http://www.researchonline.mq.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:4445 12 page(s) 2012-02-20T22:28:24.271Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:3153 Using the history of dingo-proof fences in Australia, I show that several key lessons were learnt by pastoralists, but later forgotten and had to be re-learnt. Each has application to current and future proposals to build predator-proof fences for conservation. 1. Feral predators kill and eat native fauna. 2. Predators go under or through fences, or climb fences. 3. Predator-proof fences must be maintained. 4. Maintenance is expensive and must be continued indefinitely. 5. Scalp bonuses do not control predators and are a waste of money. Despite some assertions from conservationists, there is no evidence that the motive for building a fence (conservation versus growing sheep) is any guarantee of better performance. Proponents of predator-proof fences (and funding agencies) need to ask two key questions. 1. What is the real objective of the fence, and how do we measure its success? 2. What happens if/when the fences are successful? Unless predators are controlled outside the fence, then the enclosure remains a captive breeding zoo which achieves little for conservation at a landscape-scale. 2012-02-16T04:20:56.614Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:379 The degree to which Southern Hemisphere climatic changes during the end of the last glacial period and early Holocene (30-8 ka) were influenced or initiated by events occurring in the high latitudes of the Northern Hemisphere is a complex issue. There is conflicting evidence for the degree of hemispheric teleconnection and an unresolved debate as to the principle forcing mechanism(s). The available hypotheses are difficult to test robustly, however, because the few detailed palaeoclimatic records in the Southern Hemisphere are widely dispersed and lack duplication. Here we present climatic and environmental reconstructions from across Australia, a key region of the Southern Hemisphere because of the range of environments it covers and the potentially important role regional atmospheric and oceanic controls play in global climate change. We identify a general scheme of events for the end of the last glacial period and early Holocene but a detailed reconstruction proved problematic. Significant progress in climate quantification and geochronological control is now urgently required to robustly investigate change through this period. 2012-01-05T04:45:58.211Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:3366 Fences are neglected heritage components of railway corridors. They record the development of colonial railways, they often contain components typical of earlier technology, they are usually considerably more robust than farm fences of similar age, and finally, they can provide accurate records of environmental changes in the adjoining landscapes. Four examples show the rich range of heritage information in railway fences. Massive fences built by the South Australian Railways in the late 19th century reflected British technology and practice, quite at odds with local farming practice. Droppers patented by Arthur Gatenby in Tasmania in 1888 were widely adopted by farmers and railways in various states, and are the most widespread and abundant dropper in railway fences. In a vain attempt to stop the eastward advance of rabbits, the New South Wales government built 655km of rabbit-proof fence across the state in the 1880s, primarily by hanging netting on existing railway fences. Buried railway fences in northern South Australia record the history of failed northern expansion of cultivation beyond Goyder's Line in the 1870s. Finally, the almost insuperable problems of conserving these fences are addressed, concluding that detailed recording is perhaps the only feasible approach. 2012-01-05T03:43:40.067Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:6050 The body of literature investigating the causes of vector borne disease (VBD) outbreaks (such as Ross River virus) in coastal subtropical regions of Australia, stresses that the relationship between VBD and the biophysical environment, including climate variability and change, is not simple. This paper provides an integrated exploration of VBD incidence in the context of socio-biophysical interactions (such as population dynamics, human settlement growth and biophysical change). The study focuses specifically on the coastal subtropical regions of southeast Queensland and northeast New South Wales. These regions (i) possess the natural landscapes that are conducive to mosquito habitats, (ii) are exposed to climatic conditions favourable to VBD such as Ross River virus, and (iii) are experiencing rapid and continuing population growth, significant urban development, and consequential environmental modification. Together, the emerging socio-biophysical circumstances raise questions as to the future risks of VBD incidence in the region. Options for mitigative and adaptive planning tools and strategies for the sustainable management of such diseases in urban subtropical coastal zones are discussed. 2011-06-29T01:59:39.137Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:12800 2 page(s) 2011-05-25T22:00:35.570Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:12316 Wildfires can induce or enhance soil water repellency under a range of vegetation communities. According to mainly USA-based laboratory studies, repellency is eliminated at a maximum soil temperature (T) of 280–400°C. Knowledge of T reached during a wildfire is important in evaluating post-fire soil physical properties, fertility and seedbed status. T is, however, notoriously difficult to ascertain retrospectively and often based on indicative observations with a large potential error. Soils under fire-prone Australian eucalypt forests tend to be water repellent when dry or moderately moist even if long unburnt. This study aims to quantify the temperature of water repellency destruction for Australian topsoil material sampled under three sites with contrasting eucalypt cover (Eucalyptus sieberi, E. ovata and E. baxteri). Soil water repellency was present prior to heating in all samples, increased during heating, but was abruptly eliminated at a specific T between 260 and 340°C. Elimination temperature varied somewhat between samples, but was found to be dependent on heating duration, with longest duration resulting in lowest elimination temperature. Results suggest that post-fire water repellency may be used as an aid in hindcasting soil temperature reached during the passage of a fire within repellency-prone environments. 2011-03-24T13:20:08.640Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:11997 The results of a pilot study to assess the risk from tsunamis for the Seaside-Gearhart, Oregon region will be presented. To determine the risk from tsunamis, it is first necessary to establish the hazard or probability that a tsunami of a particular magnitude will occur within a certain period of time. Tsunami inundation maps that provide 100-year and 500-year probabilistic tsunami wave height contours for the Seaside-Gearhart, Oregon, region were developed as part of an interagency Tsunami Pilot Study(1). These maps provided the probability of the tsunami hazard. The next step in determining risk is to determine the vulnerability or degree of loss resulting from the occurrence of tsunamis due to exposure and fragility. The tsunami vulnerability assessment methodology used in this study was developed by M. Papathoma and others(2). This model incorporates multiple factors (e.g. parameters related to the natural and built environments and socio-demographics) that contribute to tsunami vulnerability. Data provided with FEMA's HAZUS loss estimation software and Clatsop County, Oregon, tax assessment data were used as input to the model. The results, presented within a geographic information system, reveal the percentage of buildings in need of reinforcement and the population density in different inundation depth zones. These results can be used for tsunami mitigation, local planning, and for determining post-tsunami disaster response by emergency services. (1)Tsunami Pilot Study Working Group, Seaside, Oregon Tsunami Pilot Study--Modernization of FEMA Flood Hazard Maps, Joint NOAA/USGS/FEMA Special Report, U.S. National Oceanic and Atmospheric Administration, U.S. Geological Survey, U.S. Federal Emergency Management Agency, 2006, Final Draft. (2)Papathoma, M., D. Dominey-Howes, D.,Y. Zong, D. Smith, Assessing Tsunami Vulnerability, an example from Herakleio, Crete, Natural Hazards and Earth System Sciences, Vol. 3, 2003, p. 377-389. 2011-03-01T04:30:56.654Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:12005 1 page(s) 2011-03-01T04:30:26.705Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:11979 4 page(s) 2011-02-28T14:20:11.804Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:11964 It is commonly assumed that northwest aspects are driest and most prone to bushfires and that steeper slopes bring higher fire risks. This study examined bushfires in the Sydney region to determine whether northwest slopes are more prone to fire and whether they experience more severe burning, and to analyse the relationship between slope and burn severity. Bushfire data were obtained from multiple sources. Remotely sensed imagery was used to derive fire severity using ‘before’ and ‘after’ NDVI data and a difference method using TM5/TM4 ratios. Severity classes were created using an ISODATA classification to correspond to: no burn, and low, medium, high and extreme intensity. Aspect and slope data were derived from DTM datasets at 25-metre resolution. Aspect was grouped into eight classes and a “northwest score” calculated using a sinusoidal function. The aspect classes associated with unburnt and low to extreme burn severity were compared using a Chi-squared test. An ANOVA analysis was used to test the trends in mean slope values associated with low to extreme fire severity. Relationships between environmental data are influenced by resolution and 25-metre resolution may introduce variations that are smaller than a fire’s operational scale, therefore analyses were repeated with different levels of aggregation. The study found statistically significant differences between the aspect of fire affected areas and those of the fire environs, but no aspect was preferred in all fires. The influence of aspect on severity was not simple: southerly aspects were associated with low intensity fires, high intensity fires were associated with northwest aspects, and extreme intensity burning was found on all aspects. There was a strong inverse relationship between slope and burn severity for all fires. The aggregated data did not reveal new or altered relationships; generally these analyses strengthened the statistical significance of findings with un-aggregated data. 2011-02-28T00:50:31.769Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:11334 Forest fires tend to cause accelerated soil erosion with some of the redistributed sediment entering the fluvial system. Where there is a reservoir downstream, enhanced sediment accumulation will tend to take place on its floor. This paper concerns the application of different techniques to sediment cores obtained from the floor of Lake Burragorang, the main water supply reservoir for Sydney and explores the possibility not only of discriminating between sediment from burnt and unburnt sources but also between sediment derived from areas subject to different fire severities. Two main soil properties have been investigated: mineral magnetism and thermal activation characteristics (TAC). Laboratory heating experiments have been conducted on long unburnt material (>30 years) to ascertain temperature thresholds at which changes to the soil characteristics occur. Owing to the dominance of the mineral magnetite in soils from the study area, only high severity fires can be detected using mineral magnetic analysis due to the high temperature at which magnetite properties transform (577 °C). Lower temperature thresholds have been explored by TAC analysis. Using this technique it is possible to detect whether temperatures in excess of 110 °C have been reached. These experiments have shown that individual soil grains have retained a ‘memory’ effect of previous fire events, so that it has been necessary to find sources of material not previously exposed to fire (unexposed bedrock) to test the validity of the assumptions of the technique. The influence of the well-documented fire history has been explored in different parts of the Lake Burragorang catchment using mineral magnetic analysis and reference to SCA records of burn events within the catchment since 1960. This has enabled assessment of the influence of (i) different landscape units, (ii) the number of fires, and (iii) the time since the last fire on various magnetic signatures derived from within the catchment, which could possibly be used to build a picture of the sources of sediment within the catchment deposited on the lake floor. The potential and limitations of applying these techniques to sediment stacks for the purpose of reconstructing fire history, severity and frequency are discussed. 2011-01-17T05:00:24.600Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:11335 Cosmogenic radionuclides are commonly used to determine local surface lowering rates e.g., erosion rates of outcrops, and can be used to infer soil production rates by sampling saprolite and using the saprolite lowering rate as the conversion rate of saprolite to soil (Wilkinson and Humphreys, 2005). Among the various cosmic ray scaling considerations, inferring soil production rates requires an account of saprolite shielding by soil, and situations where time-invariable soil depth applies are commonly sought. However, invariable local soil depth over tens of thousands of years is unrealistic at many sites, especially where the last glacial period may have been accompanied by different rates of erosion than those observed today. Testing the constant soil depth assumption has been accomplished in two ways: morphometric analysis and slope process modelling (Heimsath et al., 1997; Heimsath et al., 2000) and, the emergence of tors from the surrounding soil (Heimsath et al., 2001). A further method involves measuring erosion rates from various parts of the catchment. For instance, in the Blue Mountains (33°S and ~ 1000 m. a.s.l. in the southeastern highlands of Australia), the erosion rate of a small catchment, determined from the 10Be concentration of stream sediment, is greater than all soil production rates from within that catchment. This casts doubt on the veracity of the apparent soil production rates since calculations of catchment erosion rates are not dependent upon a constant soil depth assumption. Apparent soil production rates may be artificially low if the modern soil depth, used in surface lowering calculations, was thinner for the bulk of the 10Be accumulation time. Considering the site was above the treeline during the LGP (Hesse et al., 2003), soil production rates are recalculated using a soil cover 30 cm thinner than that observed; this revision corresponds with the absence (and probable erosion) of saprolite below soils less than ~ 30 cm deep, and the presence of saprolite under deeper soil. Revised soil production rates overlap the catchment average; furthermore, the revised soil production function (plot of soil production rate v. soil depth) accords with models from the literature. This TCN data set adds to mounting evidence that the Blue Mountains were dramatically affected by the last glacial period. Not only was aeolian transport and sand dune formation active, but generally, soils were probably ~ 30 cm thinner on plateaux surfaces, and ~ 10% of surfaces likely experienced total soil and saprolite erosion. These phenomena were probably a result of sparse, treeless vegetation (Hesse et al., 2003) which contrasts with heath and forest that currently covers the entire plateau surface. 