The requirements of ecological studies and water resource management plans are driving demand for hydrological models of the rivers of the arid zone. Knowledge of the hydrology of Australia’s arid zone is poor, yet is critical in understanding the ecology of the region. The research presented in this thesis seeks to address some shortcomings in our understanding of the hydrology of the Australian arid zone. In particular, the research examines the requirements for modelling the flow regime of arid zone rivers, concentrating on the rivers of the Lake Eyre Basin (LEB). The LEB has exceptionally low annual runoff of 3.5 mm, its major rivers develop over extremely low gradients and are characterised by very wide floodplains and complex anastomosing flow paths in their mid to lower reaches. This research was driven by both a practical and theoretical impetus. Practically, hydrological data were required at the water body scale for a large number of sites across three river systems of the LEB, for use in a study, known as ARIDFLO, of the ecological responses to hydrological conditions. Because of the remoteness of these sites and the paucity of gauging stations on these rivers, modelling of the rivers was the only method for delivering the required discharge data. Theoretically, the challenge was set for creating hydrological models for some extraordinarily complex river systems, in terms of their size, catchment characteristics and flow regime variability. (For complete abstract open document)

Reservoir quality of subsurface sandstones depends on the composition, texture and grain size of the initial sediments. These factors are a function of hinterland processes: tectonic setting, provenance, climate and depositional environment, and sediment transportation processes. This study focuses on a modern, dryland, fluvial deposition system from source-to-sink that aims to provide a quantitative dataset analogue to facilitate forward modelling for prediction of subsurface compositions, grain size and textures of reservoir sandstones. Umbum Creek, in the western Lake Eyre Basin of Central Australia, was selected as a small river network (~ 100km²) in order to study source-to-sink sedimentation. The provenance area was analysed using isopach maps derived from a 783 drill-hole dataset, which included stratigraphy and lithology information. Subsequently forty-three samples of different provenance lithotypes from the Umbum Creek catchment were collected for petrographic thin-section analysis. Recent sediments were then sampled from 90 strategically located stream confluences along Umbum Creek and tributaries (proximal, medial and distal subsets). A quantitative textural and compositional dataset was subsequently generated from 34 selected samples. With half-phi sieve analysis (4mm to 32 microns), and an associated petrographic description recognising 72 categories of grain composition was undertaken for each sample. The provenance analysis using isopach maps demonstrated that Palaeozoic and Mesozoic sedimentary basin evolution in the study area was controlled by northeast and northwest-trending structural elements. The regional uplift of the Peake and Denison Inliers that occurred during the Cenozoic had a significant impact on the evolution of the Lake Eyre Basin, causing changes in the provenance of Late Neogene sedimentation and on through to the present. The sink area represents a shallow intracratonic basin whereby a thin veneer of fluvial/lacustrine sediments is accumulating adjacent to a basement uplift. This study has highlighted the importance of multiple sediment provenances. Five different provenance lithotype grains were identified in the Umbum Creek modern sediments: the Gawler Craton plutonic / basement provenance (recycled) the Peake and Denison Inliers Proterozoic volcanic provenance (recycled), the Davenport Ranges metamorphic provenance, the Mesozoic sedimentary provenance and the Cenozoic sedimentary provenance. Whereas a downstream fining of grain size was expected, a general trend of downstream coarsening of grain size was noted being the result of aeolian deflation of fines and intra-basinal coarse-grained sediment contributions. In the sink area, modern sediments from the terminal splay complex comprise 70-80% quartz, 10-20% lithic fragments (of which ~ 7% are ductile lithic grains), < 3% feldspar, and clay (<2%). Grains are sub-angular to well-rounded and moderately well sorted. The compositional and textural maturity of the terminal splay sediments is attributed to reworked plutonic quartz grains, the dissolution and disintegration of feldspar and carbonate grains during transportation, along with the breakdown of lithic fragments due to fluvio-aeolian interactions and subsequent mechanical/ chemical weathering processes. These data were used to build a predictive forward model for modal sandstone analysis that achieved a fair to good correlation between predicted and observed grain lithotypes and provenance categories. These results illustrate that the character of sands in the Umbum Creek catchment are governed by a multiplicity of controls such as tectonic setting, provenance lithotype analysis, climate, regional topographic gradient, hinterland transport distance, basin subsidence rate and depositional environment. The fluvio-aeolian depositional environment along with the current arid to semi-arid playa climatic conditions of Umbum Creek catchment facilitate the growth of clay coatings, however accounts for a low clay matrix within the deposits. In addition, the playa environment also facilitates the alteration of infiltrated detrital clay to kaolinite, the formation of evaporites (gypsum, halite and anhydrite) and the formation of authigenic clays. These factors are all significant in determining the ultimate reservoir quality of reservoir sandstones, emphasising the importance of this study as an analogue for modelling ‘buried’ dryland depositional systems. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1337211 / Thesis (Ph.D.) -- University of Adelaide, Australian School of Petroleum, 2008

Reservoir quality of subsurface sandstones depends on the composition, texture and grain size of the initial sediments. These factors are a function of hinterland processes: tectonic setting, provenance, climate and depositional environment, and sediment transportation processes. This study focuses on a modern, dryland, fluvial deposition system from source-to-sink that aims to provide a quantitative dataset analogue to facilitate forward modelling for prediction of subsurface compositions, grain size and textures of reservoir sandstones. Umbum Creek, in the western Lake Eyre Basin of Central Australia, was selected as a small river network (~ 100km²) in order to study source-to-sink sedimentation. The provenance area was analysed using isopach maps derived from a 783 drill-hole dataset, which included stratigraphy and lithology information. Subsequently forty-three samples of different provenance lithotypes from the Umbum Creek catchment were collected for petrographic thin-section analysis. Recent sediments were then sampled from 90 strategically located stream confluences along Umbum Creek and tributaries (proximal, medial and distal subsets). A quantitative textural and compositional dataset was subsequently generated from 34 selected samples. With half-phi sieve analysis (4mm to 32 microns), and an associated petrographic description recognising 72 categories of grain composition was undertaken for each sample. The provenance analysis using isopach maps demonstrated that Palaeozoic and Mesozoic sedimentary basin evolution in the study area was controlled by northeast and northwest-trending structural elements. The regional uplift of the Peake and Denison Inliers that occurred during the Cenozoic had a significant impact on the evolution of the Lake Eyre Basin, causing changes in the provenance of Late Neogene sedimentation and on through to the present. The sink area represents a shallow intracratonic basin whereby a thin veneer of fluvial/lacustrine sediments is accumulating adjacent to a basement uplift. This study has highlighted the importance of multiple sediment provenances. Five different provenance lithotype grains were identified in the Umbum Creek modern sediments: the Gawler Craton plutonic / basement provenance (recycled) the Peake and Denison Inliers Proterozoic volcanic provenance (recycled), the Davenport Ranges metamorphic provenance, the Mesozoic sedimentary provenance and the Cenozoic sedimentary provenance. Whereas a downstream fining of grain size was expected, a general trend of downstream coarsening of grain size was noted being the result of aeolian deflation of fines and intra-basinal coarse-grained sediment contributions. In the sink area, modern sediments from the terminal splay complex comprise 70-80% quartz, 10-20% lithic fragments (of which ~ 7% are ductile lithic grains), < 3% feldspar, and clay (<2%). Grains are sub-angular to well-rounded and moderately well sorted. The compositional and textural maturity of the terminal splay sediments is attributed to reworked plutonic quartz grains, the dissolution and disintegration of feldspar and carbonate grains during transportation, along with the breakdown of lithic fragments due to fluvio-aeolian interactions and subsequent mechanical/ chemical weathering processes. These data were used to build a predictive forward model for modal sandstone analysis that achieved a fair to good correlation between predicted and observed grain lithotypes and provenance categories. These results illustrate that the character of sands in the Umbum Creek catchment are governed by a multiplicity of controls such as tectonic setting, provenance lithotype analysis, climate, regional topographic gradient, hinterland transport distance, basin subsidence rate and depositional environment. The fluvio-aeolian depositional environment along with the current arid to semi-arid playa climatic conditions of Umbum Creek catchment facilitate the growth of clay coatings, however accounts for a low clay matrix within the deposits. In addition, the playa environment also facilitates the alteration of infiltrated detrital clay to kaolinite, the formation of evaporites (gypsum, halite and anhydrite) and the formation of authigenic clays. These factors are all significant in determining the ultimate reservoir quality of reservoir sandstones, emphasising the importance of this study as an analogue for modelling ‘buried’ dryland depositional systems. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1337211 / Thesis (Ph.D.) -- University of Adelaide, Australian School of Petroleum, 2008

