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1.
Abstract

An intelligent expert system shell for the development of knowledge-based geographical information systems (GIS) is examined in this two-part article. Basic concepts and the overall architecture of the shell are discussed in the present part. Fuzzy logic and expert systems technology are demonstrated to be appropriate methods for approximating human reasoning and enhancing the level of intelligence in GIS. The shell can be employed as an effective and efficient tool for developing knowledge-based GIS.  相似文献   

2.
Abstract

This paper describes a framework for the role of geographical information systems (GIS) in the monitoring and management of hazardous waste sites. Compilation of required information, incorporation of existing strategies for waste monitoring, analysis of these data in a GIS environment and the integration of computerized models for transport processes are discussed. Examples for the analysis of spatial data using techniques of cartographic overlay and the implementation of geo-statistical methods on monitoring data are provided from work in progress by the authors. These examples are set in the context of developing a fully integrated monitoring and management system utilizing GIS technology.  相似文献   

3.
Why not SQL!     
Abstract

The application of traditional database query languages, primarily the Structured Query Language SQL, for geographical information systems (GIS) and other non–standard database applications has been tried unsuccessfully; therefore, several extensions to the relational database query language SQL have been proposed to serve as a spatial query language. It is argued that the SQL framework is inappropriate for an interactive query language for a GIS and an extended SQL is at best a short term solution. Any spatial SQL dialect has a number of serious deficiencies, particularly the patches to incorporate the necessary spatial concepts into SQL.  相似文献   

4.
Abstract

Remotely-sensed data constitute a major potential source of input to geographical information systems (GIS)However, these data often have a relatively poor classification accuracy compared with that of the cartographic data from maps with which they may be combined in the course of GIS analysis. The possibility exists of using data sets (in the form of digital maps) resident within a GIS in order to improve this accuracy, before the classified image is incorporated into the GIS. Results are discussed from a British Alvey Information Technology project to develop a system for the knowledge-based segmentation and classification of remotely-sensed terrain images, in which the knowledge contained in digital map  相似文献   

5.
Abstract

In state-of-the-art GIS, geographical features are represented as geometric objects with associated topological relations and classification attributes. Semantic relations and intrinsic interrelations of the features themselves are generally neglected. In this paper, a feature-based model that enhances the representation of geographical features is described. Features, as the fundamental depiction of geographical phenomena, encompass both real world entities and digital representation. A feature-based object incorporates both topological relations among geometric elements and non-topological (semantic) relations among features. The development of an object-oriented prototype feature-based GIS that supports relations between feature attributes and feature classes is described. Object-oriented concepts such as class inheritance and polymorphism facilitate the development of feature-based GTS.  相似文献   

6.
Abstract

A raster/quadtree geographical information system (GIS) was established For a 932 ha natural area in central Missouri. The GIS contained map layers depicting vegetative cover from 1939 to 1982, soils, topographic aspect and distance from a forest seed source. Discriminant function analysis was used to quantify and describe ecological succession on the area during this period. The calibration of discriminant functions is discussed, as are the statistical and spatial validations of the model. It was concluded that this approach provides a useful technique to examine long-term temporal phenomena in a spatial context.  相似文献   

7.
Abstract

Recent developments in geographical information systems have drawn upon concepts of fuzzy set theory and multi-criteria methodology. In this paper we argue that there is a method, Saaty’s Analytic Hierarchy Process (AHP), that is compatible with both these research directions. The contributions of the AHP are highlighted in the light of recent developments in GIS, with particular attention to the concept of fuzzy set theory. An example of a GIS application is provided to show how the AHP can deal operationally with fuzziness, factor diversity and complexity in problems of land evaluation involving the location of a public facility.  相似文献   

8.
A Pedagogic Framework to Link GIS to the Intellectual Core of Geography   总被引：4，自引：3，他引：1  
《The Journal of geography》2012,111(6):578-591
Abstract

This paper aims to develop a new pedagogic framework for teaching GIS at the college and university level using Berry's geographic matrix. By synthesizing different schools of thought, this paper argues that GIS education essentially involves two aspects—how to teach about GIS and how to teach with GIS. Berry's geographic matrix can be used to tie these dual aspects of GIS education together neatly. As an abstract representation of geographical phenomena, the geographic matrix embeds all three entities of GIS—location, attribute, time—and thus can help GIS instructors teach about GIS. As a synthesis of geographical approaches, the geographic matrix can assist GIS instructors teach with GIS. This paper demonstrates that GIS is actually an implementation of Berry's geographic matrix. Furthermore, the 10 approaches to geographical analysis, originally proposed by Berry for the geographic matrix, can be executed routinely in a GIS environment. By incorporating Berry's geographic matrix into GIS education, teachers can enable students to surpass technical issues and to appreciate the conceptual and functional linkages between GIS and geography's intellectual core.  相似文献   

