Infrastructure Engineering - Research Publications
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ItemThe behavior of stratified pools in the Wimmera River, Australia(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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ItemEstablishing coordinated cadastres: Australian experiences( 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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ItemA land information vision for Victoria( 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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ItemAppropriate cadastral systems( 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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ItemUnderstanding cadastral maps( 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.
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ItemAppropriate cadastral systems( 1996)This paper discusses the role of cadastres in developing countries, reviews why cadastral systems have become much more important in the eyes of policy makers over the last ten years, particularly in developing worlds, and finally highlights some important lessons arising from establishing cadastral systems in developing countries over the past decade.
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ItemCoordinated cadastres: a key to building future GIS( 1996)One of the main reasons for the growth in the use of geographic information systems (GIS) has been the availability of digital spatial data. All states and territories in Australia have been moving to provide a range of core spatial data sets as part of their spatial data infrastructure to support GIS. It is accepted in Australia that the most important core data set is the cadastral parcel framework or digital cadastral data base (DCDB). Without such an up-to-date DCDB it is difficult if not impossible for many local government and utility information systems to exist. This paper focuses on the growth of DCDBs in Australia and the very significant technical and institutional changes in the operation and management of DCDBs, particularly over the last few years. Australian jurisdictions have only recently completed the first version of their DCDBs which have generally been created by digitising the best available maps. These DCDBs have accuracies of about 1 mm at map scale (2.5 m at 1:2,500). The next decade will see the development of survey accurate DCDBs updated by coordinated cadastral surveys (in other words coordinated cadastres). These DCDBs will have an accuracy of coordinates of parcel corners of approximately 0.03m in urban areas, 0.2-0.3m in rural areas and 0.5-2m in large properties or mountainous terrain. This will present new opportunities for GIS administrators and will have the potential of dramatically changing the way many activities in organisations are undertaken. Some states and territories are already well on the way to establishing such systems, while all are heading generally in this direction. As a result it is important for GIS administrators to be aware of these changes and potential opportunities. This paper reviews the development of cadastral systems in Australian jurisdictions and examines the moves to establish coordinated cadastres based on survey accurate DCDBs. The paper concludes by attempting to describe a future conceptual model for an Australian state wide geographic information system based on a legal cadastre. In particular it highlights the form of the future core spatial data set providing the land parcel framework and the associated textual or graphic data sets, all of which will be available remotely.
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ItemData flows, standards and incremental cadastral update( 1996)The initial map captured digital cadastral database (DCDB) is undergoing a continual update and upgrade cycle as new cadastral data is added and old data is revised. The role of the DCDB as a spatial reference for Geographic Information Systems (GIS) in local government and the utility companies has firmly established them as customers (Wan and Williamson, 1995). The custodians of the DCDB must now tackle the problem of acquiring and distributing these incremental updates and upgrades. This paper examines the incremental data flow both into and out of the DCDB for the two Australian states of New South Wales and Victoria. This transfer of cadastral data is modelled from the surveyor as the supplier of the data through to the customers of the DCDB. One of the many considerations in the propagation of the incremental update is specifying the format and standards for the data and of the data transfer. The paper looks at the planning of these two states in regard to transfer standardisation and the possible use of transfer standards such as the Spatial Data Transfer Standard (SDTS).
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ItemInternational trends in cadastral reform( 1996)In addressing the topic of international trends in cadastral reform, the paper overviews some of the current or recent projects or activities concerned with cadastral issues which have recently been undertaken by or involved the author. Even though a number of the projects focus on Australia, collectively they give some indication of current issues and trends worldwide in cadastral reform, both in developing and developed countries. The paper describes each project or activity briefly and then endeavours to identify one or two major issues or lessons arising from each project. The projects or activities discussed include: •the activities of Commission 7 (Cadastre and Land Management) of the International Federation of Surveyors (FIG) •the preparation of the FIG "Statement on the Cadastre" •the justification of cadastral systems in developing countries •the incorporation of traditional or customary tenures in "Western" cadastral systems •the importance of focussing on cadastral processes vs cadastral components in cadastral reform •understanding cadastral maps •establishing and maintaining digital cadastral data bases •understanding the Australian cadastral system •establishing coordinated cadastres in Australia •the relationship of the cadastre to the spatial data infrastructure of a state or country •economic issues in cadastral reform •the role of the cadastre in managing cities •the politics of cadastral and spatial information systems.
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ItemA model of the decision process for GIS adoption and diffusion in a government environment( 1996)The way a government organisation conducts its business can be viewed as a public management system, consisting of a ‘public production process’ in an organisational setting. In this system, many factors interact with one another to make it operate. Accordingly, the decision for the adoption and diffusion of GIS in such a system also will be subject to the influence of these factors. Based on the experience of GIS adoption and utilisation observed in several Australian State government agencies in 1995, seven such factors are identified, namely, GIS paradigm, aligned vision of decision makers, production infrastructure, production process, product mix, organisational setting, and the external environment of the stakeholders. Their relationships are described in a model which confirms the need for alignment between GIS and these factors in a government organisation. It is hoped that the model will contribute to the theoretical understanding of the process of GIS diffusion in a government environment, and as a result, facilitate the planning and management of the process in future.