Reservoir quality of subsurface sandstones depends on the composition, texture and grain size of the initial sediments. These factors are a function of hinterland processes: tectonic setting, provenance, climate and depositional environment, and sediment transportation processes. This study focuses on a modern, dryland, fluvial deposition system from source-to-sink that aims to provide a quantitative dataset analogue to facilitate forward modelling for prediction of subsurface compositions, grain size and textures of reservoir sandstones. Umbum Creek, in the western Lake Eyre Basin of Central Australia, was selected as a small river network (~ 100km²) in order to study source-to-sink sedimentation. The provenance area was analysed using isopach maps derived from a 783 drill-hole dataset, which included stratigraphy and lithology information. Subsequently forty-three samples of different provenance lithotypes from the Umbum Creek catchment were collected for petrographic thin-section analysis. Recent sediments were then sampled from 90 strategically located stream confluences along Umbum Creek and tributaries (proximal, medial and distal subsets). A quantitative textural and compositional dataset was subsequently generated from 34 selected samples. With half-phi sieve analysis (4mm to 32 microns), and an associated petrographic description recognising 72 categories of grain composition was undertaken for each sample. The provenance analysis using isopach maps demonstrated that Palaeozoic and Mesozoic sedimentary basin evolution in the study area was controlled by northeast and northwest-trending structural elements. The regional uplift of the Peake and Denison Inliers that occurred during the Cenozoic had a significant impact on the evolution of the Lake Eyre Basin, causing changes in the provenance of Late Neogene sedimentation and on through to the present. The sink area represents a shallow intracratonic basin whereby a thin veneer of fluvial/lacustrine sediments is accumulating adjacent to a basement uplift. This study has highlighted the importance of multiple sediment provenances. Five different provenance lithotype grains were identified in the Umbum Creek modern sediments: the Gawler Craton plutonic / basement provenance (recycled) the Peake and Denison Inliers Proterozoic volcanic provenance (recycled), the Davenport Ranges metamorphic provenance, the Mesozoic sedimentary provenance and the Cenozoic sedimentary provenance. Whereas a downstream fining of grain size was expected, a general trend of downstream coarsening of grain size was noted being the result of aeolian deflation of fines and intra-basinal coarse-grained sediment contributions. In the sink area, modern sediments from the terminal splay complex comprise 70-80% quartz, 10-20% lithic fragments (of which ~ 7% are ductile lithic grains), < 3% feldspar, and clay (<2%). Grains are sub-angular to well-rounded and moderately well sorted. The compositional and textural maturity of the terminal splay sediments is attributed to reworked plutonic quartz grains, the dissolution and disintegration of feldspar and carbonate grains during transportation, along with the breakdown of lithic fragments due to fluvio-aeolian interactions and subsequent mechanical/ chemical weathering processes. These data were used to build a predictive forward model for modal sandstone analysis that achieved a fair to good correlation between predicted and observed grain lithotypes and provenance categories. These results illustrate that the character of sands in the Umbum Creek catchment are governed by a multiplicity of controls such as tectonic setting, provenance lithotype analysis, climate, regional topographic gradient, hinterland transport distance, basin subsidence rate and depositional environment. The fluvio-aeolian depositional environment along with the current arid to semi-arid playa climatic conditions of Umbum Creek catchment facilitate the growth of clay coatings, however accounts for a low clay matrix within the deposits. In addition, the playa environment also facilitates the alteration of infiltrated detrital clay to kaolinite, the formation of evaporites (gypsum, halite and anhydrite) and the formation of authigenic clays. These factors are all significant in determining the ultimate reservoir quality of reservoir sandstones, emphasising the importance of this study as an analogue for modelling ‘buried’ dryland depositional systems. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1337211 / Thesis (Ph.D.) -- University of Adelaide, Australian School of Petroleum, 2008

