National Mapping Program Mission The primary mission of the T National Mapping Division is to provide accurate and up-to-date basic cartographic information for the United States in forms that can be readily applied to present-day problems. Maps, aerial photographs, satellite images, digital data, and geodetic control information represent some of the cartographic products available. Topographic maps at various scales, which illustrate detailed and precisely referenced information about natural and manmade features on the Earth's surface, continue to be important products. These maps provide basic cartographic information that is needed by most Federal, State, and local government agencies in dealing with key issues ranging from satisfying energy demands to conserving natural resources, from identifying environmental problems to developing acceptable solutions, and from locating commercial facilities to designing public works. In addition to maps, cartographic data in computer-readable form are becoming increasingly important. These data are used in computer-based resource and geographic information systems to evaluate alternative management plans and to study the effects of different policies. Highlights Mapping Modernization By Eugene C. Napier, Ernest B. Brunson, and K. Lea Ginnodo When the U.S. Geological Survey was established in 1879, topographic mapping was conducted as an adjunct to geologic studies. Soon, topographic maps were recognized as having intrinsic value as well as value for many other applications. From this beginning, the concept of preparing standard topographic maps for multipurpose use was conceived, and the first standard quadrangle map was completed in 1881. Since that time, the USGS's topographic mapping program has undergone several transitions as users' needs for more detailed map information increased and as mapping procedures and technology evolved. The current transition began in 1979 when the USGS formally initiated the Digital Cartography Program. The widespread use of computers and associated technology has generated new and increasing demands for map information in computer-compatible form. Since 1979, user requirements for accurate and current cartographic data in both digital and graphic forms have accelerated beyond the capacity of the National Mapping Division to produce them. ...The USGS has undertaken an extensive mapping modernization effort.... To respond to this increasing demand, the USGS has undertaken an extensive mapping modernization effort that includes major technical and programmatic transitions. The objective of this modernization effort is to develop and implement advanced digital cartographic systems and production procedures in the USGS's cartographic production centers by the mid-1990's. This modernization will make it easier to revise maps more frequently and to prepare and maintain more up-to-date cartographic products. Tasks underway to accomplish this ambitious goal include expanding and improving mass digitizing capabilities; modifying data structures to support increased content and access requirements; developing digital revision capability; developing digital productgeneration capabilities for standard, derivative, and digital products; improving quality control; and supporting advanced spatial analysis and applications. When these tasks are completed and the digital cartographic systems are fully operational in the mid-1990's, the USGS will be able to meet increasing requirements to keep current the Nation's 57,000-plus primary-scale maps (fig. 1). A Primary Mapping Economic Analysis, completed in fiscal year 1989, showed that there are significant economic benefits to computer-based map revision. Further, the analysis showed that the current target of revising maps on a 10-year cycle is conservative and that there would be greater benefits if the revision cycles were shorter. The mapping modernization effort represents a substantial and timely program change in the USGS. It appropriately takes advantage of state-of-the-art mapping technology and will result in a highly responsive digital cartographic production system. Attaining this goal of modernizing the National Mapping Program will enhance the USGS's ability to meet national requirements for up-todate multipurpose cartographic data and map products. The concerns of both scientists and policymakers are now focused on the potential for long-term changes.... Geographic Contributes to Studies of Global Change By Raymond D. Watts The summer of 1988 was hot and dry. Farmers in the northern Great Plains endured massive crop failures, and Washington, D.C., sweltered in the hottest summer since the 1930's. Political attention was focused on concerns about the effects of human alteration of the global environment, including its climate. In congressional testimony, one scientist expressed "99 percent confidence" that the weather of 1988 was attributable to enhanced greenhouse heating of the atmosphere-a result of higher atmospheric carbon dioxide concentrations from the burning of fossil fuels and deforestation. Most scientists, however, would not agree that such a direct connection has been established. In spite of great progress, current understanding of many aspects of climatic behavior remains rudimentary. Today's computer models of climate are just beginning to incorporate realistic oceanic behavior, and their descriptions of land-atmosphere interactions are woefully inadequate. On short time scales (days to weeks), the atmosphere, oceans, and biosphere are relatively independent. On slightly longer time scales (months, seasons, years), the atmosphere, oceans, and biosphere affect each other, but feedbacks are relatively unimportant. On yet longer time scales (years, decades, centuries), all parts of the Earth's environmental system interact and affect each other-but in ways that scientists do not understand qualitatively, much less quan titatively. The concerns of both scientists and policymakers are now focused on the potential for long-term changes that will span decades or centuries and involve the entire, tightly coupled, land-oceanatmosphere global environmental system. The land component participates in global environmental processes in many ways. It is a new challenge to geographers and cartographers to describe and to measure the role that land plays in order to provide quantitative information that is useful in the development of computer models of the global environment. One of the major challenges to scientists who study global change is to identify the relative roles of human and natural processes and the ways that environmental change, once begun, feeds back through natural and human behavior to effect further change. The USGS is undertaking studies of the land relationships indicated by red lines in figure 2. The central question of these studies is how to provide descriptions of land characteristics that will serve Figure 2. Relationships of human activities and natural processes acting on the land, effects of land changes on natural processes and on humans, and feedbacks into further land change. The relationships represented by red lines