首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Abstract

Current geographical information systems (GIS) include functions to create cartographic output interactively or automatically. However, none of the systems presently incorporates mechanisms to ensure correct application of graphic functions. Many of today's users of GIS are not trained in the design and production of graphics and may create maps that confuse or mislead map users. Poorly-designed maps may obliterate the patterns in displayed information.

This article investigates ways to improve the quality of GIS graphical displays and increase their effectiveness for decision-making. Alternatives are presented for improving map design in GIS, ranging from non-technical efforts to enhancement of software functionality. Suggestions propose augmenting users' abilities to create maps in an automated environment, using an approach termed amplified intelligence: key decisions default explicitly to users, whose knowledge is amplified by a range of high-level tools to carry out map design operations automatically.  相似文献   

2.
Abstract

Local government is one of the most important groups of users of geographical information systems (GIS). The significant interest amongst users and the varied demands to be made of GIS have stimulated discussion in many countries. This article presents some of the findings of a research project which is currently exploring the impact of GIS on British local government. The discussion examines the results of a comprehensive survey of all 514 local authorities in Great Britain. These findings provide an overview of GIS adoption in relation to type of local authority and geographical location. Particular attention is focused on the type of systems which have been adopted, the take-up of GIS over time, the software and hardware being utilized and the perceived benefits and problems associated with GIS. The results demonstrate that take-up has been most pronounced in the larger authorities, particularly in the southern part of Great Britain, with the most popular combination of equipment being Arc/Info software and workstations. For those authorities presently implementing a GIS, the technology is expected to improve existing capabilities for information processing rather than enhance decision-making or help achieve savings. In seeking these benefits authorities are encountering considerable problems which include basic technical difficulties in getting the equipment to work, data-related issues surrounding the collection, standardization and maintenance of geographical information, and profound organizational considerations associated with the introduction of information technology into complex environments. There is an urgent need for in-depth case studies which evaluate the experiences of users in relation to the vital process of implementation.  相似文献   

3.
Abstract

The combined use of remotely-sensed images and vector GIS data has received considerable interest in recent years. This review article discusses the historical move towards closer integration of remote sensing and GIS technologies and the requirements of integrated software systems to enable remotely-sensed data to be combined with vector datasets for maximum effect. The benefits of integration to users of both GIS and remote sensing for environmental applications are reviewed and some thoughts are given on terminology and future directions in this field.  相似文献   

4.
Abstract

Abstract This paper provides an overview of developments and applications of geographical information systems (GIS) in North America over the past 20 years, together with some indications of lessons learned and prospects for the future. Most developments in this field have been confined to a small number of sectors, including forestry, land registry, transport and facility planning, civil engineering, agriculture and environment, although progress has been variable. The wider use of GIS has been (and will probably continue to be) inhibited by a number of factors, such as lack of digital base mapping, limited digital data, unawareness among potential users and resistance to new technology, coverage of data, assessment of costs and benefits, technological developments affecting GIS and sources of funds for research to political structures, availability of skilled staff, lack of proper advice, the unwisdom of ‘going it alone’ and management problems (which are as important as technical problems, if not more so). A successful programme of GIS depends on a coordination of effort relating to applications, trained personnel, governmental involvement in R. &D. and development of a source of independent advice.  相似文献   

5.
Abstract

This article is an agreed summary of a workshop held in Sheffield between 18-20 March 1991. The focus here is on three of the themes of the workshop: the mutual benefits of closer links between geographical information systems (GIS) and the methods of spatial data analysis (SDA); the specific areas of SDA that should be linked with GIS; how the linkage should be made in practice. Directions for future research are also reviewed. The emphasis throughout is on statistical SDA and principally from the perspective of human rather than physical geography.  相似文献   