9.
Abstract

With the rapid growth in the use of geographical information systems (GIS) has come an acute shortage of skills. Although traditional techniques of education and training based on courses at various levels are being widely exploited, there is special potential in GIS for the use of demonstrators and tutors. Such computer aided learning (CAL) tools offer an effective way of putting across the graphical concepts which are vital to GIS as well as offering an attractive form of self-paced study. This paper discusses the contribution of CAL tools to GIS education and offers a short history of the techniques. A case study of the development of the Geographical Information Systems Tutor (GISTutor) is also used to illustrate the educational and technical issues behind the creation and use of such a tool.  相似文献   

10.
Abstract

The planning and establishment of a geographical information system (GIS) relates to its context and intended use. GIS are a specialized type of information system, typically dealing with spatial data. This paper explores the environment of an envisaged GIS; the information utilization system and the wider object system. The planning and design of a GIS go beyond technical issues; they also have to take behavioural and organizational aspects of the utilization of information into account and contribute to a process of organizational development The paper is in two parts. The first (§ 2) explores salient aspects in the planning and design process, the second ( § 3) suggests some guidance in this task. The suggested approach of strategic choice in planning and establishing a GIS is designed to cope with the prevailing uncertainties in this planning process. It distinguishes between those decisions which have to be taken at once and choices which may be left open for the future.  相似文献   

11.
Abstract

Many spatial decision-making problems, such as site selection or land use allocation require the decision-maker to consider the impacts of choice-alternatives along multiple dimensions in order to choose the best alternative. The decision-making process, involving policy priorities, trade-offs, and uncertainties, can be aided by Multiple Criteria Decision making (MCDM) methods. This paper presents a framework for integrating geographical information systems (GIS) and MCDM methods. In this framework the MCDM methods are classified and matched with choice heuristics used by the decision-makers in the presence of competing alternatives and multiple evaluation criteria. Two strategies for integrating GIS with MCDM are proposed. The first strategy suggests linking GIS and MCDM techniques using a file exchange mechanism. The second strategy suggests integrating GIS and MCDM functions using a common database. The paper presents the implementation of the first strategy using PC-ARC/INFO, a file exchange module, and four different MCDM computer programs.  相似文献   

12.
Abstract

A neglected aspect of facility location problems is the geometric representation of the facilities sited and clients served. Point objects represent these entities in most facility location problems. This can cause solution error and limit the range of potential solutions. The increasing capabilities of geographical information systems (GIS) to represent, store and manipulate spatial entities provides a substantial but unrealized potential for more sophisticated geometric representation in facility location problems. This paper provides a framework for realizing this potential. Specifically, this paper: (i) synthesizes existing formulations; (ii) develops a unified mathematical framework; (iii) identifies feasible computational strategies that can be implemented within a GIS framework, and; (iv) discusses potential GIS-based solution algorithms.  相似文献   

13.
Abstract

Implementation of geographical information systems (GIS) involves a substantial commitment of resources by the sponsoring agency. Economic evaluation of the proposed GIS is an important step in the implementation process. This article discusses the traditional benefit cost analysis and suggests alternative approaches which may prove useful in situations where the benefit cost model may not be appropriate. A case study of an actual implementation of a GIS which illustrates the approaches discussed is also presented.  相似文献   

14.
《The Journal of geography》2012,111(6):245-252
Abstract

Geographic information systems (GIS) is a fairly new and evolving curriculum area within geography and other disciplines at colleges and universities in the United States. The challenge of teaching underlying concepts of GIS functionality, the details of computer operation and software interfaces, as well as the contexts of various applications can be a difficult one. At Indiana University of Pennsylvania, a teaching strategy—Client-Life Cycle GIS Project Learning—has been introduced in which students in an upper level GIS course work with local organizations, faculty from other university departments, and governmental entities. This allows students with some GIS background to work with real clients; utilize and operationalize the concepts of the GIS Project Life Cycle; make the connection between data development, analysis, and applications development; provide expertise and needed data to local organizations; and see the utility and impact of their work. A group pilot project from the spring semester of 1998 is discussed to illustrate how students responded to this method of teaching GIS.  相似文献   

15.
The availability of continental and global-scale spatio-temporal geographical data sets and the requirement to efficiently process, analyse and manage them led to the development of the temporally enabled Geographic Resources Analysis Support System (GRASS GIS). We present the temporal framework that extends GRASS GIS with spatio-temporal capabilities. The framework provides comprehensive functionality to implement a full-featured temporal geographic information system (GIS) based on a combined field and object-based approach. A significantly improved snapshot approach is used to manage spatial fields of raster, three-dimensional raster and vector type in time. The resulting timestamped spatial fields are organised in spatio-temporal fields referred to as space-time data sets. Both types of fields are handled as objects in our framework. The spatio-temporal extent of the objects and related metadata is stored in relational databases, thus providing additional functionalities to perform SQL-based analysis. We present our combined field and object-based approach in detail and show the management, analysis and processing of spatio-temporal data sets with complex spatio-temporal topologies. A key feature is the hierarchical processing of spatio-temporal data ranging from topological analysis of spatio-temporal fields over boolean operations on spatio-temporal extents, to single pixel, voxel and vector feature access. The linear scalability of our approach is demonstrated by handling up to 1,000,000 raster layers in a single space-time data set. We provide several code examples to show the capabilities of the GRASS GIS Temporal Framework and present the spatio-temporal intersection of trajectory data which demonstrates the object-based ability of our framework.  相似文献   

