vegetation, the trees and shrubs being especially resourceful in utilising much of the annual rainfall input. Replacing native, deep-rooted perennial species with annual crops always results in a net gain in catchment water. To redress these problems, cleared landscapes must be partially restored to tree and shrub cover to utilise the excess water remaining when crops are harvested or lie dormant over summer. Upland regions of restored landscapes should be planted to tree crops, particularly those that are luxuriant water users, of commercial value to farmers. Tree plantations for paper pulp, soft-wood timber and eucalypt oils are possibilities. Lowland sites in damaged catchments must be revegetated with trees which have waterlogging adaptations, such as aerenchyma, and tolerance to the products of anaerobic respiration. Areas of waterlogging that are additionally affected by excess salts must have exceptional trees. Australia has a number of native species which are well suited to survive these conditions, produce biomass and utilise excess water, while restricting or coping with the uptake of over-abundant salts. Most tolerant Australian species have a range of anatomical, morphological and physiological attributes to contribute to these adaptive qualities. This review highlights some of these features and describes various combinations that are successful. Australia now has a range of genotypes to bring to bear in the battle to rehabilitate landscapes damaged by disruption of the soil–salt–water balance. Only by redressing these problems can we ensure that future generations will have land capable of retaining economic value and producing potable water.
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Cowie, B. A., C. M. Thornton, and B. J. Radford. "The Brigalow Catchment Study: I. Overview of a 40-year study of the effects of land clearing in the brigalow bioregion of Australia." Soil Research 45, no. 7 (2007): 479. http://dx.doi.org/10.1071/sr07063.
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This paper describes a long-term, paired-catchment study, its broad findings, and considerations for future resource management of brigalow lands in north-eastern Australia. The Brigalow Catchment Study (BCS) commenced in 1965 with a pre-clearing calibration phase of 17 years to define the hydrology of 3 adjoining catchments (12–17 ha). After 2 catchments were cleared in 1982, 3 land uses (brigalow forest Acacia harpophylla, cropping, and grazed pasture) were monitored for water balance, resource condition and productivity, providing information for scientific understanding and resource management of the major land uses of the brigalow bioregion. In addition, this paper draws upon several project reviews to highlight the value of the BCS as an ‘outdoor laboratory’, its data resource, and to reflect on the study’s scientific rigor to support present and future value. An assessment of the BCS against national and international attributes of best practice for long-term studies showed the study to rate highly in aspects of design, implementation, monitoring, and data management, and moderately in formal publication, strategic management, and networking. The literature shows that Brigalow Catchment Study is the longest paired-catchment study in Australia, and continues to sample the interactions between climate, soils, water, land use, and management. Finally, this paper provides the context for component-specific papers on changes in hydrology, productivity, and salt balance. Results from the study to date include: a doubling of runoff after clearing, a reduction in wheat yield by more than 60% over 20 years, a halving of pasture availability 3 years after clearing, a decline in cattle liveweight gain of 4 kg/ha.year over an 8-year period with a constant stocking rate, and the leaching of 60% of the root-zone (0–1.5 m) chloride after clearing for cropping. Unanticipated applications of the data from the study include: (i) a crucial set of soil samples for calibration of the RothC soil carbon model used to estimate Australia’s soil carbon emissions; and (ii) estimates of deep drainage as a basis for salinity risk assessment in the region.
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Beatty, Stephen J., David L. Morgan, Mahmoud Rashnavadi, and Alan J. Lymbery. "Salinity tolerances of endemic freshwater fishes of south-western Australia: implications for conservation in a biodiversity hotspot." Marine and Freshwater Research 62, no. 1 (2011): 91. http://dx.doi.org/10.1071/mf10100.