2011-01-17T05:00:21.658Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:11337 Mineral Magnetism (MM) and Thermal Activation Characteristics (TAC) are two soil or sediment properties that become enhanced when specific temperature thresholds are reached. Both have the potential to facilitate reconstruction of past fire events and their severity. The temperature thresholds required for changes to magnetic minerals are determined by the Curie Point(s) (CP) of dominant minerals within a sample. During a fire, when soil temperature (T) exceeds the CP, ferromagnetic minerals are formed, creating a chemical remanent magnetisation (CRM), which is retained by the heated grains. Changes to common minerals within the soil occur at T between 220-270 °C (Lepidocrocite) or around T > 570 °C (magnetite). Lower temperature thresholds have been investigated for changes in thermoluminesece (TL) sensitivities of quartz grains, which increase following heating. Measurement of TAC is conducted by monitoring an electron trap at around 110 °C, where TL sensitivity (light output of quartz grains) experiences a peak after application of a small dose of beta radiation when the sample is subsequently heated. In this study, we examine the changes in MM and TAC under controlled laboratory conditions for a series of temperatures and heating durations on a quartz-rich soil material from NSW, Australia that has not been affected by wildfire for > 30 years. The MM results identified that the soil assemblage was retaining a fire-enhanced signature from previous fire events of temperatures > 400 °C. This was established by measuring MM susceptibility changes during heating and cooling cycles. Results from the TAC experiments on the same sample confirmed the retention of a fire-enhanced signal. Variability of the thermal histories of the sample was conducted by comparison of TAC results from multi-grained aliquots (500 grains) with single grains. Preliminary results suggested that different grains within the sample had been heated to temperatures ranging between 400 - 800 °C. The findings from this work highlight potential problems when using MM or TAC to detect recently burnt material, due to the retention of fire-enhanced signal. However, this work has also highlighted the opportunity for using temperature thresholds of both MM and TAC to potentially enable the reconstruction of variations in fire severity over geological time. 2011-01-17T05:00:18.823Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:11336 The spectacular incised valleys of the Blue Mountains Plateau in the west and south-west of the Permo-Triassic Sydney Basin are the focus of this paper. The evolution of these valleys has been shown to be controlled by knickpoint retreat following uplift along the Lapstone Structural Complex. However, very little investigation has been conducted into the processes which dominate after the knickpoint has past, in particular those processes which facilitate valley widening. Investigations in the incised Nattai River valley, a tributary of the Wollondilly River in the south-west of the Basin, found hillslopes which are characterized by mass movement, particularly rock fall, debris flows, rotational slumping and large landslides. To determine the relative importance of mass movement in denudation, we compared modern rates of sediment yield from hillslope plots and suspended load in the Nattai catchment with long term rates of sediment yield and denudation calculated from incision below Tertiary basalts, cosmogenics and apatite fission track ages determined for the Blue Mountains Plateau. The comparison revealed that the average modern background denudation rate is an order of magnitude less than the long term average, which implies a very low sediment yield for the majority of the time and compares well with field observations. The background rates are episodically punctuated by short term sediment yield events which are at least an order of magnitude higher than the long term average and higher than erosion rates measured following the 2001/02 bushfires. We suggest that following knickpoint retreat, the primary process of denudation in the Nattai valley is extreme erosion events on hillslopes which facilitates valley side-wall retreat. Sediment generated through mass movement directly enters the stream network or is stored on the lower slopes and valley floor to be progressively reworked by floods capable of remobilizing sand to boulder sized material. The mass movement events appear to be linked to lithology which suggests that mass movement and side-wall retreat is an important geomorphic process in the evolution of the incised valleys of the Blue Mountains Plateau. 2011-01-17T03:40:06.027Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2042 A sudden reduction in rainfall occurred in the southwest of Western Australia in the mid-20th century. This reduced inflows to the Perth water supply by about 120 GL (42%) and led to an acceleration of projects to develop new water sources at a cost of about $300 million. The reduction in rainfall was coincident with warmer temperatures. A major analysis of these changes indicated that the changes in temperature were likely caused by the enhanced greenhouse effect and that the changes in rainfall were likely caused by a large-scale reorganization of the atmospheric circulation. We explore an alternative hypothesis that large-scale land cover change explains the observed changes in rainfall and temperature. We use three high-resolution mesoscale model configurations forced at the boundaries to simulate (for each model) five July climates for each of natural and current land cover. We find that land cover change explains up to 50% of the observed warming. Following land cover change, we also find, in every simulation, a reduction in rainfall over southwest Western Australia and an increase in rainfall inland that matches the observations well. We show that the reduced surface roughness following land cover change largely explains the simulated changes in rainfall by increasing moisture divergence over southwest Western Australia and increasing moisture convergence inland. Increased horizontal wind magnitudes and suppressed vertical velocities over southwest Western Australia reduce the likelihood of precipitation. Inland, moisture convergence and increased vertical velocities lead to an increase in rainfall. Our results indicate that rainfall over southwest Western Australia may be returned to the long-term average through large-scale reforestation, a policy option within the control of local government. Such a program would also provide a century-scale carbon sink to ameliorate Australia's very high per capita greenhouse gas emissions. 2011-01-13T05:10:30.492Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:3766 With the exception of the diatoms, little is known of the extinction, colonization, and succession of marine floras during glacial cycles. Here we study both morphological and biochemical fossils in two sediment cores from the Antarctic to unravel the sequence of events over a single glacial cycle. The cores, from the nearshore continental shelf off the Windmill Islands (66°S, 110°E), east Antarctica, span the period from Marine Isotope Stage 3 or earlier to the present. New high-performance liquid chromatography and mass spectrometry methods were used to study fossil pigments with additional data from siliceous microfossils, lithological analyses, and radiocarbon dates. Results show two response processes. First, there is the large-scale impact of the expanding ice sheet in removing the flora from the inner shelf, primarily through the denial of light, destabilization of the substratum, and elimination of habitats. Second, there are a number of glacial climate interactions that have a surprisingly strong influence on recolonization and succession. These include sea ice extent and the proximity of the ice edge, the annual duration of open water, the stabilization of the substratum first by benthic diatoms and later by macrophyte algae, and relative sea level. A period of warmer climate in the mid-Holocene had a considerable influence on the composition and species diversity of the marine flora. These are the first data on the timing of colonization and succession of marine floras over a glacial cycle based on both morphological and biochemical fossils. 2011-01-11T09:53:34.348Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:11218 Optical dating of linear sand dunes in the Simpson Desert has recently confirmed the great depth (> half dune height) of sand mobilised in the Holocene in some dunes. These data, and the observation today of locally mobile dunes, contradict the long-held belief that the Australian desert has been inactive since the end of the last glacial interval and force us to reassess how these dunes have became mobile in part, or at times, during the Holocene. Several sites in the Simpson and Strzelecki Desert dune fields were examined to determine the local effect of vegetation on sand mobility on the dune surfaces. The vegetation structure comprises both perennial bushes and ephemeral herbs and forbs which contribute protective cover while growing after rains and for some time after while dead. Cyano-bacterial crusts further enhance the surface area with some protective cover. The responsiveness of the vegetation to drought may see cover vary from >60% to <20% over a drought cycle. As expected there is a positive relationship between sand mobility and the proportion of unvegetated dune surface. There is no strict threshold of sand movement at high cover levels but the exponential relationship between bare area and volume of mobile sand sees effective total mobility at about 50% cover. At this level there is also a morphological shift from hummocky dune surfaces to mobile dunes with avalanche faces. These two states represent contrasting morphodynamic relationships: at high levels of cover the fluctuation of cover with climate variability (especially rainfall modulated by ENSO and PDO) determines the amount of sand transport while at low levels of cover sand transport is free of the influence of vegetation at all times. Extreme, prolonged and rare drought may be required to remove perennial vegetation from dune crests showing this level of activity. Despite these findings, mobile dunes are comparatively rare in Australia today. Most appear to be in areas of localised vegetation disturbance (from grazing, roads etc.) but there is low net lateral transport (it is ‘back-and-forth’). The few dated dunes also suggest spatially and temporally variable activity in the Holocene with low volumes of mobile sand. The supply of erodible sand on the dunes themselves is thought to combine with seasonally opposed winds to minimize net sand transport. 2011-01-11T08:41:13.401Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:11219 1 page(s) 2011-01-11T08:41:08.770Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:11220 Vegetation plays a key role in the stabilisation of sand dunes in the Strzelecki Desert and fluctuations in cover create opportunities for erosion to occur. Through the use of an Advanced Very High Resolution Radiometer (AVHRR) time series of Normalised Difference Vegetation Index (NDVI), from 1992-2004, a link has been found between large rainfall deviations from the mean and fluctuations in NDVI. The rapid response in NDVI occurs due to the flourish of ephemeral vegetation and the greening up of existing perennial vegetation present in the Strzelecki Desert. Higher resolution Landsat TM data was used for comparison with ground measurements of vegetation cover. Through vegetation surveys taken across longitudinal sand dunes a good correlation has been formed between perennial vegetation cover and Landsat TM derived NDVI. The field sites used cover a wide extent of the north eastern Strzelecki Desert. Horizontal and Vertical wind profiles, constructed using two arrays of three cup anemometers set up perpendicular to longitudinal sand dunes, have revealed that log-linear profiles are not apparent due to the acceleration of wind up windward slopes of sand dunes in the Strzelecki Desert. The amount of acceleration is determined by the presence of perennial vegetation cover on the upper and lower flanks of the dunes. Dunes found with a perennial cover of greater than 40-50% displayed deceleration close to the ground, up the windward slope, resulting in surface protection. Dunes with less vegetation than this showed acceleration. This all combines to reaffirm the notion that vegetation plays an important role in the stabilisation of desert sand dunes due to the decrease in wind speed and therefore an increase in the threshold for sand movement. 2011-01-11T08:41:08.394Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:11038 Fences are ubiquitous in most western societies and have a history spanning several millennia. Many are important historic heritage, recording changes in technology and attempts to settle and manage land. Various forms of log, brush and post-and-rail fences occur widely in south-eastern Australia. Although common in the 19th and early 20th centuries, most have been replaced by post-and-wire on farmlands. However, those that have survived, usually in forests, are now rare, are highly significant historic heritage, and are at severe risk from recurrent wildfires. Three examples illustrate the problems: chock-and-log fence (western NSW), cockatoo fence (south-eastern NSW), and log fences (central highlands of Tasmania). They are all likely to be more than 100 years old and are currently among the only known examples to survive. There is no realistic way to protect the fences from either wildfire or hazard-reduction burning. Ageing and rot predispose the logs to ignition by smouldering embers, and normal fire containment procedures make little allowance for historic heritage. The only approach is to record the fences before they go up in smoke. As fences are distributed world-wide, the problem is not restricted to Australia, and probably has not been recognised in other countries. 2010-12-22T05:30:08.598Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:10794 8 page(s) 2010-11-29T07:20:22.409Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:10760 Recent work in the water supply catchments of Sydney, Australia, has explored the potential for using a range of sediment tracing approaches in post-fire landscapes. Sediment tracing techniques offer the potential to elucidate sources and pathways of sediment which can assist with mitigation and remediation of post-fire erosion events. Furthermore, their preservation in downstream sedimentary sequences can provide important information on recent fire frequency and erosional response. Whilst the theory behind tracing approaches is relatively straightforward, complications can arise in their application, especially in post-fire landscapes where impacts tend to be heterogeneous. In this contribution we appraise mineral magnetic and geochemical techniques for discriminating sediment sources and delivery dynamics, identify strengths and limitations of each approach and problems encountered in their application. In level terrain, clear responses were seen in measured tracing parameters with respect to fire severity. For example, low-frequency magnetic susceptibility values (Xlf ) of sediment sourced from burnt areas (c. 8.0 10⁻⁶ m³ kg⁻¹) were an order of magnitude greater than those of sediment derived from long-unburnt areas (c. 0.8 10⁻⁶ m³ kg⁻¹) in response to transformation of amorphous Fe-minerals at high temperature. Similarly, severely burnt soil showed enrichment in nutrient and trace element properties relative to moderate and unburnt soil, most likely in association with mineralization of organic matter. For example, PbO concentrations increase from c.30 mg kg⁻¹ in unburnt soil to c. 80 mg kg⁻¹ in severely burnt soil. However, signatures are less clearly defined in slope-derived soil samples, specifically footslope areas where material burnt and mobilised in previous wildfire events has accumulated. Ambiguous signatures from these zones will increase uncertainty in the output of sediment unmixing models. The role of footslope storage zones can be quantified through construction of fallout radioisotope-based sediment budgets which permit exclusion of ambiguous storage zones from unmixing models. We conclude that fire-related sediment source data must be interpreted in the context of slope or catchment scale sediment budgets. 