ORCID Profile
0000-0003-3338-2204
Current Organisations
Instituto de Agroquímica y Tecnología de Alimentos
,
University of Western Australia
,
Murdoch University
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Publisher: Elsevier
Date: 1993
Publisher: Elsevier BV
Date: 12-2004
Abstract: Dendritic cells (DCs) consist of a heterogeneous collection of subsets, many with unique phenotypic and functional characteristics. Although certain subsets migrate from peripheral non-lymphoid tissues, there is evidence that antigen presentation can extend to DCs that permanently reside within the lymph node. This Opinion describes this finding in the context of antigen transfer between migrating and lymphoid-resident DCs in cases of T-cell priming and tolerance induction.
Publisher: Elsevier BV
Date: 10-2001
Publisher: Wiley
Date: 20-08-2012
Publisher: Wiley
Date: 09-1983
Publisher: Elsevier BV
Date: 09-2007
Publisher: Wiley
Date: 09-1989
Publisher: Wiley
Date: 1992
Publisher: Springer Science and Business Media LLC
Date: 22-02-2014
Publisher: IEEE
Date: 04-2015
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/EA04186
Abstract: There is considerable interest in integrating deep-rooted perennial plants into the dryland farming systems of southern Australia as soil, water supplies and bio ersity are continually threatened by salinity. In addition to wood products, trees could provide new products, such as bioenergy, environmental services, such as the sequestration of carbon, reductions in recharge to groundwater and bio ersity protection. Before marketing these services, it is necessary to determine the optimal distribution of trees across the landscape, in terms of land suitability, their productivity, and proximity to existing processing and transport infrastructure. Similarly, understanding how recharge varies across landscapes will allow the targeting of trees to areas where they are most needed for salinity control. Catchment scale (1:100 000) soil and landform datasets are now available across much of the agricultural area of Australia. While these data are at a scale inappropriate for management at the enterprise (farm) scale, they will allow broad planning for new plant-based industries, such as whether there is sufficient suitable land available before embarking on a new enterprise and the likely productivity of that land. In this paper, we outline an approach that combines existing soil and landform data with estimates of climate to produce estimates of likely wood yield, carbon sequestration and potential for recharge to groundwater. Using the 283 686 ha Collie catchment of south-western Australia as an ex le, this analysis indicated broad areas where land is suitable for forestry, where forestry is unlikely to succeed, or where it was not required because leakage to groundwater is negligible. It also provides broad estimates of wood production and carbon sequestration. The approach is applicable to the integration of deep-rooted perennial plants into farming systems in other regions confronted with multiple natural resource management issues.
Publisher: MDPI AG
Date: 25-08-2014
DOI: 10.3390/W6092539
Publisher: Wiley
Date: 05-1996
Publisher: Informa UK Limited
Date: 11-06-2018
Publisher: Elsevier BV
Date: 12-1992
Publisher: Elsevier BV
Date: 06-2002
Publisher: Wiley
Date: 09-2010
DOI: 10.1890/08-1935.1
Abstract: Clearing vegetation for traditional agriculture diminishes native habitat and reduces plant transpiration, leading to increased groundwater recharge and onset of dryland salinization due to rising groundwater and mobilization of salt stores in the soil profile. This change in hydrology and salinity can also negatively affect bio ersity in many semiarid regions. Alternating native perennial tree belts with mono-species agriculture within the tree belt alleys is one possible system that can provide recharge control and recover some of the ecosystem services of degraded agricultural landscapes. To assess the effect of this agroforestry technique on groundwater levels, an alley farming trial was established in 1995, incorporating different combinations of belt width, alley width, and revegetation density. Transects of piezometers within each design have been monitored from October 1995 to January 2008. The data set consisted of 70 piezometers monitored on 39 dates. Two trends were observed within the raw data: An increase in water table depth with time and an increase in the range of depths monitored at the site were clearly discernible. However, simple hydrograph analysis of the data has proved unsuccessful at distinguishing the effect of the tree belts on the water table morphology. The statistical techniques employed in this paper to show the effect of the experiment on the water table were variation partitioning, principal coordinates of neighbor matrices (PCNM), and canonical redundancy analysis (RDA). The environmental variables (alley farming design, distance of piezometer from the tree belt, and percentage vegetation cover including edge effect) explained 20-30% of the variation of the transformed and detrended data for the entire site. The spatial PCNM variables explained a further 20-30% of the variation. Partitioning of the site into a northern and southern block increased the proportion of explained variation for the plots in the northern block. The spatial PCNM variables and vegetation cover remained the most significant variables. The PCNM analysis revealed no spatial pattern that could be attributed to the trial. The high proportion of unexplained variation may be due to site variables that have not been considered in this study.