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Secondary salinisation represents an important threat to terrestrial and aquatic habitats throughout the world. In south-western Australia, widespread salinisation of waterways has caused large range reductions in the highly endemic freshwater fish fauna. We hypothesised that differences in the distributions of three fish species within the salinised Blackwood River would be related to their salinity tolerances. Galaxias occidentalis was widespread throughout the catchment, whereas Nannoperca vittata was restricted to the main channel and freshwater tributaries of the lower catchment, and Nannatherina balstoni was restricted to those tributaries and a perennial section of the main channel that received a considerable amount of fresh groundwater. Acute salinity tolerances (Effect Concentrations) of G. occidentalis and N. vittata were similar (EC50 ∼14.6 g L–1), but significantly greater than that of N. balstoni (EC50 ∼8.2 g L–1). The greater geographical range of G. occidentalis, compared with N. vittata, may be a consequence of the dispersal capability of the former species, and the lower salinity tolerance of N. balstoni contributes to its highly restricted range. The findings demonstrate that secondary salinisation has greatly impacted these freshwater fishes, and fresh groundwater refuges, predicted to decrease due to reduced rainfall, appear crucial in maintaining remnant populations.
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Blackmore, D. J. "Murray-Darling Basin Commission: a case study in integrated catchment management." Water Science and Technology 32, no. 5-6 (September 1, 1995): 15–25. http://dx.doi.org/10.2166/wst.1995.0548.
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This paper describes the Australian Murray-Darling basin experience in integrated catchment management, what has been achieved and what remains to be done. The basin water is shared by three states, but falls under the jurisdiction of four governments, that of the Commonwealth as well as the State governments. The critical development in recent years at the political and bureaucratic level was the establishment of a three-tier management structure that allows common interests to be developed, discussed, resolved and implemented. Two main problems had to be resolved before significant co-operative action could take place, namely the issues of water sharing between the states and the sharing of costs associated with Murray River salinity. A framework Salinity and Drainage Strategy was developed to address this, and is described. This paper also describes the Natural Resources Management Strategy, the cornerstone of efforts to sustain the natural resources of the basin. The strategy emphasises community participation and empowerment. The problems identified, strategic aims to address these problems and the role of community action are detailed.
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Azad, M. A. Samad, and Tihomir Ancev. "Economics of Salinity Effects from Irrigated Cotton: An Efficiency Analysis." Water Economics and Policy 02, no. 01 (March 2016): 1650002. http://dx.doi.org/10.1142/s2382624x16500028.
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Using an environmentally adjusted performance measurement the study evaluates the tradeoffs between the benefits derived from irrigated cotton enterprises and its associated environmental damages. Deep drainage, which adds to the aquifer recharge and thereby contributes to salinization, is treated as an environmentally detrimental output. The analysis includes data collected from a sample of 53 observations in the Mooki Catchment located in northern New South Wales, Australia. Environmentally adjusted efficiency of cotton enterprises is estimated using the environmental performance index (EPI) and relative efficiency rankings are determined for each of the considered cotton areas in the catchment. The findings reveal that environmentally adjusted efficiency of irrigated cotton is within an acceptable range (more than 60% of observations have an EPI efficiency score of greater than 5). The efficiency variation among the observations based on hydrological response units (HRUs) can be attributed to a number of reasons including physical factors (i.e., soil quality, topography), type of irrigation technology used, and other environmental factors. For instance, the overall efficiencies of downstream HRUs are higher than that of upstream HRUs. Therefore, biophysical characteristics of an area need to be incorporated in the efficiency model. With the identification of the most and least efficient cotton irrigation areas in the region, policymakers can construct a relative ranking to best determine policy directions in order to take a more targeted approach towards salinity mitigation.
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McCartney, Matthew, Christopher Scott, Jeroen Ensink, BinBin Jiang, and Trent Biggs. "Salinity Implications of Wastewater Irrigation in the Musi River Catchment in India." Ceylon Journal of Science (Biological Sciences) 37, no. 1 (June 16, 2009): 49. http://dx.doi.org/10.4038/cjsbs.v37i1.495.
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Poulsen, David L., Craig T. Simmons, Corinne Le Galle La Salle, and Jim W. Cox. "Assessing catchment-scale spatial and temporal patterns of groundwater and stream salinity." Hydrogeology Journal 14, no. 7 (August 24, 2006): 1339–59. http://dx.doi.org/10.1007/s10040-006-0065-9.