2010-11-26T12:40:29.217Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:10762 Old soils on ancient landscapes in a dry and fire-prone continent is how Australia is portrayed by its citizens and by others across the globe. This message, initially developed by various researchers, has entered the public domain by a variety of pathways but especially by books and articles in popular journals and magazines. Mary White’s After the Greening: the Browning of Australia and Tim Flannery’s The Future Eaters are prime examples. But how old are its landscapes and soils, and how might this be tested? Recent work using terrestrial cosmogenic nuclides and OSL dating provide valuable insights on this since they allow dating of exposed rock and mantled rock providing that a suitable soil production function can be determined (Wilkinson and Humphreys 2005). These methods display similar results to denudation rates established by other means (e.g. river loads, hillslope processes, catchment averages etc). In SE Australia, denudation rates are mostly between 5-50 m/Ma and these results are similar to those from other regions, across a variety of lithologies including basalt, granite, sandstone, and limestone. On this basis a 1 m mantle, a typical maximal thickness in upland SE Australia, is formed (renewed) in 20–200 ka. In drier parts of Australia denudation rates decline to 1–2 m/Ma. Even at these rates and when considered over long periods of time a landscape might expect at least c. 600 m of lowering since the beginning of the Palaeozoic. Truly ancient landscape remnants, if they exist, will be rare. Equally, truly ancient soils that preserve their essential quality despite residing at the surface of a landscape for long periods will be very special indeed. 2010-11-26T12:40:28.042Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:10623 8 page(s) 2010-11-17T04:30:06.819Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:378 Longitudinal (linear) sand dunes of the Simpson and Strzelecki dunefields in eastern central Australia present a paradox. Low levels of activity today stand in contrast to luminescence dating which has repeatedly shown deep deposits of sand on dune crests dating to within the late Holocene. In order to investigate the nature of dune activity in the Simpson–Strzelecki dunefield, vegetation and sand mobility were investigated by detailed vegetation survey and measurement of rippled area and loose sand depth of dunes at three sites along a climatic gradient. The response of both vegetation and sand movement to inter-annual climate variability was examined by repeat surveys of two sites in drought and non-drought conditions. Projected plant cover and plant + crust cover were found to have inverse linear relationships with rippled area and the area of deep loose sand. No relationship was found between these measures of sand movement and the plant frontal area index. A negative exponential relationship between equivalent mobile sand depth on dune surfaces and both vascular plant cover and vascular + crust cover was also found. There is no simple threshold of vegetation cover below which sand transport begins. Dunes with low perennial plant cover may form small dunes with slip faces leading to a positive feedback inhibiting ephemeral plant growth in wet years and accelerating sand transport rates. The linear dunefields are largely within the zone in which plant cover is sufficient to enforce low sand transport rates, and in which there is a strong response of vegetation and sand transport to inter-annual variation in rainfall. Both ephemeral plants (mostly forbs) and crust were found to respond rapidly to large (> 20 mm/month) rainfall events. On millennial time-scales, the level of dune activity is controlled by vegetation cover and probably not by fluctuations of wind strength. Land use or extreme, decadal time-scale, drought may destabilise dunes by removing perennial plant cover, accelerating wind erosion. 2010-10-26T07:57:37.604Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:950 The Australian continent is characterised by an extremely variable surficial geochemistry, reflecting the varied lithology of Australian basement rocks. Samples representative of Australian aeolian dust have been collected in (1) regions where meteorological records, satellite observation and wind erosion modelling systems have indicated frequent dust activity today (mainly the Lake Eyre Basin), and (2) from deposits of mixed dust materials. The ⁸⁷Sr/⁸⁶Sr and ¹⁴³Nd/¹⁴⁴Nd isotopic composition of the fine (< 5 μm) fraction of Australian dust samples was measured for comparison with the Sr and Nd isotopic composition of fine aeolian dust that reached the interior of the East Antarctic Plateau. The isotopic field for Australian dust is characterised by ⁸⁷Sr/⁸⁶Sr ratios ranging from 0.709 to 0.732 and ε_Nd(0) between − 3 and − 15. The low Sr radiogenic values and ε_Nd(0) of − 3 obtained for Lake Eyre samples are explained by the lithology of the Lake Eyre catchment showing a dominance of Tertiary intraplate volcanic material. These new data show that the dust contribution from Australia could have been dominant during interglacial periods (Holocene and Marine Isotopic Stage 5.5) to Antarctica. During glacial times, studies have shown that the South American dust isotopic signature overlaps the glacial Antarctic dust field suggesting this region as dominant aeolian dust source. However, the Australian Lake Eyre dust isotopic signature partially overlaps with the Antarctic glacial dust signature. We propose that the relatively greater contribution of Australian dust inferred for Antarctic interglacial ice compared with glacial ice is not directly reflective of changes in dust transport pathway, but instead is related to a differential weakening of the South American sources during interglacial time with respect to the Australia sources. Our findings have implications for interglacial versus glacial atmospheric circulation, at least in the Southern Hemisphere. 2010-10-26T07:56:43.214Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:748 On upland Triassic sandstone slopes of the western Blue Mountains, nonswamp, sclerophyllous heath (shrub-dominated vegetation) on shallow soils is commonly found downslope and adjacent to sclerophyllous forest on deeper soils. Some consider heath—and thus shallow soils—as favouring west-facing slopes, which are expected to experience drier microclimates due to insolation, strong and desiccating winds, and severe summer fires. However, our analysis of extensive areas with heath on shallow soils, based on vegetation and topographic maps, and fieldwork of uplands with various degrees of dissection, suggests that aspect is a poor predictor of shallow soils. Rather, shallow soils and heath are found on short slopes and the lower segments of longer slopes with the latter significantly steeper than forested segments. The shallow–deep soil boundary, marked by contrasting modern vegetation structures, does not signify a catchment area threshold, and correspondingly, the vegetation patterns are not in balance with distributary catchment processes, as short slopes are mantled exclusively by shallow soils. Instead, the soil depth boundary represents the propagation of base-level lowering signals, which takes place not only by the headward retreat of knickpoints but also via increased lowering of slope segments adjacent to drainage lines. This leads to steep slopes immediately adjacent to canyons, narrow gorges, and small steep valleys, that are mantled by shallow, discontinuous soils undergoing rapid erosion. These steep slopes persist in the landscape for ≥ 10 My after upland stream rejuvenation until incision of more weatherable Permian sediments, underlying the Triassic cliff-forming sandstones, triggers rapid lateral expansion of gorges. Once shallowly mantled and steeper slopes adjacent to streams are consumed by gorge widening, slopes adjacent to wide gorge clifflines reflect former upland drainage patterns rather than the redirected flow to rapidly widening gorges. Hence, modern vegetation patterns reflect a significant phase of landform development, perhaps combined with enhanced erosion during the Last Glacial Period that is compounded by a humped soil production function on bedrock. 2010-10-26T07:55:41.645Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1424 13 page(s) 2010-10-26T07:54:34.802Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:384 Aridity in Australia has generally been associated with glacial intervals of the last few glacial cycles. The causes and nature of aridity varied from north to south over the continent. In northern and central Australia, reduced monsoon rain in global cold stages caused lakes and rivers to dry, vegetation to become more sparse, sand dunes to become active, and dust advection to increase. While the monsoon is correlated with warmer global temperatures and high sea levels overall, the exact timing of the greatest development of the monsoon in Stage 5 remains uncertain. In southeastern Australia, the proxy records give a less clear picture. While vegetation seems to have been more sparse in cold stages and sand dune activity and dust flux consequently greater, records of runoff in rivers and lakes have mixed or opposite behaviour to northern or central Australia. The nature of aridity in southeastern Australia is not analogous to conditions anywhere on the continent today. Greatly reduced temperatures over the central and southern interior, greater influence of snow and periglaciation on runoff, high groundwater tables, lower rainfall and reduced atmospheric carbon dioxide levels may all have contributed to and interacted to produce the reconstructed picture of a cold, sparsely vegetated arid landscape with large rivers and perennial lakes. The largest changes in circulation patterns over the glacial cycle probably occurred in the location and/or intensity of summer tropical convergence in northern Australia. Over southern Australia, changes to the temperature and humidity of the westerly circulation have been more significant than the small fluctuations in latitude of the sub-tropical high pressure ridge. 2010-10-26T07:49:54.430Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2300 Santorini, Greece is a major explosive volcano. The Santorini volcanic complex is composed of two active volcanoes—Nea Kameni and Mt. Columbo. Holocene eruptions have generated a variety of processes and deposits and eruption mechanisms pose significant hazards of various types. It has been recognized that, for major European volcanoes, few studies have focused on the social aspects of volcanic activity and little work has been conducted on public perceptions of hazard, risk and vulnerability. Such assessments are an important element of establishing public education programmes and developing volcano disaster management plans. We investigate perceptions of volcanic hazards on Santorini. We find that most residents know that Nea Kameni is active, but only 60% know that Mt. Columbo is active. Forty percent of residents fear that negative impacts on tourism will have the greatest effect on their community. In the event of an eruption, 43% of residents would try to evacuate the island by plane/ferry. Residents aged >50 have retained a memory of the effects of the last eruption at the island, whereas younger residents have no such knowledge. We find that dignitaries and municipal officers (those responsible for planning and managing disaster response) are informed about the history, hazards and effects of the volcanoes. However, there is no “emergency plan” for the island and there is confusion between various departments (Civil Defense, Fire, Police, etc.) about the emergency decision-making process. The resident population of Santorini is at high risk from the hazards associated with a future eruption. 2010-10-26T07:48:39.061Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2301 The paroxysmal eruption of Santorini (ca. 3500 BP), referred to as the Late Bronze Age (LBA) eruption, probably generated multiple tsunami; their occurrence and impacts being cited frequently in scientific papers and articles. This paper examines what is known about any LBA tsunami, noting possible mechanisms of generation and identifying sedimentological traces. Firstly, the eruption sequence is outlined providing the context in which tsunami genesis may have occurred. Secondly, the arguments forwarded for the tsunami and a summary of the evidence is given. Thirdly, results of a new geological investigation for LBA tsunami deposits at 41 coastal sites from Crete and Kos are presented. The data are used to test the hypothesis that the LBA eruption generated an east Mediterranean-wide tsunami. It will be seen that no terrestrial geological evidence is identified. The paper re-examines the original arguments presented for LBA tsunami, challenging them because their founding assumptions are flawed. Together, the new data and the re-analysis of the original tsunami hypothesis indicate that there is insufficient evidence to demonstrate that any significant far-field tsunami propagated throughout the entire east Mediterranean as frequently purported. Some terrestrial evidence exists to suggest localised near-field tsunami inundation. There is good submarine evidence however, to suggest that a tsunami was focused to the W and WSW. The results have important implications for understanding the volcano-related tsunami hazard within the region and elsewhere. 2010-09-30T06:14:34.129Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:317 Dust raising and transport are common and important processes in Australia today. The aridity of the Australian continent and high climatic variability result in widespread dust raising in the arid and semi-arid areas and transport to the humid margins and surrounding oceans. The supply of erodible particles appears to be the greatest limitation on total flux of transported dust. Dust raising is greatest in the Lake Eyre Basin, including the Simpson Desert, and Murray-Darling Basin where internal drainage renews supplies of fine particles to the arid zone. In the west and northwest dust entrainment is low, despite considerable aridity. The marine record of dust flux shows at least a threefold increase in dust flux, compared with the Holocene, in the last glacial maximum in both tropical and temperate Australia, driven by weakened Australian monsoon rains and drier westerly circulation, respectively. Despite the widespread confirmation of aeolian dust deposits in southeastern and southwestern Australia, dated or quantified records are extremely rare. The dominant model of Australian dust deposits, the clay-rich ‘parna’, is shown to be poorly substantiated while modern and ancient dust deposits examined in detail are shown to bear a strong similarity to conventional definitions of loess. 2010-09-30T06:13:24.746Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2134 Optically stimulated luminescence dating of glaciofluvial and glacial-lake shoreline sediments indicates that the Bunger Hills area, in coastal East Antarctica, was largely ice free by the Last Glacial Maximum (LGM). Deglaciation commenced as early as 30 ka, and the southern hills were completely exposed by 20 ka. The sediments do not record evidence of an LGM readvance. Previous reconstructions of LGM ice limits for the area are incompatible with this new evidence. 