Shallow groundwater dynamics in smectite dominated clay on the Liverpool Plains of New South Wales

Soil Research ◽  
2001 ◽  
Vol 39 (2) ◽  
pp. 203 ◽  
Author(s):  
W. Timms ◽  
R. I. Acworth ◽  
D. Berhane

Dynamic shallow (<5 m) groundwater levels are an important indicator of water and salt fluxes in smectite-dominated clay on the Liverpool Plains in north-eastern New South Wales. Previous hydrogeological assessments of shallow groundwater related salinity risk have focused on regional scale distribution and interaction with rising pressure levels in confined aquifer systems. In this study, groundwater levels over a 7-year period for the saline Yarramanbah subcatchment are presented, along with data from 60 new and existing shallow piezometers and precise elevation surveying and intensive automated monitoring at selected sites. The shallow groundwater system is shown to respond to recharge; however, over the medium-term it is in hydrologic balance, with no evidence of increased water storage. A proportion of recharge is lost by discharge into deeply incised surface channels. Groundwater salinity in the banks of Warrah Creek indicate that flushing of salts from clay is related to increased flux of fresh water. Concern exists that there may be increased salt export from the catchment. If this is in fact occurring while the plains are in hydrologic equilibrium, then increased salt fluxes must be related to factors other than rising groundwater levels.

2002 ◽  
Vol 106 (1) ◽  
pp. 57-69 ◽  
Author(s):  
R.L Pressey ◽  
G.L Whish ◽  
T.W Barrett ◽  
M.E Watts

2010 ◽  
Vol 2 (5) ◽  
pp. 1378-1399 ◽  
Author(s):  
Clement E. Akumu ◽  
Sumith Pathirana ◽  
Serwan Baban ◽  
Daniel Bucher

2002 ◽  
Vol 29 (3) ◽  
pp. 313 ◽  
Author(s):  
P. C. Catling ◽  
R. J. Burt ◽  
R. I. Forrester

Statistical models are presented of the distribution and abundance of ground-dwelling mammals in eucalypt forests in relation to environmental variables within an area of approximately 24 000 km2 in north-eastern New South Wales. Environmental variables are defined as climatic or topographic variables that may be useful to map the distribution of fauna. The environmental variables examined were season, temperature, rainfall, elevation, lithology, steepness of slope, position on slope, aspect and landform profile. The probability of recording some species was higher in spring than autumn and many species were in highest abundance in areas of low temperature (high elevation). Although aspect was a significant variable in a number of models, no species was absent from any aspect category. Mid-slopes down to and including creeks and drainage lines were particularly important for many species, as were areas with flatter terrain. Although we have modelled environmental variables only there will no doubt be longer-term interactions between habitat and environmental variables. Fundamentally, environmental variables will determine the type of habitat present at a site, and the distribution of canopy communities, at least, can be predicted from environmental variables. However, other studies have shown for ground-dwelling mammals that environmental variables contribute little and it is the state of the habitat locally, and particularly the understorey, that determines their presence and abundance at a site. The results are discussed in relation to similar models using habitat variables and in relation to the use of such models in the management of ground-dwelling fauna in forests.


1982 ◽  
Vol 33 (1) ◽  
pp. 77 ◽  
Author(s):  
AH Arthington ◽  
JAL Watson

The Odonata and physicochemical properties of freshwater streams, lakes, ponds and bogs in the sand-dune systems of Fraser, Moreton and North Stradbroke Islands and Cooloola, Queensland: and Wooli, New South Wales, are described. The odonate faunas of these dune masses show some differences from those of nearby areas, and there are close associations between some species and particular types of dune fresh water. Although no physicochemical characteristics were identified that might limit these dune dragonflies to their specific habitats, the lake-dwellers in particular may be useful indicators of environmental change.


2009 ◽  
Vol 31 (2) ◽  
pp. 89 ◽  
Author(s):  
Ian F. Hayes ◽  
Ross L. Goldingay

The vast network of roads around the world has had a significant effect on wildlife and ecosystems through habitat fragmentation, reduced dispersal and mortality by collision with vehicles. Road agencies worldwide now frequently install dedicated structures to facilitate the safe crossing of roads by wildlife. We conducted surveys to determine the use of dedicated wildlife overpasses and nearby underpasses at two locations on the Pacific Highway in north-eastern New South Wales. Road-kill surveys were conducted to provide some understanding of the species commonly killed and whether the rate of road-kill was lower at one location where crossing-structures were located. Use of the crossing-structures by wildlife was monitored with sand-transects. The most frequent users were macropods, bandicoots and rodents. Macropods made greater use of overpasses (n = 104 tracks) than underpasses (n = 36), whereas underpasses were used more by bandicoots (n = 87) and rodents (n = 82) than were overpasses (n = 28, n = 15, respectively). We identified 78 road-kills of 21 species on two sections of the Pacific Highway over a 7-week period. Bandicoots (n = 16) and macropods (n = 9) were the most frequently observed victims. The mortality of wildlife was lower along the highway section with the crossing-structures (0.04 road-kills km–1) than it was along the highway section without structures (0.15 road-kills km–1). The lack of replication precludes any firm conclusion that the crossing-structures reduced road mortality but the high level of use of the crossing-structures by species that were common victims of road-kill suggests an influence.


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