Infrastructure Engineering - Research Publications

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    The behavior of stratified pools in the Wimmera River, Australia
    Western, AW ; ONeill, IC ; Hughes, RL ; Nolan, JB (AMER GEOPHYSICAL UNION, 1996-10-01)
    Numerous inland Australian streams contain density-stratified or saline pools, which are usually located on channel bends. Saline pools consist of a layer of saline water underlying a layer of fresh water. Saline pools generally form as a result of saline groundwater seeping into the stream and collecting in scour depressions during periods of low flow. Inflows of saline river water can also collect in scour depressions. Field and laboratory investigations of saline pool mixing by overflowing fresh water reveal that mixing depends on a balance between interfacial shear and buoyancy forces acting on a thin dense layer flowing up the downstream slope of the scour depression, and on the bend sharpness. Convection associated with surface cooling also causes mixing. A model for saline pools formed by groundwater inflows and mixed by fresh overflows is proposed and applied to several saline pools in the Wimmera River.
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    Preferred states in spatial soil moisture patterns: Local and nonlocal controls
    Grayson, RB ; Western, AW ; Chiew, FHS ; Bloschl, G (AMER GEOPHYSICAL UNION, 1997-12-01)
    In this paper we develop a conceptual and observational case in which soil water patterns in temperate regions of Australia switch between two preferred states. The wet state is dominated by lateral water movement through both surface and subsurface paths, with catchment terrain leading to organization of wet areas along drainage lines. We denote this as nonlocal control. The dry state is dominated by vertical fluxes, with soil properties and only local terrain (areas of high convergence) influencing spatial patterns. We denote this as local control. The switch is described in terms of the dominance of lateral over vertical water fluxes and vice versa. When evapotranspiration exceeds rainfall, the soil dries to the point where hydraulic conductivity is low and any rainfall that occurs essentially wets up the soil uniformly and is evapotranspired before any significant lateral redistribution takes place. As evapotranspiration decreases and/or rainfall increases, areas of high local convergence become wet, and runoff that s generated moves downslope rapidly wetting up the drainage lines. In the wet to dry transitional period a rapid increase in potential evapotranspiration (and possibly a decrease in rainfall) causes drying of the soil and 'shutting down' of lateral flow Vertical fluxes dominate and the 'dry' pattern is established. Three data sets from two catchments are presented to support the notion of preferred states in soil moisture, and the results of a modeling exercise on catchments from a range of climatic conditions illustrate that the conclusions from the field studies may apply to other areas. The implications for hydrological modeling are discussed in relation to methods for establishing antecedent moisture conditions for event models, for distribution models, and for spatially distributing bulk estimates of catchment soil moisture using indices.
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    The Tarrawarra data set: Soil moisture patterns, soil characteristics, and hydrological flux measurements
    Western, AW ; Grayson, RB (AMER GEOPHYSICAL UNION, 1998-10-01)
    Experiments investigating the spatial variability of soil moisture conducted in the 10.5 ha Tarrawarra catchment, southeastern Australia, are described. The resulting data include high-resolution soil moisture maps (over 10,000 point measurements at up to 2060 sites), information from 125 soil cores, over 1000 soil moisture profiles from 20 sites, 2500 water level measurements from 74 piezometers, surface roughness and vegetation measurements, meteorological and hydrological flux measurements, and topographic survey data. These experiments required a major commitment of resources including 250 person days in the field, with a further 100 person days in the laboratory preparing for field trips and checking and collating data. These data are available on the World Wide Web (http://www.civag.unimelb.edu.au/data/).
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    Observed spatial organization of soil moisture and its relation to terrain indices
    Western, AW ; Grayson, RB ; Bloschl, G ; Willgoose, GR ; McMahon, TA (AMER GEOPHYSICAL UNION, 1999-03-01)
    The degree of spatial organization of soil moisture, and the ability of terrain attributes to predict that organization was analyzed. The measured soil moisture patterns exhibited a high degree of organization during wet periods due to surface and subsurface lateral redistribution of water. The shape of the distribution function of soil moisture changed seasonally and was influenced by the presence of spatial organization. A correlation analysis found that ln(a), where a is the specific unslope area, was the best univariate spatial predictor of soil moisture during wet periods and up to 22% during dry periods.
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    [Review of the book Fermat's last theorem]
    Lewin, E. ; Park, M. M. (The Victorian Bar, 1997)
    Two recent books celebrate the long sought solution of a venerable maths problem.