6.
《The Journal of geography》2012,111(4):148-157
Abstract

Geographical information systems (GIS) were phased into the geography curriculum of South African schools from 2006–2008 as part of the National Curriculum Statement (NCS) for grades 10–12. Since its introduction, GIS education in schools across the country has been met with a number of challenges including the cost of purchasing the hardware and software required to elucidate the basic concepts of GIS to learners. This article examines the introduction of GIS education in schools in South Africa. The development and distribution of a paper-based GIS educational package for resource-poor schools in the country is also highlighted. Preliminary educator and learner evaluations of the paper-based GIS package are discussed and the broader learning opportunities and benefits associated with flexible teaching mechanisms are examined.  相似文献   

7.
8.
9.
Abstract

This is the first of two papers elaborating a framework for embedding urban models within GIS. This framework is based upon using the display capabilities of GIS as the user interface to the conventional modelling process, beginning with data selection and analysis, moving to model specification and calibration, and thence to prediction. In this paper, we outline how various stages in this process based on purpose-built software outside the system, are accessed and operated through the GIS. We first deal with display based on thematic maps, surfaces, graphs and linked windows, standard to any data from whatever source, be it observations, model estimates or predictions. We then describe how various datasets are selected, how the spatial system can be partitioned or aggregated, and how rudimentary exploratory spatial data analysis enables scatterplots to be associated with thematic maps. We illustrate all these functions and operations using the proprietary GIS ARC-INFO applied to population data at the tract level in the Buffalo region. In the second part of the paper, various residential location models are outlined and the full modelling framework is assembled and demonstrated.  相似文献   

10.
Abstract

Geographical information systems (GIS) provide capabilities for the mapping, management and analysis of cartographic information. Unlike most other disciplines, GIS technology was born from specialized applications. A comprehensive theory relating the various techniques used in these applications is only now emerging. By organizing the set of analytic methods into a mathematical structure, a generalized framework for cartographic modelling is developed. Within this framework, users logically order primitive operators on map variables in a manner analogous to traditional algebra and statistics. This paper describes the fundamental classes of operations used in computer-assisted map analysis. Several of the procedures are demonstrated using a fourth-generation computer language for personal computers.  相似文献   

11.
This article aims to develop a new type of temporal pattern analysis—temporal point pattern analysis (TPPA)—by treating the distribution of activities as a point pattern on a two-dimensional plane using the start time and end time of activities as axes. Geographic information systems (GIS) methods, which are originally used in spatial point pattern analysis in GIS, are introduced to support TPPA. This article presents a case study to understand the temporal patterns of the library visiting activities of university students using a four-week smart card data set in Chengdu City, China. Several methods from GIS are applied, including the measurement of mean centers, kernel density, nearest neighbor distances, and optimized hot spot analysis. Results show that the GIS methods can reveal a lot of information on the temporal pattern of activities, thereby proving the reasonability of the proposed TPPA of activities. Key Words: GIS, human activities, library visiting, smart card data, visualization.  相似文献   

12.
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   

13.
Abstract

An error model for spatial databases is defined here as a stochastic process capable of generating a population of distorted versions of the same pattern of geographical variation. The differences between members of the population represent the uncertainties present in raw or interpreted data, or introduced during processing. Defined in this way, an error model can provide estimates of the uncertainty associated with the products of processing in geographical information systems. A new error model is defined in this paper for categorical data. Its application to soil and land cover maps is discussed in two examples: the measurement of area and the measurement of overlay. Specific details of implementation and use are reviewed. The model provides a powerful basis for visualizing error in area class maps, and for measuring the effects of its propagation through processes of geographical information systems.  相似文献   

14.
Abstract

Abstract Chinese governments have long paid a great deal of attention to the collection of geodata, and existing sources have been further enhanced by technological advances, notably in remote sensing. Progress has also been made with automated cartography. An expert working group has been examining GIS and it is recognized that a system combining both national and regional components is most appropriate for China. Three basic functions are envisaged for such GIS: comprehensive regional analysis, prediction of change and the sharing of data. Such systems must serve the needs of users and, in order to demonstrate potential applications, regional experiments are being undertaken, including examples of urban information systems, river basin information systems and specialized systems (e.g. for tourist and forest resources). In the next few years, the emphasis will be on research and on technological preparation for the adoption of GIS, including the use of an experimental set of geographical grid cells. Chinese scholars are also involved in international collaboration in the study of global problems and propose a cooperative programme for a global geographical information system.  相似文献   

