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)
    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)
    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 is 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)
    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 ; Blöschl, G ; Willgoose, GR ; McMahon, TA (AMER GEOPHYSICAL UNION, 1999-03)
    We analyze the degree of spatial organization of soil moisture and the ability of terrain attributes to predict that organization. By organization we mean systematic spatial variation or consistent spatial patterns. We use 13 observed spatial patterns of soil moisture, each based on over 500 point measurements, from the 10.5 ha Tarrawarra experimental catchment in Australia. The measured soil moisture patterns exhibit a high degree of organization during wet periods owing to surface and subsurface lateral redistribution of water. During dry periods there is little spatial organization. The shape of the distribution function of soil moisture changes seasonally and is influenced by the presence of spatial organization. Generally, it is quite different from the shape of the distribution functions of various topographic indices. A correlation analysis found that ln(a), where a is the specific upslope area, was the best univariate spatial predictor of soil moisture for wet conditions and that the potential radiation index was best during dry periods. Combinations of ln(a) or ln(a/tan(β)), where β is the surface slope, and the potential solar radiation index explain up to 61% of the spatial variation of soil moisture during wet periods and up to 22% during dry periods. These combinations explained the majority of the topographically organized component of the spatial variability of soil moisture a posteriori. A scale analysis indicated that indices that represent terrain convergence (such as ln(a) or ln(a/tan(β))) explain variability at all scales from 10 m up to the catchment scale and indices that represent the aspect of different hillslopes (such as the potential solar radiation index) explain variability at scales from 80 m to the catchment scale. The implications of these results are discussed in terms of the organizing processes and in terms of the use of terrain attributes in hydrologic modeling and scale studies. A major limitation on the predictive power of terrain indices is the degree of spatial organization present in the soil moisture pattern at the time for which the prediction is made.
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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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    [Review of the books Skunk works: a personal memoir of my years at Lockheed and The story of Webster's Third: Philip Gove's controversial dictionary and its critics]
    Park, Malcolm McKenzie (The Victorian Bar, 1995)
    Description of two creative men and their work products – innovative top secret US military aircraft and the current edition of Webster’s Third New International Dictionary.
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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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    Land information management at the World Bank
    Williamson, Ian P. ( 1991-03)
    The surveying, mapping and land information management industry in both the government and private sectors in Australia has increasingly promoted the export of its expertise to developing countries during the 1980s, particularly in the land administration area. This activity has brought the industry in closer contact with organizations such as the World Bank with a view to increasing Australia’s share of the international consulting market. As a consequence of these developments and the extensive expertise in land management within the World Bank, in both the operational and research areas, the author spent six months undertaking research in land information management in developing countries in the World Bank during the latter half of 1989. This paper summarizes his impressions and experiences from this period but in particular highlights the role and importance of surveying, mapping and land information management as perceived by the World Bank. A major conclusion of the paper is that the surveying profession together with its institutions, systems and technologies is ‘alive and well’ and has a very sound and important future in the developing world.
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    Cadastral reform: an Australian vision for the 1990s
    Williamson, Ian P. (Dienst van het Kadaster en de Openbare Registers, 1991)
    Ten years ago cadastral reform was not an issue in Australia. In fact, the term 'cadastre' was not even thought applicable in Common Law jurisdictions; today this view has changed. What is 'cadastral reform' and why has it become a key issue in Australasia over the last few years, are key elements of this paper.This chapter recognises that present Australian cadastral systems had their genesis in the 19th Century and, as a consequence, many of our practices, laws and regulations and institutional arrangements are not applicable in today's society. In reforming our cadastral systems, the paper looks at the major pressures which are instigating change. In particular, the chapter emphasises that an holistic approach is necessary in reforming cadastral systems while recognising that cadastral systems are fast becoming spatial information systems, in parallel with the community as it moves into the era of an information society.As an example of the growing interest in cadastral reform, the recent conference 'Cadastral Reform 1990', the first of its type in Australia, is reviewed.