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Williams, John, E. N. Bui, E. A. Gardner, Mark Littleboy, and M. E. Probert. "Tree clearing and dryland salinity hazard in the Upper Burdekin Catchment of North Queensland." Soil Research 35, no. 4 (1997): 785. http://dx.doi.org/10.1071/s96083.
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This paper provides experimental data on the effect of tree clearing, introduction of perennial Stylosanthes based pastures, and the use of native grasses on the water balance of a red earth soil in the Upper Burdekin Catchment near Charters Towers. The water balance simulation models SWIM and PERFECT are used to extend the results and estimate deep drainage for this and other soils in this tropical environment. The analysis illustrates that the soil/climate interaction in the wet/dry tropics has a similarity with the winter-dominant rainfall zone where vegetation change can substantially increase deep drainage beyond the root-zone. Salt distribution in the soil/landscapes of the Upper Burdekin suggests that there is a salinity hazard, should a significant shift in the water balance occur as a result of tree clearing. Therefore, in the Upper Burdekin Catchment of North Queensland, indiscriminate tree clearing is a hazardous form of land management and should only proceed after the risks of dryland salinity have been evaluated and shown to be negligible.
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Young, Michael D., and Darla Hatton MacDonald. "An opportunity to improve water trading in the South East Catchment of South Australia." Water Policy 5, no. 2 (April 1, 2003): 127–46. http://dx.doi.org/10.2166/wp.2003.0008.
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This paper outlines how an area-based water allocation system for irrigating crops could be converted to a system of shares, structured so as to allow the development of a low cost trading market for water and salinity shares. It stresses the need for separation of entitlements of water from land and the separation of water rights into their various components. By moving to this type of allocation system, combined with some safeguard provisions, trade in groundwater could be facilitated in the South East Water Catchment located in the State of South Australia. Separation of salinity and other environmental impacts from water volume trading will allow market assessment of highest and best use to include consideration of environmental impacts. Although the focus of the paper is on groundwater allocation and management, the principles and concepts outlined are applicable to surface water systems.
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Krishnakumar, A., Revathy Das, and Saranya Puthalath. "Assessment of the quality of water resources in coastal urban lands of two small catchment rivers, Southwest India." Management of Environmental Quality: An International Journal 28, no. 3 (April 10, 2017): 444–59. http://dx.doi.org/10.1108/meq-01-2015-0002.
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Purpose The purpose of this paper is to assess the ground water quality and salinity issues in the fast developing coastal urban lands of two river basins of Thiruvananthapuram district, Kerala, South India. Design/methodology/approach In order to address the water quality of the basins, field sampling was conducted and the samples were analysed in the laboratory. A comparison with water quality standards was also made and the interpretations of the results were done using GIS and statistical tools. Findings The values of conductivity, chlorides and salinity show that the coastal areas of Neyyar and Karamana basins are severely affected by salinity intrusion in addition to the pollution problems. More than 90 per cent of the samples are with hardness lower than 100 mg/l. About 70 per cent of the study area is with calcium concentrations lower than 25 mg/l. The content of sulphate and magnesium in Poovar and Poonthura coastal stretches is found to be higher compared to other regions. Originality/value Since not much work has been published from the study area on these aspects, the hydrochemical characterization is a very important in deciphering the quality of ground water for its proper management. The water quality evaluation and salinity intrusion studies are very important for the future planning and development of this area.
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Alexander, J. K., A. M. Roberts, and D. J. Pannell. "Victorian catchment management approaches to salinity: learning from the National Action Plan experience." Australasian Journal of Environmental Management 17, no. 1 (March 2010): 45–52. http://dx.doi.org/10.1080/14486563.2010.9725248.
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Crawford, M. H., K. M. Williams, A. J. W. Biggs, and E. Dafny. "Salinity risk assessment of an irrigation development using treated coal seam gas water in the Condamine River catchment." Soil Research 59, no. 1 (2021): 44. http://dx.doi.org/10.1071/sr19375.
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All irrigation developments inherently carry a salinity risk, due to an unavoidable change in the water and salt balance. The time frame in which either land or water salinity will develop is driven by the ability of the landscape to absorb the change of water and salt supplied. Factors that influence this are landscape attributes, such as the size of the unsaturated zone and its properties (permeability and drainage), management considerations (land-use changes, water application rate and crop water use) and climate variability (temperature and rainfall). This study assessed the risk of secondary salinity expression occurring in an irrigation area in the Condamine-Balonne catchment in southern inland Queensland, Australia. The objectives were to (1) define the depth, size and properties of the unsaturated zone and regolith, (2) define deep drainage rates for past, present and future land uses and (3) assess this information to calculate the risk that groundwater table rise may result in surface salinity expression. Data collected during field investigations was used to conceptualise the regolith architecture, undertake hydrogeological modelling, estimate the available moisture storage capacity of the unsaturated zone and model paddock deep drainage characteristics. The work identified that irrigation-induced deep drainage had started to mobilise salt stores in the unsaturated zone. It also identified connectivity between land management and salt discharges into the Condamine River. As the water supply for the scheme is scheduled to continue until 2030, there is a clear risk of the unsaturated zone moisture storage capacity being exceeded, leading to both land and surface water salt expressions.
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Spears, Bryan M., James E. Saunders, Irvine Davidson, and David M. Paterson. "Microalgal sediment biostabilisation along a salinity gradient in the Eden Estuary, Scotland: unravelling a paradox." Marine and Freshwater Research 59, no. 4 (2008): 313. http://dx.doi.org/10.1071/mf07164.
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Microalgal biostabilisation of cohesive sediments via the production of extracellular polymeric substances (EPS) has been well documented in intertidal ecosystems and represents a key ecosystem service with respect to the regulation of sediment transport. However, recent ecosystem comparison studies have uncovered a paradox in which sediment stability is commonly observed to be lower in freshwater ecosystems (compared with estuarine ecosystems) even though sediment EPS concentrations and microalgal biomass are high. Using a combination of freshwater and estuarine field and mesocosm techniques, the relative and interactive roles of salinity and the production of EPS (carbohydrate concentration) by benthic microalgae in the mediation of sediment stability in the Eden River catchment (river, mudflat and saltmarsh) were assessed. Sediment stability apparently increased with salinity from river (42.43 N m–2 surface stagnation pressure; salinity 0) to mudflat (98.65 N m–2; salinity 25) to saltmarsh (135.48 N m–2; salinity 46). The opposite trend was observed in sediment chlorophyll a and carbohydrate concentrations, indicating that salinity is the main variable driving sediment stability across the ecosystems under moderate EPS concentrations. Observations from mesocosm experiments highlighted the individual and combined importance of salinity and EPS in biostabilisation, with the largest increase in sediment stability observed following combined additions (25-fold increase compared with the control). The biogeochemical processes responsible, and their role in buffering phosphorus transport across the freshwater–saltwater transitional zone, are discussed.
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Baldwin, Douglas, Salvatore Manfreda, Henry Lin, and Erica A. H. Smithwick. "Estimating Root Zone Soil Moisture Across the Eastern United States with Passive Microwave Satellite Data and a Simple Hydrologic Model." Remote Sensing 11, no. 17 (August 27, 2019): 2013. http://dx.doi.org/10.3390/rs11172013.