Publisher: Elsevier BV
Date: 03-2013
Publisher: American Geophysical Union (AGU)
Date: 10-1995
DOI: 10.1029/95WR01722
Publisher: Elsevier BV
Date: 09-1990
Publisher: MDPI AG
Date: 09-07-2022
DOI: 10.3390/GELS8070430
Abstract: Besides shear viscosity, other texture parameters (adhesiveness or cohesiveness) might be relevant for safe swallowing in people suffering from oropharyngeal dysphagia. Shear viscosity is assessed through protocols developed using a viscometer or a rheometer. In contrast, protocols and instruments (capillary break-up rheometer) to assess adhesiveness and cohesiveness are less common and much less developed. Other equipment such as texture analyzers can provide useful information on food properties. Here, we aimed to explore different texture analyzer settings (type of test, probe, and protocol) to characterize four commercial dysphagia thickeners at the shear viscosity levels recommended by manufacturers. Among the tests used (extrusion or penetration) with the different probes (disc, cone and shape holder, sphere, or cylinder), cone extrusion provided information about adhesivity, disc extrusion about s le cohesiveness, and sphere about penetration and s le elasticity. The test speeds used influenced the results, but only one speed is needed as the different speeds provided the same fluid information for easiness, it is proposed to use 1 mm/s. Comparing the texture analyzer results with viscosity values obtained at different shears, the texture analyzer parameters reflected information that differ from shear viscosity. This information could be relevant for the therapeutic effect of thickening products and food characterization.
Publisher: CSIRO Publishing
Date: 1991
DOI: 10.1071/SR9910587
Abstract: The accurate characterization of soil water and air properties is difficult in soil survey because of logistic constraints. Less reliable surrogates are commonly used to estimate these properties. The surrogates provide a method for moving from measures that tend to be static and semi-empirical to those characterizing soil processes. The utility of four schemes for predicting air-filled porosity, available water capacity and saturated hydraulic conductivity on the basis of field-determined soil morphology has been assessed using data from a limited number of profiles with features commonly encountered in Australia. None of the systems provided statistically significant predictions of available water capacity and the results for air-filled porosity were moderate (McKeague et al. (1986), r2 = 0.58 Hall et al. (19771, r2 = 0 -64 Williams et al. (1991), r2 = 0.70). Encouragingly, the Hollis and Woods (1989) system generated good predictions of field-saturated hydraulic conductivity (r2 = 0.77). It is concluded that better measurement methods and programs of data collection are needed for both the properties used as surrogates (e.g. morphology) and those for which predictions are required (e.g. air and water properties).
Publisher: Elsevier
Date: 2004
Publisher: Elsevier BV
Date: 07-1985
Publisher: CSIRO Publishing
Date: 1995
DOI: 10.1071/EA9951058
Abstract: No abstract available.
Publisher: JSTOR
Date: 12-1993
DOI: 10.2307/2532267
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2016
Publisher: Elsevier BV
Date: 10-2018
Publisher: Elsevier BV
Date: 08-2009
Publisher: Copernicus GmbH
Date: 18-12-2018
Abstract: Abstract. Editors of several journals in the field of hydrology met during the General Assembly of the European Geosciences Union (EGU) in Vienna in April 2017. This event was a follow-up of similar meetings held in 2013 and 2015. These meetings enable the group of editors to review the current status of the journals and the publication process, and to share thoughts on future strategies. Journals were represented at the 2017 meeting by their editors, as shown in the list of authors. The main points on invigorating hydrological research through journal publications are communicated in this joint editorial published in the above journals.
Publisher: Wiley
Date: 18-11-2011
Publisher: Wiley
Date: 2005
DOI: 10.1002/HYP.5679
Publisher: Elsevier BV
Date: 04-2007
Publisher: Elsevier BV
Date: 03-2017
Publisher: Wiley
Date: 26-05-2010
DOI: 10.1002/ECO.131
Publisher: Copernicus GmbH
Date: 10-05-2006
Abstract: Abstract. A simple conceptual water balance model representing the streamflow generation processes on a daily time step following land use change is presented. The model consists of five stores: (i) Dry, Wet and Subsurface Stores for vertical and lateral water flow, (ii) a transient Stream zone Store (iii) a saturated Goundwater Store. The soil moisture balance in the top soil Dry and Wet Stores are the most important components of the model and characterize the dynamically varying saturated areas responsible for surface runoff, interflow and deep percolation. The Subsurface Store describes the unsaturated soil moisture balance, extraction of percolated water by vegetation and groundwater recharge. The Groundwater Store controls the baseflow to stream (if any) and the groundwater contribution to the stream zone saturated areas. The daily model was developed following a downward approach by analysing data from Ernies (control) and Lemon (53% cleared) catchments in Western Australia and elaborating a monthly model. The daily model performed very well in simulating daily flow generation processes for both catchments. Most of the model parameters were incorporated a priori from catchment attributes such as surface slope, soil depth, porosity, stream length and initial groundwater depth, and some were calibrated by matching the observed and predicted hydrographs. The predicted groundwater depth, and streamflow volumes across all time steps from daily to monthly to annual were in close agreement with observations for both catchments.
