To the National Map and Beyond
Kelmelis, John, Cartography and Geographic Information Science
people have relied on maps and geographic information for survival, economic development, and recreation for millennia. One can imagine prehistoric people scratching lines into the mud to direct others to better hunting grounds, describe the relationships of caves to rivers and highly productive food sources, outline dangerous locations, or emphasize the benefits and safety of a prized place of respite. As society developed in complexity through the various levels of band, tribe, chiefdom, and state (Diamond 2001), and beyond to multistate structures and alliances and global enterprises, the need for maps and geographic information continued to increase. The evolution of societies is intertwined with the evolution of technology; major transitions were facilitated by harnessing fire, taming animals, developing metallurgy, the invention of laborsaving devices, and the proliferation of information. In our times, the sophisticated electronically linked nations and multistate societies depend on a highly accurate, readily accessible, and current information infrastructure.
Because a great portion of society's economy depends on geographic information (Bernknopf et al. 1993; Bhagwat and Viju 2000; Kelmelis 2001; NAPA 1998; Oxford Economic Research Associates 1999), maps are a critical part of this information infrastructure. Just as people still sketch maps in the mud to communicate geospatial information, maps printed on paper or other portable, durable material will always be needed. However, the digital age has provided new opportunities for the production, distribution, and use of geospatial information.
In the United States, the authority to produce topographic surveys of the national lands rests in the legislation that established the U.S. Geological Survey (USGS) in 1879 (USGS 1986). Ten years following this legislation, specific language on topographic surveys was included in the Appropriations Act of 1889, and, in 1897, the USGS was authorized to distribute maps and atlases in Public Resolution 13 of the 54th Congress. The USGS conducted cooperative (joint) funded topographic mapping projects in partnership with States and municipalities during the 1880s, which was recognized in Public Law 100 of the 70th Congress in 1928.
The U.S. Geological Survey produced topographic maps of the United States at various scales throughout its history. The current standard topographic map is produced at the 1:24,000-scale and l:25,000-scale for the conterminous US, Hawaii, and the Virgin Islands; at the l:30,000-scale for Puerto Rico; and at the 1:25,000-scale and 1: 62,500-scale for Alaska. All the United States, except parts of Alaska, has been mapped at the standard scales. Revision has taken place for many topographic map quadrangles in the areas of greatest land surface change. However, the average age of standard topographic maps for the United States is 23 years (Ryan 2002).
This paper discusses the transition from analog to digital maps and the concept of the National Digital Cartographic Database (NDCDB); separating the topographic map into individual theme-based data layers and their importance to the National Spatial Data Infrastructure (NSDI); the recombination of these data layers into a spatial data framework, with enhanced local data, monitoring, statistical descriptions, scientific assessments, analyses, and application capabilities to form The National Map (TNM). This paper also provides a vision for USGS geography and other scientific disciplines that goes beyond the NSDI and The National Map.
Transition from Analog to Digital Maps
During the mid- and late 1970s, the U.S. Geological Survey established projects to develop digital line graphs (DLG) and digital elevation models. The long-term vision was for a number of theme-based national coverages of digital cartographic data that would be used to improve the cartographic production process and other analytical applications. …