Mineral dust aerosols, the tiny soil particles in the atmosphere, play a key role in the atmospheric radiation budget through their radiative and cloud condensation nuclei effects. It is therefore important to evaluate the radiative forcing of mineral dust and subsequent changes in atmospheric dynamics. The Weather Research and Forecasting with Chemistry (WRF/Chem) regional model with the integrated dust modules and available observations have been used to investigate the three-dimensional distribution of mineral dust over Australia. Additionally, the WRF/Chem model was used to estimate the direct radiative forcing by mineral dust over Australia. Particular emphasize has been given to direct radiative feedback effect of mineral dust on boundary layer dynamics. Two dust emission schemes embedded within the WRF/Chem model have been utilized in this study: the dust transport (DUSTRAN) and the Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) schemes. The refractive index of mineral dust depends on the mineralogy, size and composition of dust over a given region. The refractive index of mineral dust for shortwave radiation was considered to be wavelength independent and set based on previous mineralogical studies over North Africa and Australia. However, the refractive index of mineral dust for longwave radiation was considered to be wavelength dependent and to vary for 16 longwave spectral bands. Model results were compared with observations to validate the performance of the model, including satellite datasets from the Moderate Resolution Imaging Spectroradiometer (MODIS), Multi-angle Imaging SpectroRadiometer (MISR) and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), as well as ground-based measurements obtained from air quality monitoring sites over Australia. The major results can be summarized as follows: (1) Lake Eyre Basin is the most important source of dust in Australia, with a peak activity identified to be during austral spring and summer, and dust emission within the basin is often associated with the passage of dry cold fronts; (2) Mineral dust from Lake Eyre Basin can be transported long distances to southeastern Australia in association with eastward propagating frontal systems, reaching as far as New Zealand and beyond, and to northern tropical Australia by postfrontal southerly winds, and subsequently towards northwestern Australia and the Indian Ocean by southeasterly trade winds; (3) Australian dust plumes are mainly transported in the lower atmosphere, although variation of boundary layer depth during the passage of cold frontal systems, as well as ascending motion at the leading edge of these systems and descending motion where postfrontal anticyclonic circulation is dominant contribute to the vertical extent of mineral dust aerosols; (4) the shortwave direct radiative effect of mineral dust results in cooling of the atmosphere from the surface to near the boundary layer top, but warming of the boundary layer top and lower free atmosphere; (5) changes in the vertical profile of temperature result in an overall decrease of wind speed in the lower boundary layer and an increase within the upper boundary layer and lower free atmosphere; (6) the longwave warming effect of mineral dust partly offsets its shortwave cooling effect at the surface. This compensation is significantly larger over and immediately downwind of dust source regions where coarse particles are more abundant, as they have stronger interaction with longwave radiation emitted from the Earth’s surface; (7) both shortwave and longwave radiative forcing by mineral dust was found to have a diurnal variation in response to changes in solar zenith angle and in the intensity of longwave radiation, respectively; (8) the absorptive nature of dust was shown to be associated with the shortwave heating of the atmosphere; (9) on the other hand, longwave cooling of the atmosphere was identified because absorption of longwave radiation by dust is less than its emission to the surface and top of the atmosphere (TOA).

Understanding patterns of dispersal, the movement of individuals or propagules, among populations of riverine species is imperative to their management and conservation. However, directly estimating dispersal can often be difficult. Therefore, estimates of gene flow, the movement of genes, are often used to infer dispersal among natural populations. In riverine species, gene flow is determined by species biology, riverine architecture and flow regime. While many studies investigate the role of species dispersive strategies by comparing patterns of genetic structure in different species across the same geographic range, few also attempt to investigate the role of the non-biotic influences on gene flow in a comparative manner. Instead, studies regarding landscape processes (river architecture and hydrology) are based upon observations in a single riverine environment and not compared to other catchments that may differ in riverine architecture or hydrology. This study attempts to investigate all three factors influencing gene flow and genetic diversity using a comparative approach. This is done by contrasting two species of freshwater fish in two riverine systems that differ in their hydrological and structural makeup. By comparing patterns of genetic structure for each fish species, the role of species biology (behavioural and physical adaptations) can be explored. Then, by comparing patterns of genetic structure for each species, between riverine systems that differ in their landscape processes, the role of hydrology and riverine architecture in determining genetic structure can be explored. This study employed three different genetic markers to elucidate patterns of genetic structure and genetic diversity. These were, direct sequencing and screening of the control region of the mitochondrial DNA genome, microsatellite loci and allozymes...