Thesis (M. Sc.)--University of Hong Kong, 2005.

No description available.

Effective information communication and public participation in the planning process are important elements for facilitating successful environmental decision-making. Previous research has demonstrated the importance of such factors for delivering benefits to a wide range of stakeholders in the planning system by increasing the transparency and efficiency of the planning process. Given the current problems facing onshore wind farm planning in the UK there is an urgent need to investigate alternative approaches for enhancing the quality of information dissemination and public participation in the planning process. Planning information relating to the potential visual impacts of wind farms is particularly important in the case of the wind farm planning, given the high levels of concern amongst members of the public regarding the perceived negative visual impact of proposed wind turbines on the landscape. However, shortcomings associated with traditional techniques used to assess such impacts have been highlighted in previous research, along with drawbacks related to the dissemination of such information to the public during the planning stages of wind farm development. This has been shown to affect the overall quality of public participation in the planning process. This research is concerned with evaluating the potential of innovative digital landscape visualisation and Internet-based techniques for addressing some of the shortcomings in these areas. This thesis describes the implementation of two survey studies designed to meet these objectives. The first study uses a postal questionnaire approach in order to determine the current 'state-of-play' regarding the levels of use of such innovative techniques for improving impact assessment and information dissemination in wind farm planning. In addition to a review of the existing literature, the findings of the survey provide further rationale for conducting the second (Internet-based) survey study, designed to evaluate the potential of online visualisation-based approaches for improving the quality and dissemination of visual information, and enhancing public participation in wind farm planning. The survey is based on visualisations created for an actual proposed wind farm development in South Wales, UK. The findings reinforced much of the existing research literature, confirming that innovative visualisation and Internet-based approaches do have good potential for augmenting existing methods of visual information creation, dissemination and public participation although a variety of observations and concerns were raised by survey respondents that highlighted the potential limitations of such approaches. Further avenues for research are then identified.

Most GIS systems use separate thematic "layers" to store different types of spatial data. Each of them contains specific characteristics of the area, so there are separate layers for the distribution of buildings, the road network or the relief of the terrain. The spatial information used in GIS can be grouped into four main groups: polygonal maps, terrain models, networks and discrete, unconnected objects. Polygonal maps and terrain models are considered to be "field" models of space, covering the whole map, so there is some kind of information available at every location. On the other hand, networks and discrete objects are representations of the "object" model of space, in which the map is populated by entities and the space between them is empty. Choropleth maps are the most common examples of polygonal maps and the three main representations of terrain models are Triangular Irregular Networks (TINs), grids and contour lines. Networks consist of connected edges, while discrete objects can be points, lines or polygons. In networks, polygonal maps and surfaces there is some model of connectivity available. Polygons are adjacent to each other, as are the elements in terrain models. Network data is connected along the edges and junctions are defined. Unconnected objects need have no connectivity information, but in that case the possible spatial queries are limited. The layers can be stacked on top of each other to perform various operations and analyses on them. However, there is no consistent method applicable to all data types because GIS has traditionally separated field and object layers and used different data structures to represent them. This thesis presents a unified spatial data model for these most common types of spatial information and intends to show that it has clear advantages for geographical analysis. The idea is to represent discrete object models as fields, so there is information available at all locations. The model is based on the Voronoi Diagram (VD) and the dual Delaunay Triangulation (DT), two well studied geometric structures. Depending on the application it may be appropriate to represent the data on the map by the simple VD/DT, or their derivatives - the Constrained DT (CDT), the Line Segment VD (LSVD) or the crust and the skeleton. All of these are directly related to each other and may be handled in a single manner in the computer. Algorithms and the storage of these various forms of the VD using the quad-edge data structure is described. This structure may be updated locally, and dynamic algorithms for each of these representations are presented. This allows for the development of a common interactive framework for what are traditionally considered to be distinct data types. The unified model is illustrated by a variety of GIS applications, and the implementation of several traditional GIS operations and queries is discussed.