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Root zone soil moisture (RZSM) affects many natural processes and is an important component of environmental modeling, but it is expensive and challenging to monitor for relatively small spatial extents. Satellite datasets offer ample spatial coverage of near-surface soil moisture content at up to a daily time-step, but satellite-derived data products are currently too coarse in spatial resolution to use directly for many environmental applications, such as those for small catchments. This study investigated the use of passive microwave satellite soil moisture data products in a simple hydrologic model to provide root zone soil moisture estimates across a small catchment over a two year time period and the Eastern U.S. (EUS) at a 1 km resolution over a decadal time-scale. The physically based soil moisture analytical relationship (SMAR) was calibrated and tested with the Advanced Microwave Scanning Radiometer (AMSRE), Soil Moisture Ocean Salinity (SMOS), and Soil Moisture Active Passive (SMAP) data products. The SMAR spatial model relies on maps of soil physical properties and was first tested at the Shale Hills experimental catchment in central Pennsylvania. The model met a root mean square error (RMSE) benchmark of 0.06 cm3 cm−3 at 66% of the locations throughout the catchment. Then, the SMAR spatial model was calibrated at up to 68 sites (SCAN and AMERIFLUX network sites) that monitor soil moisture across the EUS region, and maps of SMAR parameters were generated for each satellite data product. The average RMSE for RZSM estimates from each satellite data product is <0.06 cm3 cm−3. Lastly, the 1 km EUS regional RZSM maps were tested with data from the Shale Hills, which was set aside for validating the regional SMAR, and the RMSE between the RZSM predictions and the catchment average is 0.042 cm3 cm−3. This study offers a promising approach for generating long time-series of regional RZSM maps with the same spatial resolution of soil property maps.
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Asante-Annor, Asare, P. N. Bewil, and D. Boateng. "Evaluation of Groundwater Suitability for Irrigation in the Lambussie-Karni District of Ghana." Ghana Mining Journal 18, no. 1 (June 20, 2018): 9–19. http://dx.doi.org/10.4314/gm.v18i1.2.
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The populace of the Lambussie-Karni District are mainly farmers who have resorted to the use of groundwater for irrigation during the dry season because of long drought and inadequate surface water bodies. The temporal variation of the groundwater quality for irrigation in the District was assessed using sixteen boreholes. Richard Plot indicates that groundwater in the study area is within the low salinity to low sodium hazard and medium salinity to low sodium hazard class. Wilcox Plot shows groundwater to be within excellent to good class in the catchment. Irrigation water quality index (IWQI) map was also developed to determine precisely the degree and areal extent of groundwater suitability for irrigation. ArcGIS 10.1 was used to generate thematic maps for sodium adsorption ratio (SAR), residual sodium carbonate (RSC), permeability index (PI), sodium percentage (Na %), HCO3-, pH and electrical conductivity. The results were compared to Food and Agricultural Organisations (FAO) standard guidelines. An IQWI map for the Lambussie- Karni District shows that groundwater is generally suitable for irrigation, about 24.57 % of the district will require crops which can tolerate high amount of salts. A percentage (39.82 %) of the catchment has groundwater, which is highly suitable for crops which are least resistant to salt. Keywords: Groundwater Suitability; Irrigation Water Quality; SAR; IWQI Map; Lambussie-Karni District
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Hirst, A. J., K. Giri, D. Ball, and R. S. Lee. "Determination of the physical drivers of Zostera seagrass distribution using a spatial autoregressive lag model." Marine and Freshwater Research 68, no. 9 (2017): 1752. http://dx.doi.org/10.1071/mf16252.
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Seagrass mapping has become a key tool in understanding the causes of change in seagrass habitats. The present study demonstrates a method for examining relationships between seagrass habitat polygons and environmental data generated by hydrodynamic, wave, catchment and dispersion models. Seagrass abundance data are highly spatially autocorrelated and this effect was corrected using a spatially simultaneous autoregressive lag model (SSARLM). The physical processes that determine the spatial distribution of seagrass in Port Phillip Bay, Australia, were investigated by examining the links between seagrass distribution and abundance and broadscale hydrodynamic (waves, currents), physical (light, depth, salinity and temperature) and catchment (nutrient and suspended sediment concentrations) processes. The SSARLM indicated that the distribution of Zostera spp. meadows is principally constrained by two physical thresholds, namely, wave height or exposure and light. The former excludes seagrasses from colonising wave-exposed coastlines, whereas the latter directly determines the depth profile of seagrasses through its influence on light availability. In total, 95% of all seagrass occurred within grid cells with a mean significant wave height of <0.38m and a mean percentage irradiance of >33% surface levels. By comparison, variation in water quality, represented by variables such as modelled total nitrogen, suspended solids or salinity, had little influence on seagrass distribution.
