Sediment yields and turbidity records from small upland subcatchments in the Warragamba Dam Catchment, southern New South Wales

Soil Research ◽  
2002 ◽  
Vol 40 (4) ◽  
pp. 557 ◽  
Author(s):  
J. L. Armstrong ◽  
D. H. Mackenzie

Accelerated rates of soil erosion, following European settlement in Australia, pose a major threat to river ecosystems and water supply storages with agricultural catchments, such as Warragamba Dam (the main water supply dam for Sydney). Sediment yields from 1988 to 1999 have been determined by stream monitoring for 6 small grazing catchments located near Goulburn in southern New South Wales, in the outer Warragamba catchment. Average specific sediment yields were 0.07 t/ha.year from 3 small catchments of around 10 ha, where the drainage lines were not continuously gullied, and the drainage lines were undisturbed. Sediment yields from larger gullied catchments of 29, 52, and 510 ha were at least an order of magnitude higher than from the ungullied catchments at around 1 t/ha.year. Gullies continue to be the dominant source of sediment from these subcatchments despite indications that yields from gullies in the Southern Tablelands are much less than in the first few decades following settlement and are gradually declining as gullies move towards a stable vegetated state. Measured sediment yields from this study are comparable with yields for southern New South Wales determined using other methods, such as radionuclide and farm dam survey techniques. The impact of soil conservation works, such as sediment trapping and grade stabilisation works, on sediment yields can be mixed depending on the activity of the gully being treated and the mobility of the bed sediments. Turbidity levels from runoff events from the gullied catchments were an order of magnitude higher than from the ungullied catchments. For the Warragamba catchment turbidity levels are scale dependent; at the farm paddock scale turbidities are generally low where the land use is grazing, they increase dramatically at the subcatchment scale where active gullies dominate the drainage network, and then drop back again at the large river catchment scale. Turbidity is positively correlated with sediment concentration, so works that reduce sediment loads will also reduce the turbidity of water leaving the subcatchment. However, the link between high turbidity levels in small upland catchments and downstream water quality in large complex river basins is tenuous.

1996 ◽  
Vol 36 (3) ◽  
pp. 299 ◽  
Author(s):  
TS Andrews ◽  
RDB Whalley ◽  
CE Jones

Inputs and losses from Giant Parramatta grass [GPG, Sporobolus indicus (L.) R. Br. var. major (Buse) Baaijens] soil seed banks were quantified on the North Coast of New South Wales. Monthly potential seed production and actual seed fall was estimated at Valla during 1991-92. Total potential production was >668 000 seeds/m2 for the season, while seed fall was >146000 seeds/m2. Seed fall >10000 seeds/m2.month was recorded from January until May, with further seed falls recorded in June and July. The impact of seed production on seed banks was assessed by estimating seed banks in the seed production quadrats before and after seed fall. Seed banks in 4 of the 6 sites decreased in year 2, although seed numbers at 1 damp site increased markedly. Defoliation from mid-December until February, April or June prevented seed production, reducing seed banks by 34% over 7 months. Seed banks in undefoliated plots increased by 3300 seeds/m2, although seed fall was estimated at >114 000 seeds/m2. Emergence of GPG seedlings from artificially established and naturally occurring, persistent seed banks was recorded for 3 years from bare and vegetated treatment plots. Sown seeds showed high levels of innate dormancy and only 4% of seeds emerged when sown immediately after collection. Longer storage of seeds after collection resulted in more seedlings emerging. Estimates of persistent seed banks ranged from 1650 to about 21260 seeds/m2. Most seedlings emerged in spring or autumn and this was correlated with rainfall but not with ambient temperatures. Rates of seed bank decline in both bare and vegetated treatment plots was estimated by fitting exponential decay curves to seed bank estimates. Assuming no further seed inputs, it was estimated that it would take about 3 and 5 years, respectively, for seed banks to decline to 150 seeds/m2 in bare and vegetated treatments.


1995 ◽  
Vol 37 (2) ◽  
pp. 203-217 ◽  
Author(s):  
Michael O'Donnell

Decentralizing industrial relations within New South Wales is a central recom mendation of the Niland Green Paper (1989). Decentralism also represents the cornerstone of the New South Wales government's industrial relations reform agenda enshrined in the New South Wales Industrial Relations Act 1991. To date there has been little analysis of the impact o f this legislative change on industrial relations in the New South Wales public sector. This paper provides a case study that examines the degree to which responsibility for bargaining has been devolved within the Parks and Gardens of the New South Wales Ministry for the Environ ment. It argues that, in contrast to the rhetoric of the New South Wales Act, the central agency presiding over the introduction of enterprise bargaining in the public sector, the Public Employment and Industrial Relations Authority; has been reluctant to delegate responsibility to parties in the workplace.