2010-09-30T06:11:09.953Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2141 In many catchments in southeastern Australia, alluvial stores have been the dominant source of sediments mobilised in the period since European settlement. In Bega catchment, on the South Coast of New South Wales (NSW), this has been reflected by dramatic changes to river morphology. Extensive volumes of material have been released and efficiently flushed to the lowland plain, with a sediment delivery ratio of almost 70%. However, only 16% of these alluvial sediments have been flushed through to the estuary, as antecedent controls on valley width have resulted in the lowland plain acting as a large sediment sink. The changing nature of sediment source, transfer and accumulation zones has varied markedly from subcatchment to subcatchment. The volume of material supplied to the lowland plain from differing subcatchments is not related to subcatchment area. Rather, the pattern of river types dictates the spatial variability in storage and transfer. Over 67% of sediment released has been sourced from just 25% of the catchment, from subcatchments characterised by large valley fills (cut and fill River Style) that previously stored extensive volumes of material at the base of the escarpment. These parts of Bega catchment were especially sensitive to disturbance. Sediment exhaustion from these parts of the catchment, and from river courses elsewhere, has major implications for the geomorphic recovery potential of rivers, constraining what can be realistically achieved in terms of river rehabilitation. 2010-09-30T06:09:49.817Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2140 1. Methods to assess the physical habitat available to aquatic organisms provide important tools for many aspects of river management, including river health monitoring, determination of river restoration/rehabilitation strategies, setting and evaluating environmental flows and as surrogates for biodiversity assessment. 2. Procedures used to assess physical habitat need to be ecologically and geomorphologically meaningful, as well as practicable. A conceptual methodological procedure is presented that evaluates and links instream habitat and geomorphology. 3. The heterogeneity of habitat potential is determined within geomorphic units (such as pools, runs, riffles) by assessing flow hydraulics and substrate character. These two variables are integrated as hydraulic units - patches of uniform flow and substrate. 4. This methodology forms a logical extension of the River Styles framework that characterizes river form and behaviour at four inter-related scales: catchments, landscape units, River Styles (reaches) and geomorphic units. As geomorphic units constitute the basis to assess aquatic habitat availability, and they form the building blocks of river and floodplain systems, intact reaches of a particular River Style should have similar assemblages of instream and floodplain habitat. 5. An application of the hydraulic unit procedure is demonstrated in gorge, partly-confined and alluvial River Styles from the Manning catchment in northern New South Wales, Australia. 2010-09-30T06:07:28.915Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2143 Current thermal comfort standards and the models underpinning them purport to be equally applicable across all types of building, ventilation, occupancy pattern and climate zone. A recent research project sponsored by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE, RP-884) critically evaluated these assumptions by statistically analysing a large database of research results in building comfort studies from all over the world (n=22,346). The results reported in this paper indicated a clear dependence of indoor comfort temperatures on outdoor air temperatures (instead of outdoor effective temperature ET* used in RP-884), especially in buildings that were free-running or naturally ventilated. These findings encourage significant revisions of ASHRAE’s comfort standard in terms of climatically relevant prescriptions. The paper highlights the potential for reduced cooling energy requirements by designing for natural or hybrid ventilation in many moderate climate zones of the world. 2010-09-01T23:20:29.204Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:9327 This paper outlines the methodology, application and analysis of a rapid urban stream assessment tool, the Rapid Riparian Assessment (RRA) within the Ku-ring-gai Council Local Government Area, Sydney. The tool was developed to improve the understanding of riparian processes and broader environmental condition with an urban context. The results assist environmental management through the identification of causes and processes of change and degradation, inturn allowing the ability to direct policy, strategy and operational resources. The RRA has been carried out in all streams under the management and control of Ku-ring-gai Council, in total 221 kilometres, incorporating 288 reaches were assessed. It was found that 61% have a condition rating of good or better. Only 1% of reaches assessed were rated as very poor. The results suggest that urban stream condition within this local government area is better than predicted for typical urban streams. This may be attributed to the large number of bushland corridors that help to maintain the riparian zone in conjunction with the geomorphology, predominately incised gullies dominated by Hawkesbury Sandstone, that is relatively robust to urban pressures, consequently remaining relatively un-impacted. Sensitivity testing of the methodology and attribute weightings confirms the effectiveness of this tool. 2010-08-31T19:10:22.305Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:9129 Little published detail exists regarding the range of natural hazards impacts experienced at the community level in Fiji, how these impacts interact and the cost (economic, environmental and social) they have. Impact assessments provide useful information to decision makers in all sectors, and enable them to make informed decisions regarding land-use planning, infrastructure planning and preparation for medical response. The availability of such information at a community level allows for detailed planning and can also encourage community ownership of hazard mitigation. Unfortunately, a lack of available methods to conduct such assessments hinders natural hazard planning. This paper outlines the methods to be employed in a PhD study currently underway to investigate the impacts of one natural hazard (tropical cyclones) in communities in Fiji. Methods include: interviews with members of affected communities to identify impacts; a questionnaire survey to determine the prioritisation of these impacts; and, interviews with government officials and other organisations involved in disaster management or response to collect existing data on impacts. The methods described here and the resulting data will contribute to the wider study to enhance understanding of natural hazard impacts in the communities affected. This understanding will then be used to develop processes to identify and measure impacts which can be employed before a disaster to highlight vulnerabilities (and focus mitigation), and after a disaster to direct response. 2010-08-09T01:00:06.539Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:8759 The 2004 Indian Ocean tsunami has demonstrated that large magnitude, destructive tsunami occur in areas close to Australia. The commitment by the Australian Federal Government to the development and installation of an Australian Tsunami Warning System is a vital element in helping to keep Australian coastal communities and public and private infrastructure and assets safe from tsunami. However, the physical components of the warning system are only one element of making Australia safe. The other, perhaps more important element, is preparedness and response. Emergency Management Australia and the State Emergency Services are the agencies tasked with the responsibility of evacuating coastal communities if required. The success or otherwise of public response to tsunami warnings will be dependent of their understanding of tsunami hazard and risk. We provide selected results from a pilot investigation into public awareness of tsunami risk in the Sydney region a fundamental necessity for developing appropriate risk mitigation strategies. Our questionnaire survey of members of the general public and coastal council officers indicates that little has been learned since the December 2004 Indian Ocean tsunami disaster. This presentation provides a summary of what the public knows and importantly, does not know with respect to tsunami. We make a series of recommendations to assist responsible organisations in thinking about risk mitigation. 2010-06-25T16:20:39.156Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1117 Tourism is a popular catalyst for socio-economic development in many small island developing states (SIDS). However, exposure to damaging natural hazards in these nations exacerbates the tourism industry's intrinsic vulnerabilities. The reliance of SIDS on the income-multiplying benefits of tourism make the sustainability of the industry imperative, but the vulnerability of tourism to natural hazards endangers this sustainability. The perception of natural hazards held by tourism managers may influence the adoption of appropriate mitigation and preparedness measures and thus, decrease vulnerability and increase sustainability. Accordingly, this paper presents the method and findings of a pilot study into the accuracy of natural hazard perceptions held by members of the tourism industry in Tanna, an island in the South West Pacific SIDS of Vanuatu. The study finds that perceptions are generally accurate within the industry. However, there is scope for improvement in the prevalence of accurate perceptions. It is recommended that this be achieved through the development and implementation of a comprehensive natural hazards awareness strategy, details of the format and structure of such a strategy are detailed within. 2010-05-30T23:34:00.330Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:3188 Fences are ubiquitous in all settled areas of rural Australia and those older than 50 years qualify as historic heritage. However, the linear nature of fences (kilometres long and only millimetres wide), complicated by joint ownership on boundaries, pose severe challenges for heritage management. They are threatened by combinations of decay, termite attack, fire, flood, and replacement or maintenance. These threats are illustrated using several examples of rare heritage fences (hedge, dog-leg, pisé, lace, chock-and-log and stubb). There is currently no framework for determining which fences are important heritage. Despite this, a very few fences have been restored slightly, some relocated to museums, and a very few replicas constructed of famous fences (e.g. Rabbit Proof Fence No. 1 in Western Australia). However, for most fences considered to be heritage, the future is bleak and detailed recording appears the only practicable option. 2010-05-19T06:34:21.935Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:8086 In the contemporary higher education system there is growing interest in, and debate about, the need to strengthen and sustain the relationships between teaching and research. While there are multiple and varied explanations about these relationships, most acknowledge the importance of designing learning activities that explicitly develop the research-teaching nexus: a methodology known as research-led teaching. The paper illustrates the integration of a research-led teaching approach in an online context, using an ocean (climate) model simulation activity in two undergraduate units as a case study. The modelling activity draws on disciplinary research as the underpinning content and stimulus for learning, and incorporates tasks designed to simulate scientific thinking as well as facilitate understanding of abstract concepts about the ocean (and atmosphere) climate system. It also demonstrates a research-led teaching activity that has been successfully applied in different disciplinary contexts, physical geography (atmospheric science sub-discipline) and physics. 2010-05-08T04:00:22.602Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:7390 Studies of heat-related mortality have been predominantly based on analyses of underlying cause of death as the single indicator of a population's vulnerability to high temperatures. Examination of both underlying and associated causes of death could provide a more comprehensive understanding of the population at risk. This study analyzes the impact of high temperatures on mortality in Sydney, Australia, during the warmer six months (October–March) between 1993 and 2004, using the underlying and associated cause of death due to all-cause, circulatory, and respiratory disease. Some mortality datasets were also divided into two age groups, 0–64 and 65+. A generalized linear model assuming negative binomial distribution was constructed for the daily mortality counts using daily maximum temperature and hourly maximum concentrations of ozone (O₃) and particulate matter (PM₁₀) as covariates. With the air pollution terms in a model, the change in mortality was estimated to be between 4.5% and 12.1% for a 10 °C increase in maximum daily temperature, depending on mortality dataset. When air pollutants were removed from a model, the above mortality percentages changed by −1.1% to 0.9%. When both underlying and associated causes of death were considered, the effect remained the same or became lower. Maximum temperature has been found to have a significant effect on mortality in Sydney, with PM₁₀ and O₃ confounding the association. 2010-03-16T07:21:13.319Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:7148 Recent technological advances in the study and dating of both land and marine glacial geologic features combined with improvements in both glaciological and post-glacial isostatic rebound modelling have led to significant improvements in our knowledge and understanding of the Antarctic Ice Sheets at the Last Glacial Maximum (LGM) and their subsequent changes throughout the Holocene. Here we review the geological evidence for the extent and timing of the maximum advance of the East and West Antarctic Ice Sheets and the ice cover of the Antarctic Peninsula during the most recent glacial cycle. We also discuss evidence for the rate and timing of Holocene Ice Sheet retreat. Geological data provide a very important ‘first-hand’ record of ice-sheet changes over a range of time periods. They are also useful for constraining and improving models which then have the potential to both fill in the gaps for which geological data are unavailable, and to make predictions of the future. Inspection of the geological record allows us to form qualitative scenarios concerning glacial history. Numerical modelling has been used on several occasions to test such hypotheses. We discuss such numerical studies, indicating both their importance and limitations in order to develop quantitative ideas about the late Quaternary history of the ice sheet. An important environmental aspect of Antarctica's glacial history is its contribution to global sea level rise since the LGM. The past decade has seen the range of estimates (from reconstructions based solely on geological evidence, on glaciological modelling constrained by geology and on modelling of the isostatic rebound) change from 0.5–38 m sea level equivalent to 5.9–19.2 m. Although the convergence of estimates is encouraging, there is a need for further glaciological modelling to take full account of the constraints placed on LGM ice expansion, particularly in East Antarctica, by new geological evidence. 2010-02-25T06:10:48.786Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:401 The distribution and persistence of water repellence was altered by low severity fire and subsequent rain in soil supporting eucalypt woodland on sandstone terrain in Sydney, south-eastern Australia. Water drop penetration times were recorded to depths of 0.08 m in situ 9 months before the experimental fire, immediately after fire, 4 weeks later when rainfall had modified the soil surface but the soil was dry, and 5 weeks after the fire when the soil was moist. Spatial variation in water repellence was high in all cases except immediately after the fire, when soil was almost uniformly strongly repellent to 0.03 m depth, and less uniformly repellent at 0.04–0.06 m depth. Heavy rain moved litter, ash, and mineral soil, modifying the soil surface into microtopographic units including litter dams, microterraces, and other areas with differing proportions of litter, bare soil, and gravel. Post-rain water drop penetration measurements were taken on and beneath these different surface conditions, in order to investigate the possible contribution of water repellence to the formation and maintenance of litter dams and microterraces characteristic of this terrain after fire. Water repellence did not appear to be directly correlated with the presence or absence of surface litter. Results suggest the long-term and spatially variable water repellence found in soils associated with vegetation dominated by eucalypts in Australia is maintained by factors different from those causing extreme and uniform water repellence after fire. Variable water repellence at the soil surface and within the profile may contribute to differential survival of seedlings after fire. The possible breakdown of water repellent compounds formed after fire and the distribution and development of hydrophobic biotic structures including fungal hyphae and proteoid roots need to be investigated. 