Publisher: Walter de Gruyter GmbH
Date: 14-08-2018
Abstract: Editors of several journals in the field of hydrology met during the General Assembly of the European Geosciences Union-EGU in Vienna in April 2017. This event was a follow-up of similar meetings held in 2013 and 2015. These meetings enable the group of editors to review the current status of the journals and the publication process, and to share thoughts on future strategies. Journals were represented at the 2017 meeting by their editors, as shown in the list of authors. The main points on invigorating hydrological research through journal publications are communicated in this joint editorial published in the above journals.
Publisher: CSIRO Publishing
Date: 1987
DOI: 10.1071/AR9870829
Abstract: The effects of two rotation and two tillage systems on earthworm populations have been studied in a red-brown earth under wheat. At the time of s ling, the earthworm population under direct drill was nearly double that under conventional cultivation. The total number of worms was not affected by crop rotation with pasture or lupins, but following pasture there were significantly more large worms. It is suggested that at this site the earthworm population may be responding rapidly to alterations in food supply and water stress under the different agricultural systems.
Publisher: CSIRO Publishing
Date: 1999
DOI: 10.1071/A97074
Abstract: A physico-empirical 2-parameter power law model of the draining water retention curve (WRC) based solely on clay content is described and further developed using 6 datasets obtained from Australian and New Zealand soils. The slope of the WRC, or pore-size distribution index, is well described by the model but the bubbling pressure, or inflection point is poorly described. Without a good estimation of the bubbling pressure it is not possible to scale the physico-empirical model to the WRC. To achieve the scaling, a single measured point on the WRC in the unsaturated range is required. The resulting estimated water contents may be satisfactory for application within broad-scale leaching risk models and for generalised extrapolation of results from detailed experimental sites but caution is still required for quantitative applications of nitrate leaching models at a particular site. It is concluded that soil surveys could usefully include a single WRC measurement in the field at each s ling location to improve their utility for water and chemical transport modelling.
Publisher: Springer Science and Business Media LLC
Date: 12-03-2009
Publisher: Wiley
Date: 14-05-2013
DOI: 10.1111/GCB.12223
Abstract: There is increasing concern that widespread forest decline could occur in regions of the world where droughts are predicted to increase in frequency and severity as a result of climate change. The average annual leaf area index (LAI) is an indicator of canopy cover and the difference between the annual maximum and minimum LAI is an indicator of annual leaf turnover. In this study, we analyzed satellite-derived estimates of monthly LAI across forested coastal catchments of southwest Western Australia over a 12 year period (2000-2011) that included the driest year on record for the last 60 years. We observed that over the 12 year study period, the spatial pattern of average annual satellite-derived LAI values was linearly related to mean annual rainfall. However, interannual changes to LAI in response to changes in annual rainfall were far less than expected from the long-term LAI-rainfall trend. This buffered response was investigated using a physiological growth model and attributed to availability of deep soil moisture and/or groundwater storage. The maintenance of high LAIs may be linked to a long-term decline in areal average underground water storage and diminished summer flows, with an emerging trend toward more ephemeral flow regimes.
Publisher: CSIRO Publishing
Date: 2004
DOI: 10.1071/EA02093
Abstract: Rhizoctonia solani Anastomosis Group 8 damages seedling roots of wheat, causing the 'bare-patch' disease. This makes the first 4 weeks after germination the most critical period for disease development. As the field inoculum of the pathogen is mainly concentrated in the surface 10 cm of soil, the rate of root growth becomes critical for the vulnerable tissues of the root to escape the attack from the inoculum zone. To evaluate the effect of alteration of root growth by soil compaction on disease severity, a study was undertaken in 40-cm-deep pots made from PVC pipes (8.7 cm diameter). Four depths of soil compaction (whole soil profile compacted, whole soil loose, upper 10 cm loose and compacted below, upper 20 cm loose and compacted below) were tested using sieved soil. Effective root length of infected seedlings was higher in the pots where the whole soil profile was compacted than others. Reduction in dry root weights, where soil was compacted to heights of 0, 17.5, 27.5 or 37.5 cm following inoculation, were 68, 30, 74 and 56%, respectively. Reduction in shoot weights was 52, 22, 66 and 44%, respectively. Eight days after incubation, microbial activity was greater where the soil was highly compacted than where there was a low level of soil compaction. Saprophytic growth in soil of Rhizoctonia solani Anastomosis Group 8 was higher in loosely packed soil than in compacted soil. This shows that higher impact of disease under compacted soil conditions is due to reduced root growth and that disturbing the soil below seeds can reduce the impact of disease.
