About the Cover.-A geographic information system (CIS) is a computer system capable of assembling, storing, manipulating, and displaying geographically referenced information; that is, data that have been identified according to their locations. Capturing the many types of data available and needed to make effective use of GIS technology is the time-consuming component of GIS work. The U.S. Geological Survey (USGS) is intensively involved in the acquisition of earth science data for use in GIS through its mission-mandated research and investigations. The theme chapter of this Yearbook describes many of the applications that the USGS is employing using GIS technology. In addition to the acquisition of the data, the USGS is involved in the coordination of geographically referenced or spatial data used in GIS. The backbone of GIS technology is reliable and usable data that can be easily disseminated to and accessed by the many agencies at Federal, State, and local levels, as well as the private sector, who use GIS to solve problems of resource assessment, land use applications, and environmental issues. CD-ROM (compact disk, read-only memory) technology is providing GIS researchers with an excellent medium by which to disseminate the vast files of spatial data that are crucial to GIS. Counterclockwise from bottom: Map produced by using a GIS (see p. 23). Digital elevation data portrayed in a three-dimensional perspective view (see article, p. 96). Digital geologic map of a section of southeastern Puerto Rico (see article, p. 4). Arctic Data Interactive-Climate change data available on CD-ROM (see Information Systems Hypothetical seismic zonation map produced by using a GIS (see article, P. 7). Areal distribution of atrazine concentrations in the lower Kansas River basin (see article, p. 76). Back Cover.-The way maps and other data have been stored or filed as layers of information in a GIS makes it possible to perform complex analyses. The illustration on the back cover of the Yearbook is an example of a computer screen generated with a GIS. The information stored about the location, displayed here graphically, that can be retrieved from the GIS includes the latitude, longitude, projection, and coordinates of an exact location and additional information, such as the road system in the area, the closeness of a location to wells, sources of pollution, and the slope of the land (see p. 23). Message from the Director For or centuries, maps and geographic information have helped people understand and manage their environment. From simple street plans to complex representations of land surface, maps have helped form our understanding of the Earth. The advent of the satellite era and new remote sensing technologies allowed us to view our home from space and to collect global data. Great advances in computer technology permitted scientists to compare massive amounts of information and to develop new insights into the land on which we live. Our view of the Earth began to change. Today we are combining the strengths of traditional printed maps with the force of remote sensing data and the power of modern computing in geographic information systems (GIS) to help us visualize new ways of understanding and managing our planet. The U.S. Geological Survey is using GIS technology for such diverse projects as tracing the distribution of glacial sediments in three dimensions to assist in accurate assessments and balanced use of our Nation's resources. These powerful computing tools also allow scientists to pinpoint geological hazards so that realistic prevention, mitigation, and disaster response measures can be taken. Actions to protect or restore water supplies are aided by the complex analyses that can be handled efficiently by using GIS. By applying GIS technology in such areas as water resources protection, land management planning, and natural disaster prevention, scientists are providing citizens, resource managers, and decisionmakers with vital environmental information faster than ever before. The USGS is not alone in creative uses of GIS. More than 95 Federal agencies are using GIS, and thousands of State and local government agencies and private companies are tracking land use and ownership and making land management decisions with this new technology. The success of GIS technology is based firmly in the availability of high-quality digital data. Developing those data is a considerable challenge, and billions of dollars are being invested each year to meet these expanding data needs. The Secretary of the Interior has been assigned the challenge of coordinating the Federal Government's geographic data activities as head of the recently established Federal Geographic Data Committee. Interior Secretary Manuel Lujan, Jr., has asked the USGS to chair this committee on his behalf. Serving as the broker between data users and producers and attempting to ensure that appropriate, high-quality data are available at the lowest possible price, the USGS is coordinating with other agencies within the Department of the Interior, as well as with the Departments of Agriculture, Commerce, Defense, Energy, Housing and Urban Development, State, and Transportation. We are also working closely with the U.S. Environmental Protection Agency, Federal Emergency Management Agency, Library of Congress, National Aeronautics and Space Administration, the Smithsonian Institution, and other independent agencies. This year, the Survey's mission of "Earth Science in the Public Service" was put to the test before, during, and after the eruption of Mount Pinatubo in the Philippines. Countless lives and billions of dollars in equipment were saved through the hard work, sophisticated instrumentation, and dedication of all involved. The USGS, government of the Philippines, Philippine Institute of Volcanology and Seismology, Department of Defense, and Agency for International Development worked together as a team during the volcanic crisis. Because of the quick deployment of monitoring equipment and the preparation of a volcanic hazards map by Filipino and USGS scientists, there were accurate warnings of impending eruptions. The effective communications among the governments and agencies involved and the confidence in the professionalism of all the scientists and officials ensured that the cooperative effort at Mount Pinatudo was both a scientific and a humanitarian success. USGS water resources monitoring programs, such as tracking the effects on water quality of pesticide use in the Nation's agricultural regions and studying potential interactions between ground water and low-level radioactive waste, provide the information and understanding to support the President's water-quality initiative. In 1991, National Water Quality Assessment program studies that began at 20 sites across the country are the first phase in an eventual 60-site assessment of trends and changes in the quality of the Nation's water resources. Understanding how Earth systems interact is a complex challenge. The use of GIS, the hazards work at Mount Pinatubo, and the National Water Quality Assessment are but three examples of how the USGS is working to advance our understanding of the Earth to help guide environmental and resources development policy in the future. Cooperative agreements and integrated data enhance USGS investigations into the fundamental processes that mold our planet. As we gain insight into these processes, we will be better equipped to assist the agencies of the Department of the Interior, and other government and private groups at all levels, in reaching our shared stewardship goals and ensuring the preservation and enjoyment of our rich natural resources today and for the future. Darlash. Pack Dallas L. Peck iv |