For more Information

All GTOPO30 data are available free to the user and can be obtained from the Internet at
http://edcwww.cr.usgs.gov/landdaac/
gtopo30/gtopo30.html

USGS, Partners Map National Land Cover, Global Elevations

Two new information products developed by the USGS and its partners -- the National Land Cover Dataset and the GTOPO30 digital elevation model -- will make new levels of detailed spatial information available to the public.

At a resolution of 98 feet, the National Land Cover Dataset provides the most detailed data ever collected for a national land cover program. Employing satellite imagery and a variety of supporting data such as topography, census, agricultural statistics, and wetland maps, scientists determine and label the land cover type for each 98-foot pixel in Landsat Thematic Mapper images. The information has many uses, including managing land and watersheds, modeling transportation, and assessing fire risks.

In 1997, scientists at the USGS Earth Resources Observation Systems (EROS) Data Center in Sioux Falls, South Dakota, completed a detailed land cover data set for the Middle Atlantic States as part of a 4-year effort to map the conterminous United States. The National Land Cover Dataset, a cooperative project of the Multi-Resolution Landscape Consortium (MRLC), is funded by the U.S. Environmental Protection Agency and USGS.

A new digital elevation model, GTOPO30, provides the first global coverage of moderate-resolution elevation data. The

dataset was developed over 3 years through a collaborative effort led by USGS, and completed in 1996 at the EROS Data Center. This collaboration included the National Aeronautics and Space Administration (NASA), the United Nations Environment Programme Global Resource Information Database (UNEP/GRID), the U.S. Agency for International Development (USAID), the Instituto Nacional de Estadística Geografía e Informática (INEGI) of Mexico, the Geographical Survey Institute (GSI) of Japan, Manaaki Whenua Landcare Research of New Zealand, and the Scientific Committee on Antarctic Research (SCAR). GTOPO30 was developed to meet data users' needs for regional- and continental-scale topographic data. A truly global data set, GTOPO30 covers from 90°S to 90°N and 180°W to 180°E.

A continental-scale digital elevation model such as GTOPO30 is required for climate and global change studies spanning several disciplines: atmospheric science, hydrology, biogeochemistry, wildlife biology, forestry, range science, and others. These data are suitable for many regional and continental uses, such as climate modeling, continental-scale land cover mapping, and geometric and atmospheric correction of certain satellite image data. GTOPO30 provides a new level of detail in global topographic data.

A new digital elevation model, GTOPO30 provides the first global coverage of moderate-resolution elevation data.