Publisher: Springer Science and Business Media LLC
Date: 09-11-2009
Publisher: Informa UK Limited
Date: 06-2002
DOI: 10.1071/EG02095
Publisher: MDPI AG
Date: 19-07-2017
DOI: 10.3390/W9070542
Abstract: Quantifying the travel times, pathways, and dispersion of solutes moving through stream environments is critical for understanding the biogeochemical cycling processes that control ecosystem functioning. Validation of stream solute transport and exchange process models requires data obtained from in-stream measurement of chemical concentration changes through time. This can be expensive and time consuming, leading to a need for cheap distributed sensor arrays that respond instantly and record chemical transport at points of interest on timescales of seconds. To meet this need we apply new, low-cost (in the order of a euro per sensor) potentiometric chloride sensors used in a distributed array to obtain data with high spatial and temporal resolution. The application here is to monitoring in-stream hydrodynamic transport and dispersive mixing of an injected chemical, in this case NaCl. We present data obtained from the distributed sensor array under baseflow conditions for stream reaches in Luxembourg and Western Australia. The reaches were selected to provide a range of increasingly complex in-channel flow patterns. Mid-channel sensor results are comparable to data obtained from more expensive electrical conductivity meters, but simultaneous acquisition of tracer data at several positions across the channel allows far greater spatial resolution of hydrodynamic mixing processes and identification of chemical ‘dead zones’ in the study reaches.
Publisher: Wiley
Date: 10-11-2009
DOI: 10.1002/HYP.7509
Publisher: American Geophysical Union (AGU)
Date: 06-1996
DOI: 10.1029/96WR00677
Publisher: Elsevier BV
Date: 07-1985
Publisher: CSIRO Publishing
Date: 1996
DOI: 10.1071/SR9960695
Abstract: The soil water retention curve (WRC) may be estimated from soil texture if there is shape similarity between the normalised cumulative particle mass size distribution curve (PSD) and the WRC. For similar shaped curves, parameters describing the shape of the PSD may also describe the shape of the corresponding WRC. We studied the relation between PSDs and WRCs at 4 sites in Western Australia with predominantly sandy soils and fitted a sigmoidal function to all normalised PSDs and WRCs. The model gave an excellent description of all PSD and WRC data sets. The parameter describing the slope of the WRC was correlated with the slope of the PSD. However, the asymptotic minima of the PSDs differed from the WRCs leading to poor estimates of the WRC residual water contents, θr. This difference was most marked in 2 clay subsoils and resulted in progressively greater errors in prediction of water content with increasing negative pressure head.
Publisher: Elsevier BV
Date: 04-1993
Publisher: Elsevier BV
Date: 12-2018
DOI: 10.1016/J.JENVMAN.2018.09.048
Abstract: A laboratory-scale vertical flow constructed wetland system was designed and monitored to compare nitrogen removal rates and pathways from both saturated and unsaturated zones under a hydraulic loading rate and influent total nitrogen concentration of 1.5 m
Publisher: Elsevier BV
Date: 04-1983
Publisher: Copernicus GmbH
Date: 23-03-2020
DOI: 10.5194/EGUSPHERE-EGU2020-3214
Abstract: & & Understanding how summer low flows in a Mediterranean climate are in& #64258 uenced by climate and land use is critical for managing both water resources and in-stream ecohydrological health. The Eucalyptus forest ecosystems of southwestern Australia are experiencing a drying and warming climate, with a regional step decline in rainfall in the mid-1970s. & Reductions in catchment water storage may be exacerbated by the deep rooting habit of key overstorey species (& m has been reported), which can buffer against drought during dry years. Root exploitation of deep soil moisture reserves and/or groundwater can accelerate the long term decline in summer low & #64258 ows, with a trend towards more ephemeral & #64258 ow regimes. In contrast, conversion of forests to agricultural land in some catchments can lead to counter-trends of increased low flows due to a rise in groundwater pressure.& These are invariably associated with an increase in stream salinity as regolith stores of salt are mobilized. There has also been extennsive reforestation of farmland in some catchments.& & & & & In this study we perform a detailed analysis of changes to annual summer seven day low flow trends in perennial catchments and flow duration curves in ephemeral catchments across 39 catchments in south-western Australia that have long term records of runoff, rainfall and land cover.& Results showed that 15% of catchments exhibited increased low flows and 85% decreased flows or decreased flow days since the 1970s.& Significant downward step changes in low flows were observed in 17 catchments (44%). The earliest downward step changes occurred in three catchments between 1981-82 (a lag of one decade after the rainfall decline), with the most recent step changes for five catchments occurring in 2001-2004 (three decades after rainfall decline). & Eleven catchments were already ephemeral in the 1970s, but exhibited continued declines in the number of annual flow days over subsequent decades.& Step changes occur when groundwater becomes disconnected or reconnected to the stream invert, with disconnection associated with rainfall decline and vegetative water use.& & & & & & The statistical methods we used in this study can be applied to any catchment in order to aid land and water managers assess the impact of climate change and land cover manipulation on low flow response.& &
Publisher: Elsevier BV
Date: 10-1985
Publisher: Elsevier BV
Date: 02-2007
Publisher: Wiley
Date: 09-2009
DOI: 10.1002/ECO.84
Publisher: Copernicus GmbH
Date: 11-07-2006