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    Groundwater Quality Hydrogeological Assessments
    Lane, Mr Anthony ; Leonard, Mr John ; Weaver, Dr Tamie R ( 1999)
    Groundwater is a vital resource in Victoria. The Environment Protection Authority (EPA) and other authorities recognise the need to protect the quality of groundwater as a resource and as part of the natural environment. Hydrogeological Assessments (HAs) is one of the tools used to provide the information necessary to determine the status of groundwater quality or the effects of a proposal on the beneficial uses of groundwater. For example, a proponent of a new landfill or industrial development with potential to impact groundwater is likely to be required to perform a HA. The HA guidelines that have been published by EPA (EPA publication 668) provide an overview of HA methodologies, and the reasons for using different investigative techniques. The document presented here is a background document. It was commissioned and funded by the EPA; however it was never published by EPA. Instead, this document formed the basis for development of the guidelines, Hydrogeological Assessments (Groundwater Quality) Guidelines, published by EPA in August 2006.
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    Establishing coordinated cadastres: Australian experiences
    Williamson, Ian P. ( 1996)
    Australian cadastral systems have been strongly influenced by the historical settlement of the Australian states and territories. An important consequence is that no cadastral office was ever established and as a result a coordinated cadastre never developed. Departments of Lands or Surveyors General departments administered the ever decreasing Crown lands as a result of rapid alienation, as well as the jurisdictions' surveying and mapping infrastructure. As a result Australia lacked a European style cadastral office providing a complete cadastral record which could be used for land administration purposes. Land Titles Offices historically had the responsibility for all freehold or private lands, which now comprise the vast majority of land parcels in the states. These Offices have been responsible for examining all cadastral surveys and ensuring appropriate regulations for such surveys, however they have only ever been concerned with individual transactions in support of an efficient land market. The maintenance of the cadastral map for each jurisdiction however has usually remained under the control of the Surveyor General or in recent years a geographic information coordination agency. Increasingly the title register in each jurisdiction is including all Crown and government lands and is assuming the role of a European cadastre, albeit the cadastral index has legal significance since it is based on actual land titles. Due to computerisation of the titles register and the establishment of digital cadastral data bases (DCDB), the trend in Australia is for the textual and spatial components of the cadastre to come together technically and administratively. This has allowed Australian jurisdictions for the first time to have a complete cadastral record to support land administration. The resulting model has permitted Australia to move from a land administration structure that was conceptually well behind that of most developed and many developing countries to a position at the forefront of developments due to innovation and computerisation. The development of coordinated cadastres formed by upgrading the now complete DCDBs in Australia is the key in the future improvement of Australia's cadastral systems. This paper reviews this development and shows how the Australian systems differ from their European counterparts. It concludes by attempting to describe a future conceptual model for an Australian state wide geographic information system based on a legal cadastre. Australian states and territories are well advanced to achieving this vision.
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    A land information vision for Victoria
    WILLIAMSON, IAN ( 1996)
    Objective: To develop a vision and milestones to achieve the vision, for the use and management of land parcel related spatial data (here after termed land information) in Victoria in ten years. While the primary focus of the vision is on land parcel data, the vision recognises that to be useful and effective, land parcel data needs to be integrated with or utilise other appropriate components of the State's digital map base (SDMB), and particularly the topographic data. This vision must complement the other visions being prepared by the Victorian Government as part of the development of a holistic vision for the management of spatial information in Victoria. The other visions include: • Environment and Heritage • Industry Development • Socio-Economic Planning • Intermodal Transport • Emergency Response
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    Appropriate cadastral systems
    WILLIAMSON, IAN ( 1996)
    Cadastral systems are not ends in themselves and support effective land markets, increased agricultural productivity, sustainable economic development, environmental management, political stability and social justice, although it is absolutely essential that each cadastral system is designed appropriately to serve the needs of the individual country.
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    Understanding cadastral maps
    WILLIAMSON, IAN ; ENEMARK, STIG ( 1996)
    Cadastral maps are generally regarded as an essential part of the land management infrastructure in most countries yet there is often misunderstanding about their characteristics and role. Due to the vast range of different cadastral systems and resulting cadastral maps, it is very difficult to describe a “typical” cadastral map. It is the authors’ view that it is also very difficult, if not impossible, to understand the characteristics and functions of a cadastral map without understanding the respective cadastral system. As a result this paper endeavours to examine the characteristics and functions of cadastral maps by examining the cadastral mapping systems in Denmark and Australia. The Danish system is a typical “old world” European system which had its history in land taxation. The Australian systems could be considered “new world” systems which have been more heavily influenced by land market considerations. Even though the Australian and Danish cadastral systems are very similar, understanding the characteristics and functions of cadastral maps in the two systems remains difficult. This study discusses the different characteristics of cadastral maps which have been designed for different users or functions. In particular the paper concentrates on the issues concerned with developing digital multi-purpose cadastral maps. The major conclusions from the paper are that the creation and maintenance of multi-purpose digital cadastral maps is a difficult and complex task. This complexity arises to a large degree because the characteristics of a cadastral map designed to serve traditional land markets or land registration purposes are quite different from the characteristics of a modern multi-purpose cadastral map.