G. Brent Hall

Fuzzy representation of geographical boundaries in GIS

Abstract Polygon boundaries on thematic maps are conventionally considered to be sharp lines representing abrupt changes of phenomena. However, in reality changes of environmental phenomena may also be partial or gradual. Indiscriminate use of sharp lines to represent different types of change creates a problem of boundary inaccuracy. Specifically, in the context of vector-based GIS, use of sharp lines to represent gradual or partial changes may cause misunderstanding of geographical information and reduce analysis accuracy. In this paper, the expressive inadequacy of the conventional vector boundary representation is examined. A more informative technique—the fuzzy representation of geographical boundaries—is proposed, in which boundaries describe not only the location but also the rate of change of environmental phenomena. Four methods of determining fuzzy boundary membership grades from different kinds of geographical data are described. An example of applying the fuzzy boundary technique to data analy...

Fuzzy information representation and processing in conventional GIS software: database design and application

Currently used methods for representing geographical information are inadequate because they do not tolerate imprecision. This leads to information loss and inaccuracy in analysis. Such expressive inadequacy is largely due to the underlying membership concept of classical set theory. To improve information processing in GIS research and application, an alternative membership concept is required. In this paper, we explore the inadequacy imposed upon geographical information representation by classical set theory and address the problems of information loss. A fuzzy relational data model is defined which is more representative for geographical information. A GIS database for agricultural land resource management is created by using the data model and a new technique for assessing land suitability is developed. The fuzzy representation largely facilitates data analysis in this GIS. The methods are tested with data from North Java, Indonesia using a vector-based GIS software package, Arc Info, and the analysi...

Community-based production of geographic information using open source software and Web 2.0

This article presents an innovative approach to citizen-led production of Web-based geographic information where new and/or existing digital map features are linked to annotations or commentary and citizens engage in synchronous and/or asynchronous discussion. The article discusses the relationship of the approach to public participation geographic information systems (PPGISs) and the emerging challenges associated with volunteered geographic information. A custom-developed, open source software tool named MapChat is used to facilitate the citizen inputs and discussions. The information generated from applying the approach through a series of community workshops is presented and discussed in light of current issues in PPGIS and volunteered geographic information research.

Social network transactions of psychiatric patients

In this research we examine self-reported social network transactions of former psychiatric inpatients residing in different types of housing in the community. Unlike earlier research, we found considerable reciprocity in network transactions with family and friends. Only professionals provided more support than they received from patients. Providing emotional support to others was positively correlated with positive affect, community integration, and mastery. Respondents reported more supportive than unsupportive transactions with network members and more supportive transactions with friends than with family or professionals. Finally, residents of supportive apartments and group homes provided and received support more frequently than residents of board-and-care homes. We discuss the results in terms of their implications for policy and future research.

Open Source Approaches in Spatial Data Handling

This book focuses on the nature and characteristics of open source geospatial (OSG) software. Therole of OSG approaches in spatial data handling is the cross-cutting theme of the book. Various sub-themes are explored that introduce readers unfamiliar to OSG software to the nature, purpose and applications of OS programming, and to the key new OS tools and their application within the geospatial data domain. The book also includes a discussion of new tools, approaches and applications for those already using OS approaches to software development.

Assessment of ambulance response performance using a geographic information system

The accessibility, distribution and utilisation of emergency medical services are important components of health care delivery. The impact of these services on well-being is heightened by the fact that ambulance resources must respond in a reliable and timely manner to emergency calls from demand areas. However, many factors, such as the unavailability of an ambulance at a center closest to a call, can adversely influence response time. This paper discusses the design and implementation of a framework developed in a Geographic Information System for assessing ambulance response performance. A case study of ambulance response in three communities in Southern Ontario, Canada is presented that allows easy and rapid identification of anomalous calls that may adversely affect overall operating performance evaluation. Extensions of the framework into a fully fledged service deployment and planning decision support system are discussed.

The extraction and utilization of local and scientific geospatial knowledge within the Bluff oyster fishery, New Zealand.