Abstract: Abstract. We developed a coupled salt and water balance model to represent the stream salinity generation process following land use changes. The conceptual model consists of three main components with five stores: (i) Dry, Wet and Subsurface Stores, (ii) a saturated Groundwater Store and (iii) a transient Stream zone Store. The Dry and Wet Stores represent the salt and water movement in the unsaturated zone and also the near-stream dynamic saturated areas, responsible for the generation of salt flux associated with surface runoff and interflow. The unsaturated Subsurface Store represents the salt bulge and the salt fluxes. The Groundwater Store comes into play when the groundwater level is at or above the stream invert and quantifies the salt fluxes to the Stream zone Store. In the stream zone module, we consider a "free mixing" between the salt brought about by surface runoff, interflow and groundwater flow. Salt accumulation on the surface due to evaporation and its flushing by initial winter flow is also incorporated in the Stream zone Store. The salt balance model was calibrated sequentially following successful application of the water balance model. Initial salt stores were estimated from measured salt profile data. We incorporated two lumped parameters to represent the complex chemical processes like diffusion-dilution-dispersion and salt fluxes due to preferential flow. The model has performed very well in simulating stream salinity generation processes observed at Ernies and Lemon experimental catchments in south west of Western Australia. The simulated and observed stream salinity and salt loads compare very well throughout the study period with NSE of 0.7 and 0.4 for Ernies and Lemon catchment respectively. The model slightly over predicted annual stream salt load by 6.2% and 6.8%.
Publisher: Springer Science and Business Media LLC
Date: 30-08-2006
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/J.JENVMAN.2013.08.020
Abstract: A dynamic model of Phosphorus (P) movement through the Peel-Harvey catchment in South Western Australia was developed using system dynamics modelling software. The model was developed to illustrate watershed P flux and to predict future P loss rates under a range of management scenarios. Model input parameters were sourced from extensive surveys of local agricultural practices and regional soil testing data. Model P-routing routines were developed from the known interactions between the various watershed P compartments and fluxes between the various P stores. Phosphorus-retention characteristics of a variety of management practices were determined from local field trials where available and published values where not. The model simulated a 200 year time frame to reflect 100 years to the present day since initial land development, and forecast 100 years into the future. Although the catchment has an annual P-loss target of 70 tonnes per annum (tpa), the measured (and modelled) present-day loss is double this amount (140 tpa) and this is projected to rise to 1300 tpa if current land management practices continue. Broad implementation of neither "biological" BMPs such as perennial pastures and managed riparian zones, or of "chemical" BMPs such as reduced water solubility fertilisers and P-retentive soil amendments, produces reductions in P-loss from present-day levels. Even if broad-scale implementation of the large suite of BMPs tested in this research occurs, catchment P-losses are likely to increase from the present level of 140 tpa to approximately 200 tpa over the next 100 years. This has significant implications for both future land use and subsequent water quality in the catchment as well as questioning the wisdom and perceptions of efficacy of past and future BMP implementation strategies.
Publisher: Copernicus GmbH
Date: 05-11-2009
DOI: 10.5194/HESS-13-2095-2009
Abstract: Abstract. Widespread clearing of native vegetation in Southwest Western Australia has led to land degradation associated with rising groundwater, secondary salinisation and waterlogging. Re-establishing deep-rooted perennial vegetation across parts of the landscape is one technique for managing land degradation. Alley farming is an agroforestry practice where multiple perennial tree belts are planted in alternation with traditional agricultural crops. To identify the best configuration (belt width versus alley width) for controlling rising groundwater levels and providing viable economic returns, a large scale experiment was established in 1995. The experiment contains seven different alley farming designs, each with transects of piezometers running across tree belts into adjacent alleys to monitor changes in the groundwater level. Two control piezometers were also installed in an adjacent paddock. Groundwater at the site is shallow ( m) and of poor quality (pH 3–5, Ec 2.1–45.9 mS cm−1) so root water uptake from the saturated zone is limited. Simple hydrograph analysis could not separate treatment effects on the water table response. Subsequent statistical analysis revealed that 20–30% of the variability in the water table data over the 12 year study period was attributable to the alley farming experiment. To futher investigate the effect of the experiment on groundwater response, additional hydrograph analysis was conducted to compare the trends in the control piezometers in relation to those located within the belts. A difference of 0.9 m was observed between the mean groundwater levels in the control piezometers and the mean levels in the perennial belt piezometers. For a mean specific yield of 0.03 m3 m−3 (standard deviation of 0.03 m3 m−3) this equates to an additional average annual water use of 27 mm yr−1 (standard deviation of 33 mm yr−1) by the perennial agroforestry system. It is concluded that declining annual rainfall is the principal control on hydrograph response at the site, whilst perennial biomass development has a lesser impact on water table depth.