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Nguyen, Viet Tung, Karina Yew-Hoong Gin, Martin Reinhard, and Changhui Liu. "Occurrence, fate, and fluxes of perfluorochemicals (PFCs) in an urban catchment: Marina Reservoir, Singapore." Water Science and Technology 66, no. 11 (December 1, 2012): 2439–46. http://dx.doi.org/10.2166/wst.2012.475.
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A study was carried out to characterize the occurrence, sources and sinks of perfluorochemicals (PFCs) in the Marina Catchment and Reservoir, Singapore. Salinity depth profiles indicated the reservoir was stratified with lower layers consisting of sea water (salinity ranging from 32 to 35 g L−1) and a brackish surface layer containing approximately 14–65% seawater. The PFC mixture detected in catchment waters contained perfluoroalkyl carboxylates (PFCAs), particularly perfluorooctanoate (PFOA), perfluorohexanoate (PFHpA), perfluorooctane sulfonate (PFOS) and PFC transformation products. PFC concentrations in storm runoff were generally higher than those in dry weather flow of canals and rivers. PFC concentration profiles measured during storm events indicated ‘first flush’ behavior, probably because storm water is leaching PFC compounds from non-point sources present in the catchment area. Storm runoff carries high concentrations of suspended solids (SS), which suggests that PFC transport is via SS. In Marina Bay, PFCs are deposited in the sediments along with the SS. In sediments, the total PFC concentration was 4,700 ng kg−1, approximately 200 times higher than in the bottom water layers. Total perfluoroalkyl sulfonates (PFSAs), particularly PFOS and 6:2 fluoro telomer sulfonate (6:2 FtS) were dominant PFCs in the sediments. PFC sorption by sediments varied with perfluorocarbon chain length, type of functional group and sediment characteristics. A first approximation analysis based on SS transport suggested that the annual PFC input into the reservoir was approximately 35 ± 12 kg y−1. Contributions of SS, dry weather flow of river/canals, and rainfall were approximately 70, 25 and 5%, respectively. This information will be useful for improving strategies to protect the reservoir from PFC contamination.
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Bhusal, Jivan, and Prakash Gyawali. "Water quality of springs in Badigad Catchment, Western Nepal." Bulletin of the Department of Geology 18 (January 23, 2017): 67–74. http://dx.doi.org/10.3126/bdg.v18i0.16458.
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Population growth and intense agricultural activities in Nepal has caused substantial increase in demand for fresh water. As there is limited access to surface water in most parts of the country, groundwater and springs are the principal water sources for irrigation and drinking purposes in the Terai and hilly region, respectively. The present study carries out the water quality analysis of 30 spring samples in the Badigad Catchment from Gulmi and Baglung Districts. The study was made to analyse suitability of spring waters of the Badigad Catchment for irrigation and drinking purposes. The physiochemical parameters were analysed using standard methods in the site and laboratory. Average value for pH of the sample was 7.8 with conductivity value ranging from 630 to 1500 micro Siemens/cm. The bicarbonate alkalinity ranges from 140 to 350 mg/L, indicating a medium salinity hazard in the catchment. The water in the catchment was found to be moderately hard with an average of 75mg/L CaCO3 hardness. Nitrate, sulphate, ammonia, chloride, fluoride and sodium absorption ratio were found to be <0.1mg/L, <1mg/L, <1.5mg/L, 3mg/L, 1mg/L and <2, respectively in all samples. Iron content in the water was also below the permissible limits in some samples and not available in some samples. Thus, the spring water in Badigad Catchment is suitable for drinking and irrigation purposes.Bulletin of the Department of Geology, Vol. 18, 2015, pp. 67-74
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Curtis, Allan, Michael Lockwood, and Jacinta MacKay. "Exploring Landholder Willingness and Capacity to Manage Dryland Salinity in the Goulburn Broken Catchment." Australasian Journal of Environmental Management 8, no. 2 (January 2001): 79–90. http://dx.doi.org/10.1080/14486563.2001.10648516.
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