1、PDF外文：http:/ 附录 1 外文文献原文 The role of the map in a Web-GIS environment Menno-Jan Kraak International Institute of Geoinformation Science and Earth Observation, Department of GeoInformation Processing, PO Box 6, 7500 AA Enschede, The Netherlands(e-mail: kraakitc.nl) Abstract. The Wor
2、ld Wide Web has changed the perspective on the role that maps can play. Their traditional function remains, e.g. to represent an abstraction of a selected part of reality to offer insight into geospatial patterns and relations. Additionally the map can be an important part of a search engine, especi
3、ally in the context of geospatial data infrastructure. Maps can also function as an interface to other geographic and nongeographic information on the Web. The question What are the implications of this expanding role of maps for a WebGIS environment? is addressed in this paper. 1 Introduction Maps
4、are recognised in their capacity to offer an overview of and insight into spatial patterns and relations. Maps can guide us from A to B, show the structure of the landscape, display the changes in population distributions, or show future urban plans. Maps do this because they represent abstractions
5、and selections of reality. If well designed, the meaning of their symbology will give the user a link to a part of reality. Geographical Information Systems (GIS) are characterised by the ability to integrate geospatial data from a wide variety of sources. The functionalit
6、y of such systems allows different kinds of spatial analysis operations. The nature of these operations is often based on applications models, the current disciplinary approach to the problem at hand. Obviously, maps play an important role in GIS. Not only do they present the nal results of the spat
7、ial analysis but they are also critical during the whole iterative process of geospatial data handling. The popularity of GIS has had a great impact onmaps. Many maps have been created and used, but during the beginning of the GIS era map quality was not always acceptable. This was partly due to the
8、 fact that not all people involved in GIS-mapmaking were skilled in this process, and partly due to the limited resolution of screens and plotters. The rise of the Internet, and in particular the World Wide Web, was another stimulant to map making and map use. However, the Web has also brought
9、 specic changes and opportunities due to the characteristics of this medium. These changes are related to the look and function of maps and their dissemination. As such, the use of the Web has had much wider implications than the rise of GIS. Today, millions of maps are being made and used by an aud
10、ience that earlier on would not necessarily have thought of creating maps themselves. Authorities that used GIS to run, for instance, a municipality or a state saw opportunities to use the Web to improve working processes and increase their service level to the public. Via the Web they started to of
11、fer their own employees better access to the wealth of geospatial data available, and at the same time they began to offer citizens more insight and aide them for public participation in local affairs. In the above process WebGIS will potentially play a prominent role since it offers GIS functionali
12、ty in a Web environment. However, currently most WebGIS application in use is limited to (interactive) mapping applications. This paper will discuss the role of the map in a WebGIS environment. To be able to understand this role, the next section will sketch the latest relevant developments in
13、 mapping, followed by a discussion of the role of maps, and conclude with comments on suggested future trends. 2 Trends in mapping The opportunities offered by hard- and software developments have changed the scientic and societal needs for geo-referenced data and, as such, for maps. New media such
14、as the Web not only allow for dynamic presentation but also for user interaction. Users expect immediate and real-time access to the data, which have become abundant in many sectors of the geoinformation world. This abundance of data, seen as a paradise by some sectors, is a major problem in other s
15、ectors. We lack the tools for user-friendly queries and retrieval when studying the massive amount of data for instance produced by sensors, now available via the Web (Cartwright et al. 1999； Kraak and Brown 2000； Peterson 2001). Maps are no longer just a medium to display nal results. Maps are used
16、 anywhere in the geospatial data handling process. Additionally, technological developments have brought mapping closer to other disciplines, which have inuenced the approach to mapping. Interaction and dynamics became important keywords. In the 1990s, developments around scientic visualization (McC
17、ormick et al. 1987) have given the word visualization an enhanced meaning. These have linked visualization to more specic ways in which modern computer technology facilitates the process of making data visible in real time in order to strengthen knowledge. The relations between mapping and GIS on th
18、e one hand, and scientic visualization on the other have been discussed in depth by (Hearnshaw and Unwin 1994； Taylor 1994； MacEachren and Taylor 1994). In addition to scientic visualization, which deals mainly with medical imaging, process model visualization, and molecular chemistry, another branc
19、h of visualization that inuenced mapping can be recognized. This is called information visualization (Card et al. 1999), and focuses on visualization of non-numerical information. In this eld we see the map used as metaphor to access data. Other disciplines 84 Menno-Jan Kraakhaving had inuence on th
20、e map are image analysis, exploratory data analysis (EDA), and of course methodological developments in GIS and cartography not to be forgotten. The above developments in scientic visualisation stimulated (DiBiase 1990) to dene a model for map-based scientic visualisation. It covers both the communi
21、cation and thinking functions of the map. Communication is described as public visual communication since it concerns maps aimed at a wide audience. Thinking is dened as private visual thinking because it is often an individual playing with the geospatial data to determine its signicance. On a more detailed level, different visualisation stages can be recognised, each requiring a different strategy from the perspective of map use. This ranges from presentation to exploration. The rst ts into the traditional realm of cartography, where the cartographer works on