2010-01-27T23:28:37.474Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:472 Fluvial landforms provide a physical template upon which to appraise biophysical relationships along river courses. In this study, the spatial pattern of organic matter storage along the Kangaroo River, NSW, is related to geomorphic controls that operate at a range of scales within a nested hierarchy. This snapshot study of CPOM storage found that at the catchment scale the longitudinal pattern of coarse particulate organic matter (CPOM) storage is dependent on the type and downstream pattern of River Styles. At the reach scale, CPOM storage is dependent on the geomorphic unit structure and physical heterogeneity of the river, and associated energy conditions along the reach. At the geomorphic unit scale, CPOM storage capacity is related to the position of geomorphic units relative to the thalweg (i.e. flow characteristics) and associated roughness attributes. At the hydraulic unit scale, CPOM storage capacity is related to local flow velocity and substrate characteristics (clast size and distribution). 2010-01-27T23:27:49.923Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:476 1. The River Styles framework is a geomorphic approach to the classification of river types, assessment of the physical condition of rivers, and planning of physical rehabilitation. However, the linkages between River Styles and aquatic biodiversity conservation are still only weakly developed. 2. In this study, 41 sites in the Bega River basin in New South Wales, Australia, were classified according to River Style and geomorphic condition, and surveyed for four biological assemblages: diatoms, aquatic and semi-aquatic macrophytes, aquatic macroinvertebrates and fish. 3. Each assemblage differed significantly among River Styles. However, in the case of diatoms and fish, these differences could be accounted for by geographic clustering of sites in the same River Style, and a tendency for River Styles to occupy particular altitudinal zones and sizes of streams. This result was attributed to the overriding influences of water quality on diatoms and of altitude-related variation in water temperature and distance from the ocean on fish. For macrophytes and macroinvertebrates, geomorphic river type appeared to exert a direct influence, probably via variation in physical habitat characteristics. 4. Geomorphic condition, judged as good, moderate or poor by reference to the inferred natural condition of each River Style, was also significantly associated with differences in biological assemblages other than fish. Twice as many taxa appeared to favour sites in good geomorphic condition as favoured sites in poor condition. Many of the taxa associated with sites in poor condition are alien taxa introduced to Australia since European settlement. 5. These findings imply that protection of reaches that are in good geomorphic condition is likely to be critical for the maintenance of indigenous biodiversity, and that rehabilitation of geomorphic condition can assist in the rehabilitation of native riverine biota. 2010-01-27T23:27:47.536Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:477 Geographic concerns for spatial relationships lie at the heart of geomorphic applications in environmental management. The way in which landscape compartments fit together in a catchment influences the operation of biophysical fluxes, and hence the ways in which disturbance responses are mediated over time. These relationships reflect the connectivity of the landscape. A nested hierarchical framework that emphasizes differing forms of (dis)connectivity in catchments is proposed. This field-based geomorphic tool can be used to ground the application of modelling techniques in analysis of catchment-scale biophysical fluxes. 2010-01-27T23:27:46.288Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:497 Australia and New Zealand have been at the forefront of many advances in river management through policy and legislative initiatives and the introduction of participatory frameworks. In part this leadership role is a response to the pervasive extent and impact of post-colonial societies on Australasian environments. Core geographical concepts have contributed significantly to the increased recognition of a 'sense of place' in management practice. Grounded and authentic applications recognise explicitly the complexity of interactions across an array of biophysical and social scales. The contribution of geography to river management is particularly significant in the implementation of catchment-framed programmes, the development of generic scientific tools that can be used on a catchment-by-catchment basis, and the application of adaptive management principles that are operationalised within participatory frameworks. Failing to acknowledge geographical concepts can lead to a placeless universalism in river management that is unsustainable and unacceptable in biophysical and social terms. 2010-01-27T23:27:29.829Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:575 Fire-induced or enhanced soil water repellency is often viewed as a key cause of the substantial increases in runoff and erosion following severe wildfires. In this study, the effects of different fire severities on soil water repellency are examined in eucalypt forest catchments in the Sandstone Tablelands near Sydney, burnt in 2001 and 2003. At sites affected by different fire severities and in long-unburnt control sites, repellency persistence was determined in situ and in the laboratory for surface and subsurface soil samples (n=846) using the Water Drop Penetration Time (WDPT) test. All long-unburnt samples were found to be water repellent, with severe to extreme persistence (>900 s) being dominant for surface (0–2.5 cm) and slight to moderate persistence (10–900 s) for subsurface (2.5–5 cm) soil, indicating naturally very high ‘background’ levels of repellency. In contrast to the generation or enhancement of repellency usually reported following forest fires of similar severity in previous studies, burning caused widespread destruction of repellency. The mineral soil depth to which repellency was destroyed (0.5–5 cm) was found to increase with burn severity. Below this charred wettable layer, persistence of pre-existing water repellency increased. Two years after the fire, the frequency of extreme repellency persistence was reduced in the surface and subsurface. However, recovery to pre-fire repellency levels had not been achieved. The associated hydrological impacts of these fire effects are more complex than simply the enhancement of overland flow, runoff and soil erosion with increasing fire severity. For forest fires sufficiently severe to remove foliage and ground litter above already repellent soil, a more severe burn, in which there is destruction of surface soil repellency, would result in lower runoff response compared to a burn insufficiently severe to destroy surface repellency. During storms intense enough to saturate the wettable surface rapidly, this layer may, however, be removed by overland flow, with potentially severe implications for soil fertility and seedbed survival, post-fire ecosystem recovery, and downstream sedimentation and water quality. The results demonstrate that existing fire severity classifications are not well suited to predicting fire impacts on soil hydrological responses and highlight the need for a new fire severity evaluation scheme. A scheme encompassing not only foliage and ground cover status, but also changes to surface and subsurface soil hydrological properties, would provide a better prediction of the immediate hydrological effects of wildfires on catchments such as flash flooding and erosion, and also of their time-to-recovery than current classifications allow. Such a scheme could prove invaluable given the future increase in fire frequency and severity predicted for many regions. 2010-01-27T23:26:31.863Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:632 The downstream distribution of stream power is derived and analysed for 11 different streams in the upper Hunter River catchment, Australia. Stream long profiles were produced in a GIS environment using DEM data and catchment area–discharge analysis. These profiles were analysed using three approaches, namely long profile smoothing, curve fitting and a theoretical model. The methodology for deriving stream power profiles using these three approaches is discussed. The long profile smoothing method provides a good approximation of the subcatchment variability in stream power trends. The curve fitting method shows that higher-order exponential curves provide a better fit for long profile data. For the streams of the upper Hunter River catchment, second-order exponential curves fit well with significantly less error. The curve fitting method predicts a bimodal (upstream and midstream) distribution of stream power, which is a deviation from our earlier understanding of a single midstream peak. The theoretical approach provides a mathematical expression of the observed bimodal stream power distribution. The bimodal distribution emphasises the erosion potential of headwater reaches. The resultant stream power distribution provides a catchment-scale characterisation of the distribution of available energy in any given system. Using these approaches, the variability of stream power in headwater reaches is explained by discharge variability, while variability in midstream and downstream reaches is related to high variability in channel gradient. 2010-01-27T23:25:57.739Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:658 This paper examines the current health policy response to the management of vector-borne disease (VBD), specifically Ross River (RR) virus, in subtropical coastal Australia. It demonstrates the multi-dimensional nature of the VBD problem and considers the value of more sustainable policy responses. The paper provides an integrated exploration of the incidence of RR virus in the context of socio-biophysical interactions and change, climate variability, and possible enhanced threat due to climate change. The study focuses on two subtropical coastal case study regions in Australia. Collectively, the existing and emerging socio-biophysical interactions in these regions raise questions as to the future risks and management of RR virus, while climate change adds a significant further dimension. The paper demonstrates the need for the incorporation of environmental planning elements, particularly attention to strategic assessment and planning, into the traditional suite of health policy responses given the multi-dimensional nature of the problem and evident socio-biophysical environmental change. 2010-01-27T23:25:41.233Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:931 Intense rainfall following wildfire can cause substantial soil and sediment redistribution. With concern for the increasing magnitude and frequency of wildfire events, research needs to focus on hydrogeomorphological impacts of fire, particularly downstream fluxes of sediment and nutrients. Here, we investigate variation in magnetic enhancement of soil by fire in burnt eucalypt forest slopes to explore its potential as a post-fire sediment tracer. Low-frequency magnetic susceptibility values (χ_lf) of <10 µm material sourced from burnt slopes (c. 8·0-10·4 × 10⁻⁶ m³ kg⁻¹) are an order of magnitude greater than those of <10 µm material derived from long-unburnt areas (0·8 × 10⁻⁶ m³ kg⁻¹). Susceptibility of anhysteretic remanent magnetization (χARM) and saturation isothermal remanent magnetization (SIRM) values are similarly enhanced. Signatures are strongly influenced by soil and sediment particle size and storage of previously burnt material in footslope areas. Whilst observations indicate that signatures based on magnetic enhancement show promise for post-fire sediment tracing, problems arise with the lack of dimensionality in such data. Magnetic grain size indicators χ_fd%, χARM/SIRM and χ_fd/ARM offer further discrimination of source material but cannot be included in numerical unmixing models owing to non-linear additivity. This leads to complications in quantitatively ascribing downstream sediment to source areas of contrasting burn severity since sources represent numerical multiples of each other, indicating the need to involve additional indicators, such as geochemical evidence, to allow a more robust discrimination. 2010-01-27T23:22:21.473Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1013 A list with commentary on the top 15 papers about the Australian Quaternary. Written with a view to give an oversite of the Australian Quaternary before the 2007 INQUA Congress. 2010-01-27T23:21:26.495Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1111 This book reviews the major achievements that have been made in soil erosion and sediment redistribution research and management. It presents work from key players in river basin soil erosion and sediment redistribution, from sources to sinks, from field to riverbank, and from academia to policy and industry. It examines the developments made in three themes - measurement, modelling and management - and covers a variety of scales (in both time and space) and geographical locations. The book concludes by identifying future requirements for river management policies. 2010-01-27T23:20:19.430Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1321 The increase in asthma incidence, prevalence, and morbidity over recent decades presents a significant challenge to public health. Pollen is an important trigger of some types of asthma, and both pollen quantity and season depend on climatic and meteorological variables. Over the same period as the global rise in asthma, there have been considerable increases in atmospheric carbon dioxide concentration and global average surface temperature. We hypothesize anthropogenic climate change as a plausible contributor to the rise in asthma. Greater concentrations of carbon dioxide and higher temperatures may increase pollen quantity and induce longer pollen seasons. Pollen allergenicity can also increase as a result of these changes in climate. Exposure in early life to a more allergenic environment may also provoke the development of other atopic conditions, such as eczema and allergic rhinitis. Although the etiology of asthma is complex, the recent global rise in asthma could be an early health effect of anthropogenic climate change. 2010-01-27T23:17:58.459Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1426 3 page(s) 2010-01-27T23:16:47.437Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1454 This book reviews the major achievements recently made in soil erosion and sediment redistribution research and management and identifies future requirements. 2010-01-27T23:16:29.768Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1465 This paper addresses the philosophical question: ‘why rehabilitate urban river systems?’ within an Australian context. Rehabilitation of river systems has become an important objective of many local, state and national governments around the world, who allocate substantial investment into various river projects. An understanding of the various factors influencing stream condition and potential rehabilitation options is essential in order to determine how the process is undertaken, and how success is measured. This paper examines the triple bottom line (economic, social and environmental) factors that influence decisionmaking with respect to urban stream rehabilitation and management and considers their relative value and importance. 