This paper assesses the Bluff oyster fishery in New Zealand as a case study in common pool resource management. It discusses ways in which modern information technology, augmented by low-tech data gathering strategies and community ethnography, can be used to produce an integrated scientific and local knowledge-inspired fishery database that lends itself to fostering collaboration in resource management and planning. The specific context and state of the oyster fishery in Bluff are described. Issues regarding undocumented and ephemeral intergenerational knowledge, much of which is geospatial in nature, on the fishery, the current crisis that many see in the future of the fishery, and a lack of cohesion or common sense of purpose between the stakeholder groups are discussed. It is argued that the digital resource that results from the integration of local and scientific knowledge and the potential community building processes that can ensue from collaboration and dialogue around this centrepiece are of central importance in developing an oyster fishery management plan that is holistic in concept and sustainable in purpose.

BALANCING CONSENSUS AND CONFLICT WITH A GIS-BASED MULTI-PARTICIPANT, MULTI-CRITERIA DECISION SUPPORT TOOL

Many land use decision problems are sufficiently complex, controversial and non-routine in nature that their resolution requires not only knowledge, expertise and data drawn from several distinct domains, but also debate of multiple and often conflicting viewpoints, objectives and solution strategies. Despite the promise of Geographic Information Systems (GIS) technology for examining a wide variety of land use issues, it has been criticised for its lack of decision support capabilities in this and other application areas (Hendriks and Vriens, 2000; Towers, 1997; Heywood et al., 1994). In particular, the capacity of commercial GIS to facilitate debate and achieve some measure of balance among different viewpoints has been identified as a major weakness. This capability is constrained by several factors in commercial software, foremost of which is an intrinsic single-user perspective that disregards the multi-interest character of the decision making process and the socially constructed nature of data and analytical methods (Pickles, 1999; Flowerdew, 1998; Jones et al., 1997; Goodchild, 1995).

Integration of Remote Sensing and GIS to Detect Pockets of Urban Poverty: The Case of Rosario, Argentina

The advent of high spatial resolution, multispectral satellite imagery has allowed analysis of remotely sensed images of urban land cover to become more useful to urban planning and decision making than in the past. The addition of radar imagery at relatively high spatial resolution (6 metres at best), with the advantages that it is not affected by cloud and diurnal light conditions and that it is sensitive to the targets geometric shape, surface roughness and moisture content offers additional capability in this regard. This paper incorporates analysis of Canadian RADARSAT-1 and American Landsat TM satellite imagery and ground-based GIS data to identify known pockets of urban poverty. Poverty is defined, based on a limited number of census variables related to dwelling construction materials and per household overcrowding. The objective is to provide a proof of concept that remote sensing data, especially from synthetic aperture radar, and ground-based GIS data can be successfully integrated for urban planning purposes. The results suggest that the approach used is reasonable and that, with future refinement, it offers planners and decision makers a timely and cost effective means to locate and monitor poverty pockets in urban areas. This is especially important in large, rapidly urbanising areas in the developing world.

A comparative evaluation of supportive apartments, group homes, and board-and-care homes for psychiatric consumer/survivors

In this research, we examined the processes and outcomes of supportive housing for psychiatric consumer/survivors. To determine the relative effectiveness of supportive apartments (SA) and group homes (GH) operated by non-profit mental health agencies, we used a longitudinal design with a non-equivalent comparison group of people residing in private, for-profit board-and-care homes (BCH). A total of 107 psychiatric consumer/survivors completed an initial interview and a follow-up interview one year later. Both quantitative and qualitative data were collected in the interviews. In terms of housing and social support processes, the residents of SA and GH were more likely to have their own room, to spend less of their income on rent, and to have more control in decision-making in the residences than people living in BCH. Residents of group facilities (GH and BCH) had more staff support, more emotional and problem-solving support, and less emotional abuse than residents of SA. The outcome analyses showed that residents in all three types of housing increased their involvement in instrumental roles (e.g., work, education) over time, and residents of SA and GH reported more changes in terms of personal growth and increased community involvement and showed increases in independent functioning, as rated by staff, than residents of BCH. However, none of the groups showed improvement over time on measures of perceived control, resident-rated independent functioning, meaningful activity, positive and negative affect, and life satisfaction. The results are discussed in terms of previous literature and implications for future research.