Publisher: Elsevier BV
Date: 2011
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/SR03146
Abstract: Water balance modelling based on Richards’ equation requires accurate description of the soils’ hydraulic parameters. Unfortunately, these parameters vary spatially and temporally as well as between measurement techniques. For most field modelling exercises, the hydraulic parameters are obtained from a small number of measurements or predicted from soil properties using pedo-transfer functions. The effect of different measurement techniques on the description of soil hydraulic parameters has been the subject of many studies but the effect of the variability of the hydraulic parameters on the predicted water balance has not been widely investigated. In this study we compared the hydraulic parameters obtained solely from laboratory measurements with those obtained from a rapid wet end field measurement technique, augmented by dry end laboratory data. The water balance was modelled using the laboratory and field hydraulic parameter sets and compared to field water contents measured by time domain reflectometry (TDR). In a sandy soil, we found the total profile water content to be well modelled by both hydraulic parameter datasets, but the water content at a specific depth was less well predicted using either of the measured parameter sets. The water content at a specific depth was under-predicted prior to the rainfall event and over-predicted after the rainfall, regardless of whether the hydraulic parameters were obtained from laboratory or field measurements. Generally, the hydraulic parameters that were obtained from the field measurements gave a closer fit to the measured TDR water contents. The sensitivity of the modelled water balance to changes in the hydraulic parameters within the observed range of parameter values was also investigated. Parameter percentage coefficient of variation within measurement techniques ranged from 60% for air entry, he 19% for residual water content, θr 5% for slope of the water retention curve, n and 7% for saturated water content, θs. The percentage differences between the parameters obtained from the laboratory and field measurement techniques for the topsoil and subsoil respectively were 47% and 50% for he, 100% for θr, 28% and 40% for n, and –14.4% and 4.0% for θs. Modelling water content changes at a particular depth in the sandy soil was found to be most influenced by variations in θs, and n. Predicted water contents were also affected by the θr but less influenced by the saturated hydraulic conductivity, Ks. The he was the least influential parameter but also the most variable. This suggests that measurement of θs, related to bulk density changes caused by tillage, wheel compaction, and consolidation, is required for water balance studies. Generally, n had small variability between measurements at a particular depth, which is promising for the use of pedo-transfer functions related to soil texture.
Publisher: American Chemical Society (ACS)
Date: 21-01-2010
DOI: 10.1021/EF9005687
Publisher: CSIRO Publishing
Date: 1994
DOI: 10.1071/SR9941175
Abstract: Experiments to characterize runoff and drainage from large undisturbed soil cores obtained from a site under volunteer pasture are presented. The objectives were to evaluate if a simple kinematic wave model could be used to characterize drainage under conditions of by-passing flow and to investigate the variability of runoff generation under wet and dry antecedent conditions in this well structured soil. Cores were taken to depths of 0.4 and 0.7 m, with six cores obtained from each depth. Results show that variations in soil structure between cores have a greater influence on the hydrologic response than variations in antecedent water content. It may be inferred that, in this soil, good structural continuity substantially enhances soil drainage and, in consequence, decreases surface runoff. During wetting, kinematic celerities ranged from 337 to 3200 mm h-1 in the short cores and from 357 to 1400 mm h-1 in the long cores. The corresponding estimated ranges of mobile or 'macropore' fractions were from 0.015 to 0.154 m3 m-3 in the short cores and 0.033 to 0.132 m3m-3 in the long cores. Both parameters were approximately log-normally distributed. Measured drainage hydrographs were reasonably well described by the kinematic model but the physical significance of the model parameters was unclear.