A number of GIS architectures and technologies have emerged recently to facilitate the visualisation and processing of geospatial data over the Web. The work presented in this dissertation builds on these efforts and undertakes to overcome some of the major problems with traditional GIS client architectures, including application bloat, lack of customisability, and lack of interoperability between GIS products. In this dissertation we describe how a new client-side GIS architecture was developed and implemented as a proof-of-concept application called RADGIS, which is based on open standards and emerging distributed component-based software paradigms. RADGIS reflects the current trend in development focus from Web browser-based applications to customised clients, based on open standards, that make use of distributed Web services. While much attention has been paid to exposing data on the Web, there is growing momentum towards providing “value-added” services. A good example of this is the tremendous industry interest in the provision of location-based services, which has been discussed as a special use-case of our RADGIS architecture. Thus, in the near future client applications will not simply be used to access data transparently, but will also become facilitators for the location-transparent invocation of local and remote services. This flexible architecture will ensure that data can be stored and processed independently of the location of the client that wishes to view or interact with it. Our RADGIS application enables content developers and end-users to create and/or customise GIS applications dynamically at runtime through the incorporation of GIS services. This ensures that the client application has the flexibility to withstand changing levels of expertise or user requirements. These GIS services are implemented as components that execute locally on the client machine, or as remote CORBA Objects or EJBs. Assembly and deployment of these components is achieved using a specialised XML descriptor. This XML descriptor is written using a markup language that we developed specifically for this purpose, called DGCML, which contains deployment information, as well as a GUI specification and links to an XML-based help system that can be merged with the RADGIS client application’s existing help system. Thus, no additional requirements are imposed on object developers by the RADGIS architecture, i.e. there is no need to rewrite existing objects since DGCML acts as a runtime-customisable wrapper, allowing existing objects to be utilised by RADGIS. While the focus of this thesis has been on overcoming the above-mentioned problems with traditional GIS applications, the work described here can also be applied in a much broader context, especially in the development of highly customisable client applications that are able to integrate Web services at runtime.

This research takes as its starting point the past decade of critiques from human geographers, and proposes an alternate model for appraisals of technology. The first section begins with an analysis of the bases and motivation of external assessments of GIS. A historiographical account reveals that the critical impulse among human geographers was not static, but evolved to incorporate greater subtlety based on cooperation with GIS scholars. Critiques from human geographers, nevertheless, had a profound impact on the discipline, and practitioners of GIS frequently felt that their perspectives on issues including the roots of GIS, its epistemological bases, and its ethics had been undervalued by critics. A re-analysis of critiques, from the perspectives of GIS practitioners, investigates objections to critical accounts of the technology. The second half of the research builds upon existing critiques and responses to them, but asks the question, "is there a more constructive means to engage with technology, from a theoretical perspective?" Two contemporary research questions in GIS are investigated, as a means of establishing a preliminary methodology for critique that engages with GIS at a conceptual, as well as a technical level. Factors that have influenced the progress of automated generalization are examined in some detail. The argument is made that both social and digital parameters define the technology, and it is unproductive to focus on one at the expense of the other. The second research question concerns data models and the extent to which fields and objects are inevitable. The case is made that a web of historical and scientific justification has prevented researchers from seeking alternatives to the atomic and plenum views of space. Finally, an appeal is made for continued theoretical examination of the technology as part of an effort to develop geographic information science. / Arts, Faculty of / Geography, Department of / Graduate

Includes bibliographies. / The Department of Water Affairs and Forestry (DWAF) acquired a Geographic Information System (GIS) in 1987. The purpose of acquiring such a system was to aid the department in implementing their water resource management strategy of that time. On acquiring this system it was well recognised that the GIS would need to communicate geo-referenced information, generated by analysis and modelling to decision makers by means of graphic representations or maps (Olivier et al., 1990: 14 73). Towards the end of 1990 it became apparent that the department needed to standardise cartographic output of this system. Maps on the same theme, which were produced at different sites were not comparable and graphic communication was not effective. A consultant was appointed, who, in conjunction with the departmental digital cartographer, established criteria and standards which were flexible enough to accommodate mapping on a wide variety of themes. These standards were implemented, to a limited extent in July 1994. Standards were set for map encoding, map content and map composition. This report investigates how effective these standards have been. The effectiveness of these standards have been measured in terms of the five recognised cartographic design principles that have been identified by Robinson et al. (1984), Wood (1992) and Dent (1990). These include the clarity and legibility of maps, the distinction between figure and ground, the hierarchical organisation of mapped information, the visual contrast of marks on maps and the visual balance or layout of the finished map. A sample of maps made after the implementation of cartographic standards at the department was compared to a sample of comparable maps made prior to the implementation of these standards. In a large organisation like the department the success of such standards do not depend on the standards alone but also on their implementation. Implementation related problems were identified by comparing standardised maps with the standards. The outcome of the investigation proved that the effectiveness of graphic communication had indeed improved albeit to a varying degree. In most cases the standards were adequate and the main problems actually lay with their implementation. Recommendations on the implementation and the few aspects of the standards that require amendment have been included in this report.

Hurricane evacuation refers to an individual’s or household’s response to a hurricane threat by temporarily relocating somewhere safe. However, it is rarely the case that everyone will comply when he/she is ordered to evacuate by authorities. Understanding why people fail to heed evacuation orders is vital in order to minimize non‐compliance. In the past, factors contributing to hurricane evacuation behavior have been studied mainly using survey instruments. The most significant variables include official evacuation orders, housing type, perceived risks, environmental cues, and social cues. Factors such as information sources, experience, and demographic characteristics have weaker impacts on evacuation decisions or are significant in only a limited number of studies. In this study, many of the literature‐documented factors that contribute to evacuation behavior were examined using survey data collected in Charlotte County, Florida, before and after Hurricane Irma (2017). Additional environmental factors, some of which were not included in a majority of the previous hurricane evacuation studies, were examined together with the survey‐based, socioeconomic, and risk‐perception variables. Environmental factors examined less frequently include variables such as the structural characteristics of people’s homes, storm surge zone, wind zone, and distance to shelters. Environmental variables examined in the previous literature include elevation, flood zone, and distance to the coastline. These data were collected through publicly available data sources and linked with the survey respondents’ home locations. The literature review points to the importance of risk perception on people’s hurricane evacuation decision‐making, so factors that may have contributed to people’s hurricane risk vi perception were also examined. These factors include both the survey‐based socioeconomic variables and the GIS‐derived environmental factors described above. Risk perception in this study was measured through the respondent’s answers to a question regarding their sense of safety in a hypothetical Category 3 hurricane. Since an individual’s perception of safety is an overall measure of whether people think they are threatened by particular hurricane‐induced risks (such as flood damage, wind damage, and power loss), the term perceived vulnerability was adopted and used throughout the entire thesis. In this study, perceived vulnerability refers to a respondent’s overall sense of safety when they consider all the potential threats associated with a Category 3 hurricane. Descriptive statistics, chi‐square test, and independent samples t‐test were performed to assess for associations between independent variables and the two dependent variables. One of the dependent variables is the evacuation decisions made by the survey respondents in Charlotte County in response to Hurricane Irma. The other dependent variable is perceived vulnerability. Logistic Regressions were performed for each dependent variable with only significant factors (according to the chi‐square or t‐test analysis) input as the independent variables. The results showed: 1) For survey respondents in Charlotte County living within evacuation zones A and B (both were under mandatory evacuation orders during Hurricane Irma), education level, perceived hurricane evacuation zone, perceived vulnerability, and distance of residence to the nearest coastline were statistically significant factors associated with the evacuation decisions made during Hurricane Irma. 2) According to Logistic Regression, perceived vulnerability and the distance from the subject’s home to the nearest coastline were vii the most significant factors influencing the evacuation decisions made during Hurricane Irma. 3) For survey respondents living across Charlotte County regardless of evacuation zones, many socioeconomic, risk perception, and environmental factors were statistically significantly associated with their perceived vulnerability. 4) When these factors were included in the Logistic Regression analysis, the respondent’s storm surge zone and their belief that their houses were located in a low‐lying area, were the factors found to be most significantly associated with perceived vulnerability. This study contributes to the assessment of people’s hurricane risk perception and evacuation decisions. It also demonstrates the benefit of including environmental variables in hurricane risk perception and evacuation decision‐making research. Many factors, including less‐researched environmental variables, were integrated into this comprehensive study. Perceived vulnerability, a measure of overall perceived risks, was found to be the most significant factor associated with people’s hurricane evacuation decisions. It was found more important than whether people believe they heard evacuation orders or what type of evacuation order they heard. Evaluating what determines people’s perceived vulnerability is a relatively new research direction in studies examining hurricane evacuation behavior. In this study, many of the environmental variables (such as elevation, the distance of the home to the nearest coastline, evacuation zone, and storm surge zone) were found to be significantly associated with people’s perceived vulnerability. For the subjects in this study, fear of flooding was identified through the two significant variables standing out in the Logistic Regression analysis – respondent’s storm surge zone (an environmental factor) and respondent’s belief that their home is located viii in a low‐lying area (a specific risk perception factor). This finding may be useful to government officials when they communicate with the public prior to a hurricane making landfall. Including information such as flooding risks may motivate residents to comply with evacuation orders. / A Thesis submitted to the Department of Geography in partial fulfillment of the requirements for the degree of Master of Science. / 2019 / November 13, 2019. / GIS, Hurricane Evacuation, Perceived Vulnerability, Risk Perception / Includes bibliographical references. / Tingting Zhao, Professor Directing Thesis; James Elsner, Committee Member; Sandy Wong, Committee Member; Earl Jay Baker, Committee Member.

Thesis (MTech. degree in Nature Conservation)--Tshwane University of Technology, 2008. / Wildlife monitoring is fundamentally necessary to understand how ecosystems function and how environmental changes affect wildlife populations and natural habitats. Traditionally wildlife monitoring has relied primarily on statistical analysis to interpret trends and patterns. A constraint of these techniques is an inability to detect spatial changes over time. This study investigated the use of geographic information systems (GIS) to add a spatial context to both short- and long-term wildlife monitoring.

Thesis (M.S.)--Texas State University-San Marcos, 2008. / Vita. Appendices: leaves 55-56. Includes bibliographical references (leaves 57-60). Also available on microfilm.