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Building National GIS Infrastructures Using the Geography NetworkBy Jerry Johnson, Esri
The development of GIS databases over the last decade has led to a collection of powerful islands of data within nations and states. Each scientific discipline often contains dozens or hundreds of diverse data sets at national and local level institutions. These unconnected GIS databases have a wealth of information collected at different scales and projections and with different database schemas, and may, in many cases, represent the same topic of study or interest. Regardless of the source or size, they all reflect a national investment in software, hardware training, and expertise, which needs to be managed in such a way to make the most use of past and future investments for the development of a country.
At the national level, development decisions are becoming increasingly dependent on understanding a host of diverse but interconnected issues such as environmental, urban, agricultural, and other developmental issues. While the use of GIS in national policy-making has been used increasingly in the United States over the last five years, the emergence of national GIS efforts internationally is accelerating. Increasingly, national governments are accepting spatial databases as an important component of their national information infrastructure, for they assist in the understanding of the complex systems they must understand in order to pro-gress national development. The benefit to the GIS community of national recognition elevates the science to a whole new level of importance, which will have profound implications in many areas.
Above right: The Internet provides a framework for future national data sharing and planning across agencies.
Some of the initial priorities of a national GIS effort are the creation of a national framework database, the creation of a clearinghouse and distribution network for GIS data, and the incorporation of international standards. The national framework, or web, upon which a national GIS infrastructure is built, must tackle many development hurdles. However, recent developments in the GIS and IT industry have helped to lay the groundwork upon which a network can be built.
The Geography Network and ArcGIS
Implementers can greatly benefit from the technology used and concepts developed for the Esri Geography Network. The Geography Network is a collaborative and multiparticipant system for publishing, sharing, and using digital geographic information on the Internet. The Geography Network can be thought of as a large online library of distributed GIS information available to everyone. It has been designed to adhere to open standards for the dissemination and sharing of data and services. Professional users can connect to the Geography Network and directly use the data and application services provided by other participants.
Previous to the Geography Network and ArcGIS, the concept of a national GIS was taking vast GIS databases and centralizing them for later distribution. This led sometimes to insurmountable problems, among which was data standardization across large data holdings of many organizations and the need for high-speed dedicated telephone lines. Very rarely do we find a pre-planned national GIS effort. So what has changed?
The Geography Network and the ArcGIS 8.1 product family have introduced capabilities that make national integrated GIS more achievable. With the Internet, data no longer has to be centralized. Data "registration" within a clearinghouse means data can be local. This alleviates many of the data sharing issues that can exist among agencies. With the Internet enabling ArcGIS 8.1 desktop clients (ArcInfo, ArcInfo Editor, ArcView GIS, and ArcExplorer), raster and vector data can now be dynamically streamed across the Web from an ArcIMS server. Hence, extensive data handling and analysis capabilities can be attained using the Internet. The ability to share metadata through the Internet can provide information from which reprojection on-the-fly allows different data sets to be brought together at the desktop. Also, the development of spatial database technology has contributed to moving large spatial databases to the Internet.
Over the last few years different standards have arisen to dominate the IT industry and now the GIS industry. XML for sharing metadata over the Internet, Java, COM, and evolving OpenGIS Consortium standards all have been introduced into the Geography Network and ArcGIS 8.1 to deliver the most open system framework for developing a national GIS infrastructure. One can see in the future the linking of extensively developed national GIS infrastructure components to the existing Geography Network to provide an even more integrated world.
The component pieces of national geography networks are already being built in the form of applications-specific national databases. If we look at Korea's national GIS efforts, for example, progress is being made in the development of public utilization systems (see "Korea National GIS Initiative"). Those under development are the Land Management System (LMS), the Soil Resource Information System (SRIS), the Forest Management System (FMS), the Geological Resources Management System (GRMS), and the Underground Utility Management System. The Korea national GIS effort has two important objectives for the future. The first is to use GIS in all public and private disciplines within the next five years, and second is to integrate these disciplines as components of an Internet-based national GIS. The development of national systems, in addition to the importance they hold in themselves, is also helping to consolidate large data holdings making the development of a national framework more efficient.
For more information, contact Jerry Johnson, Esri (e-mail: email@example.com).