16.
杜云艳  易嘉伟  薛存金  千家乐  裴韬 《地理学报》2021,76(11):2853-2866
地理事件作为描述地理过程的基本单元,逐渐成为地理信息科学（GIS）核心研究内容。由于受人类活动数据获取限制,GIS对地理事件的建模和分析主要关注事件所引起的地理空间要素变化及要素之间的相互影响与作用机制。然而,近年来随着基于位置服务数据（LBS）爆炸式的增长和人类活动大数据定量刻画手段的快速发展,地理事件对人类活动的影响以及公众对地理事件的网络参与度都引起了多个领域的广泛关注,对地理事件的时空认知、建模方法和分析框架提出了巨大的挑战。对此,本文首先深入分析了大数据时代地理事件的概念与分类体系;其次,基于地理事件的时空语义给出了基于图模型的事件数据建模,建立了事件本体及其次生或级联事件的“节点—边”表达结构,开展了事件自身时空演化及其前“因”后“果”的形式化描述;第三,从时空数据分析与挖掘的角度,给出了大数据时代地理事件建模与分析的整体框架,拟突破传统“地理实体空间”事件探测与分析方法的局限性,融合“虚拟空间”事件发现与传播模拟思路,实现多源地理大数据支撑下的面向地理事件的人类活动多尺度时空响应与区域差异分析;最后,本文以城市暴雨事件为例诠释了本文所提出的地理事件建模与分析方法,从城市和城市内部两个尺度进行了暴雨事件与人类活动的一致性响应及区域差异分析,得到了明确的结论,验证了前文分析框架的可行性与实用性。  相似文献   

17.
Abstract

The Institute of Terrestrial Ecology (ITE) Digital Cartographic Service provides a range of services to the scientists of ITE (and others) including various techniques within the field of geographical information systems (GIS). This paper discusses work of this type as it is applied to specific ITE projects. The emphasis is very much on GIS applications to ‘real ecological science’ such as the ‘acid water’ problem and the change of forest areas into heathland. Some comments are made on fundamental GIS techniques, their use and limitations. At ITE, GIS applications are growing out of an existing use of digital mapping and remote sensing technologies; they have not purchased a GIS system ‘off the shelf.’  相似文献   

18.
Abstract

A great deal of recent work in computer science applies itself to temporal database design. Designers of geographical information systems (GIS) can build on this work to create a temporal GIS capability to trace geographical change and understand geographical processes. This paper reviews temporal research in information processing, contrasts various proposed temporal database designs and summarizes the problems of adapting it to GIS requirements.  相似文献   

19.
信息和通信技术(ICTs)对日常生活产生重要影响,而时间地理学及时应对了日常生活的数字化转向。论文梳理了日常生活数字化转向的基本特征,包括破碎化、多任务与时空替代等方面。相关实证研究试图回答ICTs是否以及如何改变日常生活,但是忽略了对其内在机制的阐释。时间地理学应对日常生活数字化转向的最新研究包括理论扩展与可视化及分析工具发展等方面,这为理解与刻画日常生活的数字化转向提供了新的理论框架与有效工具。研究发现,首先,经典时间地理学的理论和概念可扩展应用于虚拟空间中的行为。时空间去耦合是日常生活数字化转向的内在机制。其次,基于GIS开发了物质—虚拟混合空间行为的可视化和测度方法。最后,新时间地理学对日常活动复杂情境的分析直观揭示了日常生活数字化转向的时空去耦合机制与破碎化、多任务、时空替代等基本特征,并提出前后台活动、ICT介导的活动束、ICT介导的秩序口袋等理解移动ICTs影响下日常活动转型的创新概念。最后,以时间地理学为基础,提出以实虚活动系统为核心的日常生活数字化转向研究框架,并从数字生活、智慧社会和安全城市等方面讨论未来研究议题。  相似文献   

20.
Abstract

The field of geographical information systems (GIS) is reviewed from the viewpoint of spatial analysis which is the key component of the familiar four-part model of input, storage, analysis and output Input is constrained by the limits of manual methods and problems of ambiguity in scanning. The potential for developments in output is seen to be limited to the query mode of GIS operation, and to depend on abandoning the cartographic model. Discussion of storage methods is organized around the raster versus vector debate and the need to represent two spatial dimensions in one. A taxonomy of GIS spatial analysis operations is presented together with a generic data model. Prospects for implementation are discussed and seen to depend on appropriate scales of organization in national and international academic research.  相似文献   

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