摘要:

The traditional home of GIS in terms of managing,mapping, modelling and making decisions based on spatial data has been in the land-based sciences and professions. This has resulted in a concentration of GIS on land-based 'application domains' (sets of GIS applications with common properties and data formats), with a relatively homogeneous group of users and applications addressing the solutions of largely related problems. This atmosphere has tended to obscure the essential nature of GIS as an ubiquitous, heterogeneous tool, having utility far beyond land-based problems. We must consider remedying this if we expect GIS to play an increasingly important role in Earth system science or global change research. We therefore propose the expansion of a largely landbased GIS research agenda to the development of systems focusing more on the marine environment, for there are many ways that GIS may be improved by tackling the problems associated with oceanographic data. The discussion is confined largely to deep ocean science which rarely appears in the GIS or geographical literature (as opposed to coastal zone studies). We identify research issues endemic to oceanographic applications of GIS that will advance the body of knowledge in GIS design and architecture, as well as the body of knowledge in the broader field of geographical information science. They include the development of spatial data structures with the ability to vary their relative positions and values over time, geostatistical interpolation of data that are sparse in one dimension but abundant in the others, and new data models that make the feature-based query, search and retrieval of objects and continuous fields in very large spatial databases more efficient.

ISSN:1365-8816    

DOI:10.1080/136588197242176

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The use of Spatial Access Methods (SAMs) in spatial database systems, such as Geographical Information Systems, is necessary to achieve efficient retrieval of data items according to their spatial properties. Existing SAMs organizing minimum bounding rectangle (MBR) approximations of spatial objects can be classified into four groups. Each group is characterized by the special technique adopted for managing MBRs: (a) Ordering, (b) Transformation, (c) Clipping, and (d) Overlapping. This paper introduces a new technique. The basic idea of this technique is to represent all spatial objects by their MBRs and further reduce them into points of the same dimensionality, so that any multidimensional Point Access Method (PAM) may be used to support access. Essential for the functionality of the new method is the query window extension. The results of both analytical and experimental work show that SAMs using the new technique clearly outperform popular SAMs, such as the R- and R*-trees for data sets consisting of equal-sized MBRs. As for data sets of varying MBR sizes a competitive performance can be obtained.

ISSN:1365-8816    

DOI:10.1080/136588197242185

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

A graph-theoretic data model, XRAG (eXtended Relational Attributed Graph), is described. The model and its associated data structure can be used to represent the structural properties (morphological and symbolic) of, and relations (spatial, topological, non-topological, quantitative and symbolic) between, discrete regions identified in a digital remotely-sensed image. The objective in developing this model is to allow second-order thematic information about the scene to be inferred from an analysis of these properties and relations. The paper briefly outlines the application of this model and an associated set of analytical techniques to infer land use from an initial land cover map derived from a digital remotely-sensed image.

ISSN:1365-8816    

DOI:10.1080/136588197242194

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Current trends in modern organizations towards flatter structures and the involvement of many stakeholder groups in solving spatial decision problems have created a need for information technology capable of supporting collaborative spatial decision-making. Such information technology has developed in recent years for the computerized support of group decision-making aimed at solving business problems, e.g., market strategies, corporate planning, product development, and others. Similar information technology to support group decisionmaking aimed at solving spatial decision problems, e.g., site selection, choice of environmental and economic strategies, and urban/regional development, are now beginning to appear in the research literature. GIS, often designed for spatial decision support, have lacked a capability to collate interests and interactions to support collaborative spatial decision-making. As a step towards addressing this void, we present a spatial decision support system for groups (SDSS-G) called Spatial Group Choice. A spatial problem focusing on prioritizing habitat site development is used as a backdrop to present the design and development issues. We discuss the technical and social-oriented design guidelines adopted for the development of Spatial Group Choice using a framework that characterizes meetings in terms of spatial-temporal dimensionality. We then describe the design and implementation of Spatial Group Choice, including a 'tour' of the software, using a habitat restoration decision problem. We conclude with issues unresolved and prospects for future development.

ISSN:1365-8816    

DOI:10.1080/136588197242202

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

ISSN:1365-8816    

DOI:10.1080/136588197242211

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

ISSN:1365-8816    

DOI:10.1080/136588197242220

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor