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FUTURE PARTNERSHIPS AND THE EVOLUTION OF NSDI ACTIVITIES 44 contingent upon demonstrating achievement of the four assessment criteria and continued improvement over time. Other incentives could include access to NSDI software tools, applications software, training materials, etc. DATA ACCESS, USE, AND OTHER FRAMEWORK ISSUES In addition to the core goal of populating the Framework, several other critical issues must be addressed in order for the NSDI to be a success, especially in regard to the broader objectives of improving decision making through increasing the effective use of geospatial data at all levels of government, by citizens, and in the private sector. As with Framework data production, partnership programs are needed to address these issues effectively, since both the definition of potential solutions and the implementation of the solutions need to occur in the geospatial community at large. ⢠Data integration (vertical and horizontal). If the enormous potential benefits of the NSDI are to be realized, datasets produced by different organizations, covering different themes and geographic areas, and at different scales, must be used in conjunction with each other, as well as with non- Framework datasets. While the focus on transfer standards and metadata standards has been a necessary step in realizing true integration, it is now necessary to use the standards to actually achieve integration. Vertical integration ensures that data elements from disparate themes over the same geographic area demonstrate logical and geometric consistency. This is difficult enough to achieve when integrating data of the same structural type (e.g., vector hydrographic data and vector transportation data), but becomes even more problematic when integrating disparate types (e.g., raster orthoimagery, matrix- based terrain elevation data, and vector data). Nevertheless, even though these themes may be produced by different organizations, they must be technically compatible in order for the full benefits to be realized. A critical component of this type of integration will be the acceptance of standards that are being developed by the FGDC subcommittees. For example, the Ground Transportation Subcommitteeâs proposed standard on transportation features provides a model for different
FUTURE PARTNERSHIPS AND THE EVOLUTION OF NSDI ACTIVITIES 45 organizations to refer to the same road segment and assign attributes that meet their specific needs. Vertical integration issues can be addressed through several approaches. First, at the time of collection or production, steps can be taken to help maximize consistency across themes. Given the âground truthâ of orthophotography (assuming accurate positional control, sufficient resolution, etc.), production systems that incorporate this imagery into the process (e.g., as a backdrop if not for actual extraction of features) may ensure a level of consistency and accuracy across themes. Similarly, the collection of elevation models utilizing hydrographic information not only improves the accuracy of the terrain data but also helps ensure consistency between these two layers. Thus, data production methodologies can help mitigate the vertical integration problem. Once data have been collected, tools, both automated and interactive, can be used for after-the-fact data accuracy and consistency checking and clean-up. Again, the development and application of these tools can improve integration. Finally, at the user end of the spectrum, that is, in applications, analytical procedures, visualization tools, etc., smart software can deal with potential integration problems and still allow for appropriate use of the various data themes together. For example, inconsistencies or other problems may dictate that it would not be appropriate to combine two themes in an analytical overlay fashion (e.g., point-in-polygon or polygon overlay calculation), even though visual integration at a particular scale is perfectly legitimate. The Web Mapping Testbed of the Open GIS Consortium (OGC, 2001) addresses this issue directly, and has already demonstrated substantial success. Horizontal integration refers to the simultaneous use of datasets across collection or jurisdictional boundaries. This is key, for example, in dealing with issues on a regional (e.g., river basin or watershed) basis. The logical subdivisions fall into three administrative levels: regional, state, and national. The level of responsibility and authority that resides at the state level varies considerably from state to state. For example, the Texas Natural Resources Information System provides public domain statewide coverage of a number of the framework datasets at a scale of 1:24,000 and quarter quad digital orthophotographs. Other states, such as
FUTURE PARTNERSHIPS AND THE EVOLUTION OF NSDI ACTIVITIES 46 Tennessee, have made a major commitment to providing high resolution (1:48,000 and 1:1200) framework data and tax parcels on a statewide basis. The Tennessee state government is providing 75 percent of the $30 million for the project (ESRI, 2001b). Clearly, such a state level commitment will greatly facilitate horizontal integration. As with vertical integration, the problem can be addressed at each stage of the geospatial data collection, production, and use spectrum. To the extent that national-level base data, even at smaller scales than optimal, can be used to identify tie points at the boundaries between data coverage areas, some inconsistency can be avoided. Following data collection, software for checking the consistency of data across collection boundaries can be used to detect inconsistencies and either resolve them in some automated fashion or flag them for manual clean-up. Finally, at the data use or application stage, appropriate use of data across collection boundaries can be accomplished, even in the presence of anomalies such as gaps, attribute changes, and other inconsistencies. Thus, to deal with the integration problem, the NSDI and future partnerships should address the issue by encouraging integrative actions at each stage in the geospatial data process. This may include the development of procedures, processes, software tools, standards, guides, and other aids. ⢠Data use and applications. Clearly, the true payoff of the NSDI will be closely tied to those geospatial data-based applications that make use of Framework and other data to address specific problems or issues facing governments, companies, and NGOs. In the next stage of the NSDI partnership program, the development and diffusion of geospatial applications will be critical to the perceived success of the entire effort. Applications of geospatial data in a particular domain involve the integration of domain-specific data with Framework data, mapping, and visualization of the data, geometric processing, spatial search and retrieval, tabulations of summary data, and incorporation of the data into analytical or predictive models. The ultimate objective of the utilization of geospatial data and technologies is to promote and enhance information-based decision making. There is widespread recognition that spatial data are the core of a new level of services to the citizens. Taxpayers have similar expectations from their local governments as
FUTURE PARTNERSHIPS AND THE EVOLUTION OF NSDI ACTIVITIES 47 they do for other information-based services provided by their banks, travel agencies, bookstores etc. These E-government solutions require considerable innovation to bring a high level of web-based services to a relatively unsophisticated user community. The University Consortium for Geographic Information Sciences (UCGIS) presented a good overview of critical application domains (UCGIS, 2000b). The domain areas include: 1. crime analysis, 2. emergency preparedness and response, 3. transportation planning and monitoring, 4. public health and human services, 5. urban and regional planning, 6. water resources, and 7. involving the public. This list could easily be expanded to include important issues such as environmental protection, equitable tax assessment, school zoning, bus routing, hazards and risk assessment, and growth management. One of the great benefits of sharing spatial data occurs when multiple uses are realized that extend beyond the original need. The Census TIGER (Topologically Integrated Geographic Encoding and Referencing system) line files are the primary example of this. The MSC has argued that by âthrowing the goodies over the fence,â the Census Bureau essentially created new markets and expanded the application domains for GIS practitioners. An important consideration is whether greater cooperation could result in better data with additional attributes or improved spatial resolution for essentially the same cost. The NSDI and associated partnerships should develop application guides based on successful projects that have used geospatial data and tools to address these issues. Ultimately, these guides would be complete âhow-toâ cookbooks that would identify the Framework data, non-Framework and domain-specific data, and the application software tools that are available, where to get them, and how to use them. To the extent that commercial or public-domain software or data exist to address these domains, the guides would point to those resources. In the case where the needed resources do