2021 ◽  
Vol 55 (1) ◽  
pp. 84-94
Author(s):  
Andrea Wallace ◽  
Brian Dollery

Abstract In response to the COVID-19 pandemic, the New South Wales (NSW) government ordered the closure of all municipal libraries in order to limit the impact of the contagion. As a result, 372 public libraries in NSW ceased operation on the 23rd March 2020. While the closure of public libraries will undoubtedly contribute to restricting the spread of the coronavirus, given the pivotal role played by municipal libraries in local communities, as well as the special characteristics of library patrons, it will have other negative consequences. In this paper we consider the impact of the closure of municipal libraries in NSW from two perspectives: (a) its effect on the fiscal circumstances of local authorities and (b) its impact on the spread of the corona contagion as well as its broader effects on local community wellbeing. We conclude that rather than complete closure, partial constraints on library use should have been considered.


2021 ◽  
Author(s):  
Timothy Lahmers ◽  
Sujay Kumar ◽  
Aubrey Dugger ◽  
David Gochis ◽  
Joseph Santanello

<div> <p>In late 2019 widespread wildfires impacted much of the New South Wales province in south east Australia, and this loss of vegetation contributed to increased surface runoff and consequently major flooding caused by extreme rainfall by early 2020. The recently developed NASA LIS/WRF-Hydro system enables the data assimilation (DA) capabilities of the NASA Land Information System (LIS) and the surface hydrological modeling capabilities of the WRF-Hydro model to be combined in a single model architecture. Combining the DA capabilities of the LIS system with WRF-Hydro, which has been used for both research and operational hydrologic simulations, we investigate the impacts of vegetation DA on the simulated floods in several basins across New South Wales, with varying degrees of burn severity from the 2019 fires. We also consider the impacts of the wildfires, as realized through vegetation DA on water partitioning and the surface energy budget, which both have implications for L-A interactions. For DA, we utilize the leaf area index retrievals from MODIS and vegetation optical depth from SMAP. For the present study, we will quantify the impact of the changes to the landscape brought about by the wildfires on hydrologic response, including flood severity, which would not be possible without the DA capabilities of the LIS/WRF-Hydro system.</p> </div>


2020 ◽  
pp. emermed-2019-208958 ◽  
Author(s):  
Nicola Wing Young Man ◽  
Roberto Forero ◽  
Hanh Ngo ◽  
David Mountain ◽  
Gerard FitzGerald ◽  
...  

IntroductionDelayed handover of emergency medical services (EMS) patients to EDs is a major issue with hospital crowding considered a primary cause. We explore the impact of the 4-hour rule (the Policy) in Australia, focusing on ambulance and ED delays.MethodsEMS (ambulance), ED and hospital data of adult patients presenting to 14 EDs from 2002 to 2013 in three jurisdictions were linked. Interrupted time series ‘Before-and-After’ trend analysis was used for assessing the Policy’s impact. Random effects meta-regression analysis was examined for associations between ambulance delays and Policy-associated ED intake, throughput and output changes.ResultsBefore the Policy, the proportion of ED ambulances delayed increased between 1.1% and 1.7% per quarter across jurisdictions. After Policy introduction, Western Australia’s increasing trend continued but Queensland decreased by 5.1% per quarter. In New South Wales, ambulance delay decreased 7.1% in the first quarter after Policy introduction. ED intake (triage delay) improved only in New South Wales and Queensland. Each 1% ambulance delay reduction was significantly associated with a 0.91% reduction in triage delay (p=0.014) but not ED length of stay ≤4 hours (p=0.307) or access-block/boarding (p=0.605) suggesting only partial improvement in ambulance delay overall.ConclusionThe Policy was associated with reduced ambulance delays over time in Queensland and only the immediate period in New South Wales. Associations may be due to local jurisdictional initiatives to improve ambulance performance. Strategies to alleviate ambulance delay may need to focus on the ED intake component. These should be re-examined with longer periods of post-Policy data.


1997 ◽  
Vol 31 (3) ◽  
pp. 655-669
Author(s):  
Robyn Iredale ◽  
Christine Fox

Australia's immigration policies have had a dramatic effect on school populations, especially in the state of New South Wales which receives about 40 percent of the intake. This article is based on a study that was carried out for the Bureau of Immigration, Multicultural and Population Research and the NSW Ministry of Education. The study revealed that many non-English-speaking background pupils miss out on English as a second language instruction, community languages are allowed to lapse, and aspects of the school environment, such as relations between different groups, are not given the attention that they deserve.


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