are to be examined by the National Mapping Division for application to interdisciplinary global studies. the needs of scientists who study global environmental change. Ecologists, meteorologists, atmospheric chemists, and scientists from numerous other fields need information about topography, geology, botanic cover (including seasonal variations), soils and soil development, erosion, and other land characteristics. Global modeling studies require information. different from that needed for local process studies. For geographers, cartographers, and others who build essential data bases, an understanding of resolution and accuracy requirements is a prerequisite for an effective contribution to the interdisciplinary global research program. Computer models of environmental processes are a distillation of current scientific knowledge. They are quantitative by nature and design; they describe, for example, reservoirs, flows, temperatures, and other characteristics numerically. Limitations in computer size and speed force modelers to characterize the land, its features and behavior, in aggregates. The complexity of our immediate neighborhood, which is so familiar, is therefore lost when a regional representation is formed. Few studies have been done on the quantitative validity of such generalization. The National Mapping Division is studying the problems of quantitative scaling of environmental observations and descriptions as part of its effort to develop strategies for observing and describing the land portion of the global environment. The strategy-development efforts are, themselves, interdisciplinary studies done in collaboration with scientists of many agencies, institutions, and disciplines. Once the strategies are developed, the data gathering will also be interdisciplinary, multi-institutional endeavors. The USGS's EROS Data Center is home to a 20-year archive of Landsat images (both digital and film) as well as to millions of scenes of satellite and aerial photographs that provide a unique set of historical environmental observations. The Data Center's activities are expanding considerably in support of interdisciplinary studies of global change. The Data Center will become the long-term archive for data obtained by NASA's Earth Observing System, Eos-set for launch in the mid-1990's. These observa tions and others will provide an enduring resource for scientists who study the function and changes in the global environment. The Digital Topographic Map of the Future By John E. Findley Scientists in many different disciplines, both in government and the private sector, use and depend upon reliable earth science data. Until the mid-1970's, analog data in the form of printed line maps and image products were the sole source of base cartographic data. More recently, base cartographic and other earth science data have been made available in digital or computer-generated form. These data were initially developed for use only by scientists and were typically distributed on 9-track computer tape without supporting software. The user community, therefore, was effectively limited to persons having some background in the earth sciences (particularly a working knowledge of coordinate geometry and transformations), a reasonable level of programming skill or access to programming resources, and access to a mainframe or large minicomputer. Before microcomputers and the development of the geographic information systems industry, these limitations were not significant impediments. Few users possessed the knowledge to effectively use the data, and even fewer had access to adequate computing resources. Today, however, with the phenomenal computing power that is readily available in the microcomputer market at reasonable prices, and the flexible data integration and manipulation software that is available from numerous vendors, the potential user community of earth science data has become enormous. The USGS and other suppliers of digital spatial data need to evolve with the user community and with applicable technology and, accordingly, to provide data in forms compatible with emerging hardware and software systems. Toward this end, the USGS is investigating several novel approaches for providing users with reliable and accurate data on a number of different media. One such approach is an ongoing research effort called the "Digital Topographic Map of the Future," the objective of which is to develop prototype models of advanced digital data sets on CD-ROM (Compact Disk-Read Only Memory) that depict county-based geographic information. This project proposes to test not only a novel medium for data distribution (CD-ROM) but also a novel spatial coverage (county versus the traditional quadrangle base) and a novel marketing approach in which data display and processing software will be packaged with the data. The goal is to develop a distribution package that will permit novice users to create or display custom maps from standard National Mapping Program digital data by using personal computers. The initial test CD-ROM will contain software to allow users to display digital line graph, digital elevation model, Geographic Names Information System data, and orthophotoimages of Arlington County, Va. Large-Scale Image By John E. Findley The USGS is the Federal agency that is responsible for providing much of the spatial information that is used by scientists to review, analyze, and evaluate geographic information. In the past, this spatial information was conveyed primarily by aerial photographs, line maps, data digitized from maps, and standard orthophotoquads. The USGS has developed advanced techniques to produce a new product termed a "digital" orthophotoquad from aerial photographs. To produce these digital orthophotoquads, computer-generated files, created by scanning aerial photographs, are digi tally rectified by using a digital elevation model to remove displacement of features in the photograph due to changes in elevation. The resulting digital orthophotoquad accurately portrays ground distance and the spatial relationships among objects in the image. A major advantage of the digital orthophotoquad is that advanced computer processing, such as image enhancement, data merging, and digital mosaicking, can be applied to improve the interpretability of the photograph, to allow other geographic and cartographic data to be simultaneously considered, and to permit adjacent photographs to be joined into a single larger map. In a pilot project with the Soil Conservation Service, Department of Agriculture, the USGS prepared 140 3.75- by 3.75-minute digital orthophotoquads (quarter-quadrangles) at 1:12,000 scale over Dane County, Wis. Both the scale and the location were selected as being the most useful for a number of potential applications. Samples of corresponding soft-copy products also were produced for this project for evaluation by the Soil Conservation Service. Several additional prototype products are being prepared to determine the usefulness of orthophoto quarter-quadrangles for selected areas, Digital orthophotograph of Black Earth, Wis., created by using advanced computer techniques. |