2010-01-27T23:16:22.148Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1469 This study uses GIS techniques to examine the spatial distribution of stream power along major streamlines in the Lane Cove catchment in northern Sydney, Australia. Channel gradient estimates derived from a 5 m resolution digital elevation model (DEM) are combined with streamflow data to estimate stream power along river courses. Stream power and its constituent components are then related to a detailed field-based assessment of sediment storage along the trunk stream and primary tributaries. At the catchment scale, sediment storage per unit length decreases as channel gradient and gross stream power increase. However, local controls such as variability in valley width and occurrence of confluence zones exert a greater influence upon sediment storage, disrupting systematic catchment-wide relationships. The total volume of storage along each streamline has a strong linear relationship to the area of the subcatchment, but the distribution of sediment along streamlines varies between subcatchments. The GIS framework employed in this project allows generation of continuous, empirical data, thereby providing catchment-specific predictive capacity that can accompany theoretical approaches to stream power modelling. 2010-01-27T23:16:19.357Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1475 This study investigated the effect on thermal perception and thermophysiological variables of controlled metabolic excursions of various intensities and durations. Twenty-four subjects were alternately seated on a chair or exercised by walking on a treadmill at a temperature predicted to be neutral at sedentary activity. In a second experimental series, subjects alternated between rest and exercise as well as between exercise at different intensities at two temperature levels. Measurements comprised skin and oesophageal temperatures, heart rate and subjective responses. Thermal sensation started to rise or decline immediately (within 1 min) after a change of activity, which means that even moderate activity changes of short duration affect thermal perceptions of humans. After approximately 15–20 min under constant activity, subjective thermal responses approximated the steady-state response. The sensitivity of thermal sensation to changes in core temperature was higher for activity down-steps than for up-steps. A model was proposed that estimates transient thermal sensation after metabolic step-changes. Based on predictions by the model, weighting factors were suggested to estimate a representative average metabolic rate with varying activity levels, e.g. for the prediction of thermal sensation by steady-state comfort models. The activity during the most recent 5 min should be weighted 65%, during the prior 10–5 min 25% and during the prior 20–10 min 10%. 2010-01-27T23:16:11.386Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1476 Concentrations of tropospheric ozone often exceed Australian air quality goals in Sydney during summer. However, features in the occurrence of ozone in Sydney are yet to be fully explained. Meteorological conditions associated with ozone episodes in Sydney are caused by complex interactions between synoptic and meso-scale processes. This paper discusses the meteorological influences behind ozone pollution episodes in Sydney. A synoptic climatology of ozone episodes in Sydney was generated using multivariate statistical techniques, including principal component analysis (PCA) and a two-stage cluster analysis, to classify days into meteorologically homogeneous synoptic categories. Surface and upper air meteorological data for warm months (Oct–Mar)over a 10-year period were used as input into the statistical analyses. Eleven synoptic categories were identified in Sydney during the warm season and ozone concentrations associated with each of the synoptic categories were investigated. One synoptic category was found to be associated almost exclusively with high pollution concentrations. High ozone concentrations were found to be associated with a high-pressure system located in the middle to eastern Tasman Sea producing light northwesterly gradient winds, an afternoon sea breeze, high afternoon temperatures, a shallow mixing height at the coast and warming aloft during the day. Over 90% of all days exceeding current air quality goals for ozone in Sydney fell within the synoptic category associated with the highest ozone concentrations. It is envisaged that results from this research will be useful to Australian regulatory bodies from both a forecast point of view and for the siting of future ozone precursor sources in Sydney and surrounding regions. 2010-01-27T23:16:11.373Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1529 Like most Sydneysiders, I have become increasingly concerned with the gradual reduction of the water stored in Sydney's catchments. At the time of writing, current water storage levels are only 42.7 per cent of maximum levels, a situation that has prevailed for more than a year. The water supply issue was brought sharply into focus in July 2005, when the NSW government announced that they would build a desalination plant to supply one-third of the fresh water supply to Sydney. However, following extensive public debate, the NSW Government announced in February 2006 that they would shelve plans for the plant, on the condition that planning for a desalination plant would be re-instated immediately if dam storage levels fall below 30 per cent. Nevertheless, the proposed desalination plant is an uncomfortable reality of the cumulative impact of our lifestyles. The continued economic and population growth in Sydney (approximately 570 people per week, ABS 2006), coupled with the release of land for an additional 160,000 houses in the north-west and southwest sectors of Sydney, will compound the pressure on water resources, meaning that the 'do nothing' or 'she'll be right' attitude is clearly no longer an option. 2010-01-27T23:15:23.871Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1528 Spring-fed streams that deposit tufa (ambient temperature freshwater calcium carbonate deposits) in the tropics of northern Australia are influenced strongly by perennially warm water temperatures, high evaporation rates, and monsoon driven high-magnitude floods. This paper presents an environmental model that will aid interpretation of fossil fluvial tufas throughout monsoonal Australia. In the Barkly karst, northern Australia, tufas form in dam, cascade and pool/waterhole geomorphic environments. Each environment is represented in the morphostratigraphical record by a specific combination of tufa geomorphic units and facies associations. A diverse array of tufa facies is present, including microphytic, larval, calcite raft, macrophytic and allochthonous types. Preservation of particular Barkly karst tufa facies is thought to reflect the strength of monsoonal floods. A strong monsoon is represented by an abundance of flood indicators such as the allochthonous phytoclastic, lithoclastic and intraclastic tufa facies. Conversely, evidence of weak monsoons or a prolonged absence of floods may include oncoids, calcite rafts and thick accumulations of fine carbonate sediments. The history of the Australian monsoon is not fully understood. However, fossil tufa deposits, which record terrestrial climate information, have been preserved throughout northern Australia and hold great potential for reconstructing the region's climate history. Fossil tufa sequences at two Barkly karst sites have been interpreted using the new model. It can be applied to other Barkly karst fossil tufas as well as those in similar environments elsewhere in the world. 2010-01-27T23:15:23.853Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1630 The article reviews the book "Climate Change and the Indoor Environment: Impacts and Adaptation," by J. Hacker, M. Holmes, S. Belcher and G. Davies. 2010-01-27T23:14:10.577Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1631 The first guidelines for thermal comfort in buildings in The Netherlands were developed in the late 70s and in the 80s. They were based on the PMV-PPD relationship. In this article new guidelines are presented, based on the international research on adaptive thermal comfort. Two building/climate types are introduced: “Alpha” and “Beta”, analogous to the categories in the field studies on adaptive thermal comfort. For each building/climate type operative indoor temperature limits are given as a function of the running mean outdoor temperature and classified according to NPR-CR 1752. Finally some initial temperature simulations are shown, the results of which are plotted in the new comfort zone. 2010-01-27T23:14:10.572Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1717 Cyclone Larry crossed the Coral Sea in mid-March 2006, developing into a severe category five as it approached the coast south of Cairns. The eye of Larry crossed the coast between 6.20 and 7.20 am on Monday 20th March (Bureau of Meteorology 2006). Given Larry’s magnitude, it would not have been unreasonable to expect devastation of the settlements in its path, with many deaths and injuries. However, there were no deaths and very few injuries. We seek to determine whether this is a reflection of a well prepared and knowledgeable community. We carried out a survey of residents in rural communities in and around Innisfail a week after Larry. This article shows that the impacted communities were, in a very Australian way, well-prepared having generally experienced other severe cyclones. While longer term post-cyclone recovery may be a difficult time for these rural communities, in our opinion their preparations and responses to warnings were appropriate and undoubtedly saved lives and injuries and lessened the overall impact. 2010-01-27T23:13:10.717Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1718 Selected results from a pilot investigation into public awareness of tsunami risk in the Sydney region are presented. This is fundamentally necessary for developing appropriate risk mitigation and preparedness strategies. The questionnaire survey of members of the public and coastal council officerâ¿¿s indicates that little has been learned since the December 2004 Indian Ocean tsunami disaster. The findings show that the strategy of Emergency Management Australia for developing awareness and building capacity are both timely and appropriate. 2010-01-27T23:13:10.701Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1745 An apparent error was detected in the calculation of windchill equivalent temperatures (WCETs) in the 'new' chart and corresponding equation that were adopted in 2001 by the weather services in the United States and Canada. The problem is caused by significant discontinuities in WCETs at the assumed 'calm' wind speed condition of 1.34 m s⁻¹. As a result, published WCETs are not equal to, as they should be by definition, but are lower than air temperatures at the assumed calm wind speed condition. This inconsistency further propagates to higher wind speeds beyond the assumed calm condition. In this paper, a straightforward correction is proposed to circumvent these inconsistencies of the new windchill. The proposed correction makes this transition gradual rather than abrupt by applying it to the expression used for estimating the effects of wind on the convective heat exchange coefficient between humans and their cold and windy environment. 2010-01-27T23:12:53.257Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1916 Ross River virus (RRV) is the most important vector-borne disease in Australia. The National Notifiable Diseases Surveillance System has confirmed that its incidence is often greatest in the state of Queensland, where there is a clear seasonal pattern as well as interannual variability. Previous studies have examined relationships between large-scale climate fluctuations (such as El Niño Southern Oscillation) and vector-borne disease. No previous study has examined such relationships with the Quasi-Biennial Oscillation (QBO), another large-scale climate fluctuation. We employ time-series analysis techniques to investigate cycles inherent in monthly RRV incidence in Queensland, Australia, from January 1991 to December 1997 inclusive. The presence of a quasi-biennial cycle in the RRV time series that is out of phase with the climatic QBO is described. Quantitative analyses using correlograms and periodograms demonstrate that the quasi-biennial cycle in the RRV time series is statistically significant, at the 95% level, above the noise. Together with the seasonal cycle, the quasi-biennial cycle accounts for 77% of the variance in Queensland RRV cases. Regression analysis of QBO and summer rainfall in three climatic zones of Queensland indicates a significant association between QBO and rainfall in the subtropical southeastern part of the state. These results suggest an indirect influence of the QBO on RRV incidence in Queensland, via its influence on climate in this region. Our findings indicate that the QBO may be a useful predictor of RRV at several months lead, and might be used by public health authorities in the management and prevention of this disease. 2010-01-27T23:10:34.112Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1940 1 page(s) 2010-01-27T23:10:16.913Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1961 In the absence of empirical outdoor thermal comfort studies it has been widely assumed that indoor thermal comfort theory generalises to outdoor settings without modification. Many indoor models were developed to describe thermal discomfort, not stress, therefore their relevance to conditions that vary greatly from neutrality, as many outdoor climatic conditions do, has not been critically validated in the field to date. The thermal comfort of 1018 subjects in outdoor and semi-outdoor locations in subtropical Sydney was investigated by a questionnaire and a comprehensive package of micro-meteorological instruments. The thermal neutrality in terms of the thermal comfort index OUT_SET* of 26.2°C was significantly higher than the indoor SET* counterpart of 24°C (ASHRAE Trans. 92 (1986) 709). 2010-01-27T23:09:58.447Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1962 This paper develops a GIS-based integrated approach to risk assessment in natural hazards, with reference to bushfires. The challenges for undertaking this approach have three components: data integration, risk assessment tasks, and risk decision-making. First, data integration in GIS is a fundamental step for subsequent risk assessment tasks and risk decision-making. A series of spatial data integration issues within GIS such as geographical scales and data models are addressed. Particularly, the integration of both physical environmental data and socioeconomic data is examined with an example linking remotely sensed data and areal census data in GIS. Second, specific risk assessment tasks, such as hazard behavior simulation and vulnerability assessment, should be undertaken in order to understand complex hazard risks and provide support for risk decision-making. For risk assessment tasks involving heterogeneous data sources, the selection of spatial analysis units is important. Third, risk decision-making concerns spatial preferences and/or patterns, and a multicriteria evaluation (MCE)-GIS typology for risk decision-making is presented that incorporates three perspectives: spatial data types, data models, and methods development. Both conventional MCE methods and artificial intelligence-based methods with GIS are identified to facilitate spatial risk decision-making in a rational and interpretable way. Finally, the paper concludes that the integrated approach can be used to assist risk management of natural hazards, in theory and in practice. 