Publisher: American Geophysical Union (AGU)
Date: 11-1994
DOI: 10.1029/94WR01787
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/SR02052
Abstract: Immobile water fractions of up to 40% had been reported in sands, and it was therefore relevant to determine if the convection-dispersion equation (CDE) or mobile-immobile model (MIM) should be used as the basic physical model for field studies of solute transport in sandy soils. A review of literature data for granular media indicated that for steady state flow, the dispersion coefficient could be estimated from the grain Peclét number and the mass exchange coefficient from the pore water velocity, but the immobile water fraction was poorly predicted from soil properties.In this study, performed on a sandy soil at Moora, Western Australia, the choice of model was determined after analysis of column effluent breakthrough curves (BTC), sequential tracer experiments, and single tracer experiments on the same core. The latter two methods have recently been introduced in an attempt to independently measure some of the MIM parameters (immobile water content and mass transfer exchange coefficient) in situ. Low immobile water content was found in this sand, with very rapid exchange between the mobile and immobile regions. All 3 techniques gave measured immobile water contents around 10%, which was consistent with most literature values for granular media. The single tracer experiment does not give the mass exchange coefficient α (h–1), but α determined by the sequential tracer technique could not be confirmed by the BTC technique due to the wide 95% confidence interval of the fitted parameter. Although the MIM behaviour was minor and inconsistent in the Moora sand, the choice of model may depend on the problem under consideration. For short column experiments, the CDE and MIM produced similar solute transport behaviour. However, for leaching below the root-zone, the MIM is recommended.
Publisher: Elsevier BV
Date: 05-2019
Publisher: American Geophysical Union (AGU)
Date: 11-1994
DOI: 10.1029/94WR01788
Publisher: Elsevier BV
Date: 06-1993
Publisher: Elsevier BV
Date: 06-2000
Publisher: Springer Science and Business Media LLC
Date: 15-07-2006
Publisher: American Geophysical Union (AGU)
Date: 06-2020
DOI: 10.1029/2018WR024053
Publisher: Springer Science and Business Media LLC
Date: 2001
Publisher: Elsevier BV
Date: 1992
Publisher: Wiley
Date: 2018
DOI: 10.2136/VZJ2018.06.0001ED
Abstract: Editors of several journals in the field of hydrology met during the General Assembly of the European Geosciences Union (EGU) in Vienna in April 2017. This event was a follow‐up of similar meetings held in 2013 and 2015. These meetings enable the group of editors to review the current status of the journals and the publication process, and to share thoughts on future strategies. Journals were represented at the 2017 meeting by their editors, as shown in the list of authors. The main points on invigorating hydrological research through journal publications are communicated in this joint editorial published in our journals.
Publisher: Elsevier BV
Date: 12-2018
Publisher: Wiley
Date: 11-2016
DOI: 10.1111/EJSS.12390
Publisher: Springer Science and Business Media LLC
Date: 19-10-2015
Publisher: Elsevier BV
Date: 1991
Publisher: Springer Science and Business Media LLC
Date: 04-2006
Publisher: American Geophysical Union (AGU)
Date: 07-2021
DOI: 10.1029/2021WR029638
Abstract: Understanding daytime ( ET D ) and nighttime ( ET N ) evapotranspiration is critical for accurately evaluating terrestrial water and carbon cycles. However, unlike ET D , the factors influencing ET N remain poorly understood. Here, long‐term ET D and ET N data from five FLUXNET sites along a climate gradient in Northern Australia were analyzed to compare their responses to environmental drivers at different temporal scales. We found that (a) across the sites, mean annual ET N / ET D ( / ) ranged between 5.1% and 11.7%, which was mainly determined by variations. Particularly, vegetation and meteorological variables mostly controlled , while was largely related to air temperature and net radiation ( Rn ) due to lower nighttime atmospheric water demands (b) At in idual sites, ET D and ET N exhibited higher correlations with meteorological and vegetation variables at monthly timescales than at annual timescales. Monthly ET D and ET N were also strongly coupled, especially under drier climatic conditions. At daily timescales, leaf area index and soil water content (SWC) controlled ET D with SWC being more important at drier sites whereas, SWC was the dominant factor controlling ET N . At half‐hourly timescales, the boosted regression tree method quantitively showed that ET D and ET N were controlled by Rn and SWC, respectively. Overall, the results showed that ET N was less responsive to environmental variables, illustrating that ET D and ET N responded differently to erse climate regimes and ecosystems at varying temporal scales. These findings provide a critical evaluation for contrasting ET D and ET N interactions in constantly changing environments, which has important implications for ecosystem water balance and land surface processes modeling.
Publisher: Elsevier BV
Date: 1984
Publisher: American Meteorological Society
Date: 31-10-2018
Publisher: Elsevier BV
Date: 1983
Publisher: Wiley
Date: 09-1986
Publisher: Wiley
Date: 1993
Publisher: Springer Science and Business Media LLC
Date: 09-05-2009
Publisher: Elsevier BV
Date: 10-2018
Publisher: CSIRO Publishing
Date: 1999
DOI: 10.1071/AR97075
Abstract: Regional scale application of water and solute transport models is often limited by the lack of available data describing soil hydraulic properties and their variability. Direct measurement over large areas is expensive and time consuming. Physico-empirical models derived from soil survey data are therefore an attractive alternative. If the Marshall method of estimating the saturated hydraulic conductivity is simplified to depend primarily on the maximum pore radius, given by the bubbling pressure, then it is equivalent to the C bell model of saturated hydraulic conductivity which relies entirely on an estimate of the bubbling pressure obtained from particle size data. We apply this simplified physico-empirical model to estimate the ‘matrix’, or textural saturated hydraulic conductivity, K m, using estimates of the bubbling pressure derived entirely from clay content data that are readily available in soil surveys. Model estimates are compared with in situ measurements on surface soils obtained using a disc permeameter with a negative pressure head at the supply surface of 40 mm. Results appear to be satisfactory for broad-scale water balance and leaching risk models that require specification of a matching point for the unsaturated hydraulic conductivity function and for modelling applications requiring generalised application of results from experimental sites.