15.
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   

16.
Abstract

Research on time and data models for Geographical Information Systems (GIS) has focused mainly in the representation of temporal geographical entities and implementation of temporal databases. Many temporal GIS database structures have been proposed but most of them just provide principles, not the recipe for the design. Owing to the manipulation of the large quantity of geographical information and the slow response time, few implementations exist. This paper presents a relational method of storing and retrieving spatial and temporal topologies. Two-level state topologies are proposed: a state topology for a set of geographical entities and a state topology for a single geographical entity.

From a temporal perspective, these two-level state topologies may also be viewed as two-level time topologies: a time topology for all geographical entities in a GIS database and a time topology for a single geographical entity. Based on these state and time topologies, a detailed storage approach for historical geographical information is provided.  相似文献   

17.
Abstract

The National Science Foundation will soon establish a National Center devoted to geographical research and education based on geographical information systems (GIS). The Center will be located at a university chosen on the basis of competitive proposals that will be evaluated primarily on the quality of their research agendas. The winning institution will be expected to involve government agencies and private firms in Center operations and programmes, and it will be expected to serve the national GIS community. The Center arose from a suggestion made by a member of the GIS research community. A large-scale database initiative and a Foundation commitment to Science and Technology Centers provided an institutional environment hospitable to the Center. There are similarities and differences in the approach taken toward GIS research, policy and applications in the United Kingdom (UK) and in the United States (US). Those similarities and differences offer promising topics for collaborative research on GIS itself and on GIS as an information technology affecting the discipline of geography. Cross-national UK-US research would be a productive step toward the globalization of GIS and GIS research.  相似文献   

18.
Abstract

Abstract. The growth of the remote sensing field has caused and explosion in the size and complexity of Earth satellite image databases. The explosion of data is already challenging current satellite-based GIS databases. New technologies for information management will be required in the future to maintain these large geographically-oriented systems created by projects such as NASA's Earth Observing System (EOS). This paper presents a technology adapted from the planning/scheduling field in Artificial Intelligence (AI) that promises to automate and facilitate the process of creating and storing satellite images and their associated data products.  相似文献   

19.
Abstract

The City of Scarborough, like many corporations, recently re-evaluated its information technology requirements. The decision was made to model the City's needs in terms of activities and data requirements, concentrating on the Municipal Data Model. First, a two year study was undertaken to understand the business activities of all the disparate components that make up the corporation. This study resulted in individual Information Resource Plans (IRP) for each department. A third year was spent in reconciling the many separate documents and creating a high-level Conceptual Data Model for a Corporate Information System. Of the thirteen broad data groupings, four were assigned to the GIS Group for the design of Detailed Data Models and to populate the resultant databases. The GIS Group, in fact, were to initiate the new Information System for the entire City. The modelling sessions involved hundreds of users from the entire user community in small and large groups, in intensive entity-definition activities, in technical review sessions and in the general examination of context. The detailed models were validated by involving still more users and by testing the model in prototypes, special projects and joint ventures. The GIS Project has demonstrated that data modelling is an effective and realistic method of reflecting the municipality as an enterprise.  相似文献   

20.
Abstract

Although biological diversity has emerged in the 1980s as a major scientific and political issue, efforts at scientific assessment have been hampered by the lack of cohesive sets of data. We describe, in concept, a comprehensive national diversity information system, using geographical information system (GIS) techniques to organize existing data and improve spatial aspects of the assessment. One potential GIS analysis, to identify gaps in the network of nature reserves for California, is discussed in greater detail. By employing an information systems approach, available data can be used more effectively and better management strategies can be formulated.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号