2010-01-27T23:09:58.445Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:1967 Based on principles from the ecological literature, a semi-quantitative framework to assess geomorphic river condition is outlined. Guiding principles that underlie the framework include the need to compare like-with-like, selection of appropriate ‘natural’ reference conditions for differing types of river, framed in terms of their natural range of variability, and measurement of parameters that are relevant for each type of river. Solid understanding of river character and behaviour along with assessment of capacity for adjustment, and appraisal of river evolution, including responses to human disturbance, are core components of the framework. Reference conditions are defined for each type of river using ergodic reasoning. The procedure for assessing geomorphic river condition has three steps: (1) identify the type of river, termed River Style, and its capacity for adjustment within its valley setting; (2) assess river evolution as a basis for identifying irreversible geomorphic change and a ‘natural’ reference condition; (3) determine and explain the geomorphic condition of each reach in a catchment. Application of the procedure is demonstrated for reaches of an alluvial and a confined River Style in Bega catchment on the South Coast of New South Wales, Australia. 2010-01-27T23:09:54.452Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2003 Fuel loads in forest areas are dependent on vegetation type and the time since the last fire. This paper reports a study on the feasibility of using remotely sensed data to estimate vegetative fuel loads. It describes two methods for estimating fuel loads using Landsat TM data based on equations describing litter accumulation and decomposition. The first method uses classification techniques to predict vegetation types coupled with fire history data to derive current fuel loads. The second method applies a canopy turnover rate to estimate litterfall and subsequently accumulated litter from biomass, thus utilising the dominant influence of canopy on remotely sensed data. Both methods are compared with data collected from Popran National Park in coastal New South Wales. The amounts of litter calculated with the biomass method were similar to field results, but the classification method was found to overestimate fuel loads. A sensitivity analysis investigated the impact of varying the vegetation constants and rates used in the fuel estimates to simulate uncertainty or error in their values. The biomass method was less subject to uncertainties and has potential for estimating fuel quantities to provide useful spatial information for fire managers. 2010-01-27T23:09:22.845Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2006 Spring-fed rivers of the Barkly karst in tropical northern Australia form an array of tufa and related freshwater carbonate deposits. One of these deposits, calcite rafts, is precipitated at the water–air interface principally as a consequence of CO₂ degassing and evaporation. Calcite rafts have been reported in cave environments but have not been described in detail from fluvial systems. Observations using scanning electron microscopy coupled with water chemistry data reveal that they form by a combination of physical, chemical and biological processes. They grow downwards into the water column and form a dentate lower surface, while a flat upper surface occurs at the water–air interface. The rafts are readily inhabited by microorganisms, particularly diatoms, which frequently become entombed by calcite as the rafts develop. The decay of the biological material leaves voids, creating a pock-marked texture. The rafts are subject to secondary calcite growth along the crystal edges. Once they become submerged in the water column after disturbance of the water surface, they may become completely covered by this overgrowth, creating a homogeneous veneer. The rafts form in quiescent settings, principally behind tufa dams in large, lake-like water bodies along each river. Therefore, they can be used in conjunction with adjacent exposures of other tufa facies to decipher palaeohydrological conditions. Although the rafts are extremely thin and fragile, they are readily preserved within fossil waterhole facies, and their occurrence has been identified in rocks from the Quaternary to the Tertiary. 2010-01-27T23:09:21.558Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2040 Human activities are resulting in increases in atmospheric greenhouse gases, such as carbon dioxide, and changes in global climate. These, in turn, are likely to have had, and will continue to have, impacts on human health. While such impacts have received increasing attention in recent years, the impacts of climate change on aeroallergens and related allergic diseases have been somewhat neglected. Despite this, a number of studies have revealed potential impacts of climate change on aeroallergens that may have enormous clinical and public health significance. The purpose of this review is to synthesize this work and to outline a number of research challenges in this area. There is now considerable evidence to suggest that climate change will have, and has already had, impacts on aeroallergens. These include impacts on pollen amount, pollen allergenicity, pollen season, plant and pollen distribution, and other plant attributes. There is also some evidence of impacts on other aeroallergens, such as mould spores. There are many research challenges along the road to a more complete understanding of the impacts of climate change on aeroallergens and allergic diseases such as asthma and hayfever. It is important that public health authorities and allergy practitioners be aware of these changes in the environment, and that research scientists embrace the challenges that face further work in this area. 2010-01-27T23:08:51.072Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2043 Heard Island (73°30' E, 53°05' S) is an isolated island in the sub-Antarctic located in a region of strong westerly winds. The dominant topographic feature is a large glaciated volcano, which peaks at 2,745 m in altitude. Only limited meteorological information exists for the island, within complete records from a station at Atlas Cove covering the period 1948 to 1954, and from a station at The Spit from 1992 onwards. We present the results of wind observations that were conducted on Dovers Moraine at the eastern end of Heard Island over the 2000/2001 summer, with the aim of characterising local winds at this location on the island. Wind was measured using a Woelfle-type mechanical wind recorder. Wind speed was comparable, and on occasions stronger, at this location compared to simultaneous records at the western end of the island. Winds were predominantly from the south-south-west, or north-north-west to north. A number of periods of relatively low wind speed coincided with repeated wind direction patterns, which we associate with the surface signature of von Karmanvortices. Results from this study suggest there are significant topographically-generated differences in wind characteristics between the eastern and western ends of the island. 2010-01-27T23:08:49.800Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2066 Recently accepted revisions to ASHRAE Standard 55—thermal environmental conditions for human occupancy, include a new adaptive comfort standard (ACS) that allows warmer indoor temperatures for naturally ventilated buildings during summer and in warmer climate zones. The ACS is based on the analysis of 21,000 sets of raw data compiled from field studies in 160 buildings located on four continents in varied climatic zones. This paper summarizes this earlier adaptive comfort research, presents some of its findings for naturally ventilated buildings, and discusses the process of getting the ACS incorporated into Standard 55. We suggest ways the ACS could be used for the design, operation, or evaluation of buildings, and for research applications. We also use GIS mapping techniques to examine the energy-savings potential of the ACS on a regional scale across the US. Finally, we discuss related new directions for researchers and practitioners involved in the design of buildings and their environmental control systems. 2010-01-27T23:08:33.361Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2067 Groundwaters feeding travertine-depositing rivers of the northeastern segment of the Barkly karst (NW Queensland, Australia) are of comparable chemical composition, allowing a detailed investigation of how the rate of downstream chemical evolution varies from river to river. The discharge, pH, temperature, conductivity and major-ion concentrations of five rivers were determined by standard field and laboratory techniques. The results show that each river experiences similar patterns of downstream chemical evolution, with CO₂ outgassing driving the waters to high levels of calcite supersaturation, which in turn leads to widespread calcium carbonate deposition. However, the rate at which the waters evolve, measured as the loss of CaCO₃ per kilometre, varies from river to river, and depends primarily upon discharge at the time of sampling and stream gradient. For example, Louie Creek (Q = 0·11 m³ s⁻¹) and Carl Creek (Q = 0·50 m³ s⁻¹) have identical stream gradients, but the loss of CaCO₃ per kilometre for Louie Creek is twice that of Carl Creek. The Gregory River (Q = 3·07 m³ s⁻¹), O'Shanassy River (Q = 0·57 m³ s⁻¹) and Lawn Hill Creek (Q = 0·72 m³ s⁻¹) have very similar gradients, but the rate of hydrochemical evolution of the Gregory River is significantly less than either of the other two systems. The results have major implications for travertine deposition: the stream reach required for waters to evolve to critical levels of calcite supersaturation will, all others things being equal, increase with increasing discharge, and the length of reach over which travertine is deposited will also increase with increasing discharge. This implies that fossil travertine deposits preserved well downstream of modern deposition limits are likely to have been formed under higher discharge regimes. 2010-01-27T23:08:33.314Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2068 The dispersal of metalliferous pollution from several spoil heaps produced during 20th century copper mining in the Gruben River valley, Namibia is examined. The Gruben River flows through an extremely arid environment with an average rainfall of ˜25 mm p.a. The potential for physical and chemical remobilisation of Cu, Zn and Ni is assessed by examining the spatial and temporal distribution of metal-contaminated sediment deposited within the confines of the channel. The relationships between metal content, grain size, geomorphic environment and the downstream distribution of metals are discussed. The phase-specific heavy metal concentrations of sediments, collected as part of the downstream sampling programme, are also examined using progressively more aggressive sequential acid extractions. In addition, metal concentrations are compared with Dutch guidelines for soil contamination to ascertain the extent of environmental risk. Total metal concentrations show that the Gruben valley is highly contaminated, particularly with respect to Cu and Ni concentrations, which exceed Dutch target values for Cu (36 ppm) in 94.7% and Ni (35 ppm) in 90.5% of samples, respectively. Zn concentrations are much lower with only 6.3% of the samples exceeding the target value (140 ppm). As might be expected, the metal–sediment concentrations of Cu are the most highly elevated, with a peak value of 10,500 ppm being recorded from material collected from suspended sediment transported during a minor flow event that occurred in March 1999. Lower energy and fine-grained sedimentary environments are shown to be clearly associated with higher metal concentrations. Sequential extractions of metals show that of the three principal elements considered in this study, only a negligible proportion of Cu (0.41%) is held in the exchangeable phase. Ni and Zn were below detection limits. Although the total metal concentrations in the Gruben River valley sediments are extremely high and are in themselves a concern, the small percentage of metals held in the exchangeable phase and the low potential for remobilisation under the arid conditions would suggest that they pose only a minor risk to the environment. 2010-01-27T23:08:31.981Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2076 Rivers show a remarkable diversity of character and behaviour in any catchment. Human activities have impacted profoundly on the inherent variability in patterns and rates of river adjustment, altering what rivers look like, how they behave, and the structure and function of acquatic ecosystems. This book outlines geomorphic considerations for river management and a generic set of proceedures, termed the River Styles framework, which provides a set of tools for interpreting river character, behaviour, condition, and recovery potential. 2010-01-27T23:08:25.592Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2103 Twenty-one land surface schemes (LSSs) performed simulations forced by 18 yr of observed meteorological data from a grassland catchment at Valdai, Russia, as part of the Project for the Intercomparison of Land-Surface Parameterization Schemes (PILPS) Phase 2(d). In this paper the authors examine the simulation of snow. In comparison with observations, the models are able to capture the broad features of the snow regime on both an intra- and interannual basis. However, weaknesses in the simulations exist, and early season ablation events are a significant source of model scatter. Over the 18-yr simulation, systematic differences between the models’ snow simulations are evident and reveal specific aspects of snow model parameterization and design as being responsible. Vapor exchange at the snow surface varies widely among the models, ranging from a large net loss to a small net source for the snow season. Snow albedo, fractional snow cover, and their interplay have a large effect on energy available for ablation, with differences among models most evident at low snow depths. The incorporation of the snowpack within an LSS structure affects the method by which snow accesses, as well as utilizes, available energy for ablation. The sensitivity of some models to longwave radiation, the dominant winter radiative flux, is partly due to a stability-induced feedback and the differing abilities of models to exchange turbulent energy with the atmosphere. Results presented in this paper suggest where weaknesses in macroscale snow modeling lie and where both theoretical and observational work should be focused to address these weaknesses. 2010-01-27T23:08:11.678Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2138 During the past two decades there have been a wide range of applications for decision-making linking multicriteria evaluation (MCE) and geographic information systems (GIS). However, limited literature reports the development of MCE-GIS software, and the comparison of various MCE-GIS approaches. This paper introduces an MCE-GIS program called MCE-RISK for risk-based decision-making. It consists of a series of modules for data standardisation, weighting, MCE-GIS methods, and sensitivity analysis. The program incorporates different MCE-GIS methods, including weighted linear combination (WLC), the technique for order preference by similarity to ideal solution (TOPSIS), and compromise programming (CP), enabling comparisons between different methods for the same decision problem to be made. An example of decision-making for determining priority areas for a bushfire hazard reduction burning is examined. After implementing the alternative MCE-GIS methods, and comparing final outputs and the computational difficulty involved in the analysis, WLC is recommended. Some caveats on using MCE-GIS methods are also discussed. Although the development of MCE-RISK and its application reported in this paper are specific to risk-based decision-making in natural hazards, the program can be used for other environmental decision applications, such as environmental impact assessment and land-use planning. 