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    No easy road: accountability in modern education for professional surveyors
    Hoogsteden, C. C. ; Williamson, I. P. ( 1991)
    In any economy where public expenditure on higher education accounts for a sizeable proportion of Gross Domestic Product (GDP), equity in spending and equality of access have long been considered to be crucial issues in the political arena. They still are. However, we now find that it is concerns about the efficiency of higher education provision, and especially its quality, form, content and relevance, which are now expressed most stridently. In turn, this has led to demands for more coherent planning and management control systems in higher education generally within which the accountability of the institution, the professional school and the individual academic is a sine qua non. Then, in the space of a decade or so, the well-defended vocational walls which have surrounded land information professionals, especially land surveyors, have begun to be breached in many parts of the world. Primarily, this process is due to the advent of new information and positioning systems, including Land Information Systems (LIS), Geographical Information Systems (GIS) and Global Positioning Systems (GPS) over which surveyors have no particular lien. This has been coupled with other powerful external forces such as professional deregulation. Quite simply, there is a new game, new turf and new players. Things are not what they used to be - nor will they ever return to what they were. Unfortunately, many wish that they would and a laager mentality is still alive and well in the worlds of surveying academe and professional surveying practice alike. Yet, some individuals and institutions have, with not a little delight, welcomed the opportunities which change invariably brings and, moreover, achieved success. This success is due, in no small way, to the vigorous adoption of a variety of innovative measures of modern academic management including the process of proper accountability and the introduction of performance indicators. There is also the matter of a growing and increasingly vociferous consumer lobby. In a number of countries, including Australia, New Zealand and Great Britain, tertiary students have had to sustain substantial increases in direct charges for their courses. In practice, the alternative cost-recovery mechanisms range across the charging spectrum and include: full-cost fees, supplementary top-up fees for certain courses, repayable loans and inflation-indexed graduate taxes. Yet, whatever the charging mechanism, it would be surprising if the natural querulousness of students regarding their education anyway were not intensified by the forceful expression of dissatisfaction if they consider the education they receive as representing poor value for money. It would also be surprising if there is not increased pressure from both public-sector and private-sector employers of surveying graduates for greater accountability to be demonstrated by those involved in professional surveying education. Many of these employers have been put through an "economic wringer" by governments set on obtaining efficiency and effectiveness in the national economy. Moreover, to survive in the medium term and long term, they know that they need that essential input which comes from fresh, active, and capable young minds able to respond to the new challenges, not those of twenty years ago. To put it bluntly, academic accountability is not just a fashionable word. Increasingly, it is a powerful and necessary, albeit emotive, issue for governments, tertiary-education institutions, individual academics, tax-payers and students alike. The reality of the academic environment today is that the introduction of accepted management practices - strategic plans, performance appraisal and business plans to name but three - are all becoming part of the daily routine. However, a major problem which accompanies the introduction of increased accountability for the tertiary-education sector in Australia lies with the lack of proper provision, within the new performance appraisal process, for financial rewards for individual high-achieving academics. This contrasts markedly with the private sector and, indeed, with some parts of government where performance payments are the norm. Thus, in a sense, the tertiary-education sector has been both squeezed by government and also put through the "economic wringer" as well. Moreover, this has happened at a time in Australia when academic salaries have fallen, in relative terms, well behind teachers and other related professionals. The net, and worrying, result is that many of the best people are leaving universities, while at the same time it is very difficult to attract suitable professionals into the tertiary-education sector. The purpose of this paper is four-fold. First, we outline what is meant by accountability. Then, we will explore the manner in which accountability fits into the rapidly-changing world of higher-education management. The third objective is to examine the various inter-mingled relationships and responsibilities of the major role-players in professional surveying education. Finally, we consider the need for and introduction of suitable performance indicators to provide an essential underpinning to the academic accountability process. We offer no apology for using the management practices at the University of Melbourne as an example throughout the paper. Quite simply, it is sensible to comment on that which one knows well. Moreover, in dealing with some issues of potential contention and sensitivity, it seemed more prudent to remain reasonably "close to home". Naturally, it is recognised that similar processes would be found in other institutions to varying degrees.