Publisher: Copernicus GmbH
Date: 10-01-2014
DOI: 10.5194/HESSD-11-307-2014
Abstract: Abstract. Application of the conventional chloride mass balance (CMB) method to point recharge dominant groundwater basins can substantially under-estimate long-term average annual recharge by not accounting for the effects of localized surface water inputs. This is because the conventional CMB method ignores the duality of infiltration and recharge found in karstic systems, where point recharge can be a contributing factor. When point recharge is present in groundwater basins, recharge estimation is unsuccessful using the conventional CMB method with, either unsaturated zone chloride or groundwater chloride. In this paper we describe a generalized CMB that can be applied to groundwater basins with point recharge. Results from this generalized CMB are shown to be comparable with long-term recharge estimates obtained using the watertable fluctuation method, groundwater flow modelling and Darcy flow calculations. The generalized CMB method provides an alternative, reliable long-term recharge estimation method for groundwater basins characterised by both point and diffuse recharge.
Publisher: Wiley
Date: 12-08-2018
DOI: 10.1002/ECO.2016
Publisher: Wiley
Date: 03-1983
Publisher: Springer Science and Business Media LLC
Date: 2000
Publisher: Copernicus GmbH
Date: 06-09-2013
DOI: 10.5194/HESSD-10-11423-2013
Abstract: Abstract. Karstic limestone aquifers are hydrologically and hydrochemically extremely heterogeneous and point source recharge via sinkholes and fissures is a common feature. We studied three groundwater systems in karstic settings dominated by point source recharge in order to assess the relative contributions to total recharge from point sources using chloride and δ18O relations. Preferential groundwater flows were observed through an inter-connected network of highly conductive zones with groundwater mixing along flow paths. Measurements of salinity and chloride indicated that fresh water pockets exist at point recharge locations. A measurable fresh water plume develops only when a large quantity of surface water enters the aquifer as a point recharge source. The difference in chloride concentrations in diffuse and point recharge zones decreases as aquifer saturated thickness increases and the plumes become diluted through mixing. The chloride concentration in point recharge fluxes crossing the watertable plane can remain at or near surface runoff chloride concentrations, rather than in equilibrium with groundwater chloride. In such circumstances the conventional chloride mass balance method that assumes equilibrium of recharge water chloride with groundwater requires modification to include both point and diffuse recharge mechanisms.
Publisher: MDPI AG
Date: 19-05-2017
DOI: 10.3390/W9050358
Publisher: Wiley
Date: 12-2013
DOI: 10.1002/ECO.1441
Publisher: Wiley
Date: 29-08-2014
DOI: 10.1111/GCBB.12090
Publisher: IWA Publishing
Date: 29-08-2018
DOI: 10.2166/NH.2018.124
Abstract: Editors of several journals in the field of hydrology met during the General Assembly of the European Geosciences Union – EGU in Vienna in April 2017. This event was a follow-up of similar meetings held in 2013 and 2015. These meetings enable the group of editors to review the current status of the journals and the publication process, and to share thoughts on future strategies. Journals were represented at the 2017 meeting by their editors, as shown in the list of authors. The main points on invigorating hydrological research through journal publications are communicated in this joint editorial published in the journals listed here.
Publisher: Wiley
Date: 03-2015
Publisher: Elsevier BV
Date: 08-2001
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-1987
Publisher: Elsevier BV
Date: 2012
Publisher: Wiley
Date: 03-1990
Publisher: Copernicus GmbH
Date: 05-11-2018
DOI: 10.5194/HESS-22-5735-2018
Abstract: Abstract. Editors of several journals in the field of hydrology met during the General Assembly of the European Geosciences Union (EGU) in Vienna in April 2017. This event was a follow-up of similar meetings held in 2013 and 2015. These meetings enable the group of editors to review the current status of the journals and the publication process, and to share thoughts on future strategies. Journals were represented at the 2017 meeting by their editors, as shown in the list of authors. The main points on invigorating hydrological research through journal publications are communicated in this joint editorial published in the above journals.
Location: United Kingdom of Great Britain and Northern Ireland
Location: Spain
No related grants have been discovered for Amparo Tarrega.