2010-01-27T23:07:49.667Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2150 2010-01-27T23:07:42.362Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2153 We apply a new tsunami vulnerability assessment method to two coastal villages in the Gulf of Corinth, Greece using the 7th February 1963 tsunami as a worse case scenario. In Akoli, 46.5% of all buildings are classified highly vulnerable (BV). Approximately, 26.3% of all households are located within buildings with a High BV classification whereas 85% of all businesses are located within buildings with a High BV classification and 13.7% of the population is located within buildings with a High BV classification. In Selianitika, 28.8% of all buildings are classified with a High BV and 11% of all households are located within buildings with a High BV classification. Also 29.3% of all businesses and 33.4% of all services are located within buildings with a High BV classification and 6.7% of the population is located within buildings with a High BV classification. We estimate the minimum costs of a hypothetical tsunami with a wave run-up (H(m)max) of +5 m. The results are considered significant because they have important implications for coastal risk assessment, resource allocation and disaster management planning. 2010-01-27T23:07:41.165Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2303 This paper seeks to address some of the limitations in previous statistical forecast models of tropical cyclogenesis through the development of a series of Poisson regression models on a 2° latitude × 5° longitude spatial grid and a monthly grid in time. The "Gray" parameters [low-level relative vorticity, vertical wind shear parameter, ocean thermal energy, (saturated) equivalent potential temperature gradient, and middle-troposphere humidity] were analyzed as potential predictors of tropical cyclogenesis for the Australian –southwest Pacific Ocean region. Various predictor lead times of up to 5 months were investigated, with the most significant Poisson regression models being cross validated, and the skill of their hindcasts evaluated. The Poisson regression model incorporating a combination of saturated equivalent potential temperature gradients at various leads was found to be the most skillful in hindcasting the temporal (phase and amplitude) variability of tropical cyclogenesis for the Australian –southwest Pacific region, with a correlation coefficient between the observed and cross-validated hindcast time series of 0.54 (significant at the 99% level), and a rootmean-square error 26% better than climatology. Models using the thermal (ocean thermal energy, saturated equivalent potential temperature gradient, and middle-troposphere humidity) and all (thermal plus low-level relative vorticity and vertical wind shear parameter) predictor variables showed the most skill in hindcasting the spatial distribution of cyclogenesis in this region. The model hindcast skill in predicting individual tropical cyclone occurrences and nonoccurrences was also examined. The all-Gray parameter Poisson regression model was found to correctly hindcast up to 72.6% of cyclogenesis events and nearly 70% of nonoccurrences in the Australian—southwest Pacific region. The model design enabled the investigation of tropical cyclogenesis on subregional/subseasonal scales, with promising model hindcast skill evident. The results presented herein suggest that useful and more detailed forecasts may be possible in the future in addition to those currently provided at the basin-wide and seasonal scales. 2010-01-27T23:05:53.377Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2368 Recent determinations of soil production from in situ cosmogenic nuclides indicate that production decreases exponentially with soil depth. This contrasts with a long-held assumption that maximum soil production occurs under a soil cover of finite depth. Sites in the Blue Mountains, Australia, show a sharp decrease of soil depth where vegetation changes from forested plateau surfaces to heath-covered spurs, and bands of bare rock in the heath suggest that soil production depends on presence of a finite depth of soil. The substrate varies from hard ferruginized sandstone to soft saprolite. In situ 10Be determinations indicate that apparent rates of erosion and soil production are greater under the relatively thin heath soil than under the thicker forest soil but, in contrast to other studies, these sites do not show significant depth-dependence of apparent soil production. The pattern reflects both hardness variation in the rock substrate and the effect of Late Quaternary climatic change. Optically stimulated luminescence (OSL) dating indicates that soil ≤30 cm depth is of Holocene age whereas the deeper soil is substantially older. The age-break coincides with a stone line interpreted as a former surface lag deposit. Assuming that pre-Holocene soil depths were 30 cm less than today, recalculated soil production tends to decrease with increasing depth. Soil production at this site requires soil cover but bare rock patches and vegetation comprise a shifting mosaic. In the long term, average rates of erosion and soil production decrease with increasing soil depth. 2010-01-27T23:05:20.382Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2374 The increase in asthma incidence, prevalence, and morbidity over recent decades presents a significant challenge to public health. Pollen is an important trigger of some types of asthma, and both pollen quantity and season depend on climatic and meteorologic variables. Over the same period as the global rise in asthma, there have been considerable increases in atmospheric carbon dioxide concentration and global average surface temperature. We hypothesize anthropogenic climate change as a plausible contributor to the rise in asthma. Greater concentrations of carbon dioxide and higher temperatures may increase pollen quantity and induce longer pollen seasons. Pollen allergenicity can also increase as a result of these changes in climate. Exposure in early life to a more allergenic environment may also provoke the development of other atopic conditions, such as eczema and allergic rhinitis. Although the etiology of asthma is complex, the recent global rise in asthma could be an early health effect of anthropogenic climate change. 2010-01-27T23:05:16.878Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2623 2010-01-27T23:02:23.680Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2656 Key aspects of environmental management exist within a legislative framework. The Rivers and Foreshores Improvement Act 1948 (NSW) and several Regional Environmental Plans created under the Environmental Planning and Assessment Act 1979 (NSW) make reference to ‘the top of the bank’ for defining areas of protected land adjacent to rivers, within which development consent may be required. It is an arbitrary term and its use within the Rivers and Foreshores Improvement Act 1948 (NSW) leads to confusion. This paper examines the range of definitions of ‘the top of the bank’ in respect of natural watercourses and aims to provide a more lucid and effective definition that will clarify existing ambiguities in legal interpretation. The paper examines the historical origins of the phrase ‘top of the bank’, finding that stereotyped Eurocentric views of what a river ‘should look like’ have impaired the legal definition for Australian rivers, thereby influencing common law and the development of statutory definitions. Judicial applications of the phrase ‘top of the bank’ are examined from a geomorphological perspective, demonstrating the misconceptions of the term in a legal context. The paper identifies the existence of widespread support for the need to protect land adjacent to rivers in the interests of environmental, economic and social sustainability. It concludes by calling for legislative reform that is both tailored to the individual site and consistent with overarching goals at the catchment scale. 2010-01-27T23:02:02.235Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2754 3 page(s) 2010-01-27T23:00:57.002Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2799 Action on disaster risk reduction can support sustainable development under climate change. 2010-01-27T23:00:23.053Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2808 This paper investigates oscillatory and propagating patterns of normalized surface and subsurface temperature anomalies (from the seasonal cycle) in the southwest Pacific Ocean using an extended empirical orthogonal function (EEOF) analysis. The temperature data (and errors) are from the Digital Atlas of Southwest Pacific upper Ocean Temperatures (DASPOT). These data are 3 monthly in time (January, April, July, and October), 2° × 2° in space, and 5 m in the vertical to 450-m depths. The temperature anomalies in the EEOF analysis are normalized by the objective mapping temperature errors at each grid point. They are also Butterworth filtered in the 3–7-yr band to examine interannual variations in the temperature field. The oscillating and propagating patterns of the modes are examined across four vertical levels: the surface, and 100-, 250-, and 450-m depths. The dominant mode EEOF (70% of the total variance of the filtered data) oscillates in a 4–4.5-yr quasi-periodic manner that is consistent with El Niño–Southern Oscillation (ENSO). Anomalies peak first at the surface in the subtropics between New Caledonia and Fiji (centered around 17°S, 177°E), then 6 months later in the tropical far west centered around the Solomon Islands (5°S, 153°–157°E), with a maximum at the base of the mixed layer (100 m) and upper thermocline (250 m), and then eastward in the northeast of the southwest Pacific region (0°–10°S, 160°E–180°). Mode 2 (25% variance of the filtered data) has a periodicity of 3–3.5 yr, with centers of action in all four vertical levels. The mode-2 patterns are consistent with variations in the subtropical gyre circulation, including the East Australian Current and its separation, and are continuous with the Tasman Front. Two spatial dipoles are apparent: (i) one in sea surface temperature (SST) at about 5°S, straddling west–east either side of the Solomon Islands, consistent with the classic Pacific-wide ENSO SST anomaly mode, and (ii) a subsurface dipole pattern, with centers in the Solomon Islands region at 100- and 250-m depths, and the western Tasman Sea (27°–33°S, 157°–161°E) at 250- and 450-m depths, consistent with dynamic changes in the gyre intensity. 2010-01-27T23:00:18.154Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2931 Short-term (contemporary) and long-term denudation rates were determined for the Blue Mountains Plateau in the western Sydney Basin, Australia, to explore the role of extreme events (wildfires and catastrophic floods) in landscape denudation along a passive plate margin. Contemporary denudation rates were reconstructed using 40 years of river sediment load data from the Nattai catchment in the south-west of the basin, combined with an analysis of hillslope erosion following recent wildfires. Long-term denudation rates (10 kyr-10 Myr) were determined from terrestrial cosmogenic nuclides, apatite fission track thermochronology and post-basalt flow valley incision. Contemporary denudation rates average several times lower than the long-term average (5·5 ± 4 mm kyr⁻¹ versus 21·5 ± 7 mm kyr⁻¹). Erosion of sediment following wildfires accounts for only a small proportion (5%) of the contemporary rate. Most post-fire sediment is stored on the lower slopes and valley floor, with the amount transported to the river network dependent on rainfall-run-off conditions within the first few years following the fire. Historical catastrophic floods account for a much larger proportion (35%) of the contemporary erosion rate, and highlight the importance of these events in reworking stored material. Evidence for palaeofloods much larger than those experienced over the past 200 years suggests even greater sediment export potential. Mass movement on hillslopes along valleys incised into softer lithology appears to be a dominant erosion process that supplies substantial volumes of material to the valley floor. It is possible that a combination of infrequent mass movement events and high fluvial discharge could account for a significant proportion of the discrepancy between the contemporary and long-term denudation rates. 2010-01-27T22:58:57.065Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2930 Previous literature has suggested that multiple peaks in sea level anomalies (SLA) detected by two-dimensional Fourier Transform (2D-FT) analysis are spectral components of multiple propagating signals, which may correspond to different baroclinic Rossby wave modes. We test this hypothesis in the South Pacific Ocean by applying a 2D-FT analysis to the long Rossby wave signal determined from filtered TOPEX/Poseidon and European Remote Sensing-1/2 satellite altimeter derived SLA. The first four baroclinic mode dispersion curves for the classical linear wave theory and the Killworth and Blundell extended theory are used to determine the spectral signature and energy contributions of each mode. South of 17°S, the first two extended theory modes explain up to 60% more of the variance in the observed power spectral energy than their classical linear theory counterparts. We find that Rossby wave modes 2–3 contribute to the total Rossby wave energy in the SLA data. The second mode contributes significantly over most of the basin. The third mode is also evident in some localized regions of the South Pacific but may be ignored at the large scale. Examination of a selection of case study sites suggests that bathymetric effects may dominate at longer wavelengths or permit higher order mode solutions, but mean flow tends to be the more influential factor in the extended theory. We discuss the regional variations in frequency and wave number characteristics of the extended theory modes across the South Pacific basin. 2010-01-27T22:58:57.052Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2941 Three types of valley morphology occur at the base of the escarpment in Bega catchment, on the South Coast of New South Wales, Australia. Each valley-setting contains a distinct river character and behaviour, namely cut and fill, bedrock-controlled discontinuous floodplain and fan. The character, behaviour and sedimentology of each base of escarpment river style are described and controls on their formation are assessed. Each river style operates under a certain set, or combination of boundary conditions that dictate the availability of accommodation space at the base of the escarpment. 2010-01-27T22:58:50.439Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2947 The development of soil classification and mapping by the USDA Soil Survey up to 1935 is considered. This involved the initial development of a scheme by Whitney based on soil productivity as reflected in the geology cum geomorphology. The thrust of this development was opposed by a very different Russian zonalistic approach, which was much more environmental in character. It was first advanced in the USDA by Coffey, but this was firmly rejected by Whitney. It was next proposed by Marbut, who in addition made use of Glinka's work, but made no references to Coffey's previous efforts. This was highly successful, for it not only took over the USDA system completely, but was expanded to form a global system of soil classification. However, the speed with which this occurred was such that numerous flaws and gaps had been created, which needed to be dealt with and this is considered in Part II. 2010-01-27T22:58:46.921Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:2949 The leadership of Kellogg, after that of Marbut, was marked by an initial period of consolidation during which a series of decisions were made that brought the Soil Survey much closer to the practical problems of agriculture. This involved the publication of the Soil Survey Manual in 1937 and an account of the Development and significance of the Great Soil Groups of the United States in 1936; which were subsequently combined in the Yearbook of Agriculture for 1938, Soils and Men in a form more suited to farmers and the general public, where there was a stronger chemical emphasis. In 1949 an evaluation of the whole system was made when consideration was given to the role played by interpretive classifications, as well as of the factors of soil formation. This exercise helped to identify weaknesses in the classification and amendments that were necessary. However, the fundamental conclusion was reached that an entirely new classification system was necessary. 2010-01-27T22:58:45.731Z ]]>