The National Map

The National Map
Name	The National Map
Country	United States
Agency	United States Geological Survey
Established	1997
Type	National geospatial dataset

The National Map The National Map is a collaborative geospatial initiative produced by the United States Geological Survey to provide consistent topographic, hydrographic, transportation, and elevation data for the United States. It serves as a foundational spatial data infrastructure supporting agencies such as the Federal Emergency Management Agency, the National Oceanic and Atmospheric Administration, and the Bureau of Land Management while interfacing with national efforts like the National Spatial Data Infrastructure and international frameworks including the Global Spatial Data Infrastructure.

Overview

The National Map aggregates authoritative datasets including digital elevation models, hydrography, orthoimagery, transportation, structures, and land cover to support mapping, analysis, and decision making across federal programs such as the National Weather Service, the Environmental Protection Agency, and the Department of Transportation. It complements products and portals from the Library of Congress, the U.S. Census Bureau TIGER datasets, and the National Aeronautics and Space Administration remote sensing missions while aligning with standards promulgated by the Federal Geographic Data Committee. Stakeholders range from the National Park Service and state departments of transportation to private sector firms like Esri and academic centers including the Center for Spatial Research.

History and Development

Origins trace to modernization efforts following initiatives by the U.S. Geological Survey and policy directives such as the Paperwork Reduction Act and the establishment of the National Spatial Data Infrastructure in the 1990s. Major milestones include integration of the National Hydrography Dataset and the transition from paper quadrangles to digital products influenced by programs like the Landsat series and the Shuttle Radar Topography Mission. Collaborations with agencies such as the U.S. Forest Service and the Natural Resources Conservation Service expanded data content, while partnerships with state geospatial offices and projects like the National Elevation Dataset and the National Land Cover Database drove interoperability. Funding and policy decisions involving the Office of Management and Budget and the Congress shaped program scope and modernization priorities.

Data and Services

Core datasets encompass hydrography compiled in coordination with the National Hydrography Dataset, elevation data derived from sources including the Shuttle Radar Topography Mission and airborne lidar programs used by the Federal Emergency Management Agency for floodplain mapping, orthorectified imagery analogous to products from the National Agriculture Imagery Program, and vector layers for transportation and structures consistent with U.S. Census Bureau and Federal Aviation Administration datasets. Services include web map services and web feature services compatible with standards from the Open Geospatial Consortium and metadata compliant with the International Organization for Standardization and FGDC guidelines. The program provides downloadable products usable by GIS platforms from vendors such as Esri and open-source projects like QGIS and PostGIS.

Applications and Use Cases

The National Map supports hazard response and recovery for events like Hurricane Katrina and wildfire incidents coordinated with the Federal Emergency Management Agency and the U.S. Forest Service, informs infrastructure planning for Department of Transportation projects and Federal Highway Administration programs, and underpins conservation and land-use planning activities of the National Park Service and the U.S. Fish and Wildlife Service. Researchers at institutions such as Massachusetts Institute of Technology and Stanford University use its datasets for hydrologic modeling, while companies like Google and Apple Inc. leverage base data for consumer mapping products. Educational uses span curricula at universities including the University of California, Berkeley and University of Minnesota where instructors incorporate elevation and hydrography layers for field studies and classroom labs.

Technical Architecture and Standards

Architecture employs a service-oriented model exposing data via Web Map Service and Web Feature Service endpoints compatible with Open Geospatial Consortium specifications, using formats such as GeoTIFF for raster elevation and imagery and Esri-compatible shapefiles or GeoPackage for vector layers. Metadata adheres to standards from the Federal Geographic Data Committee and ISO 19115 while persistent identifiers and versioning practices follow guidance from the National Information Exchange Model and Federal data policy instruments administered by the Office of Management and Budget. Interoperability is facilitated through use of coordinate reference systems like North American Datum of 1983 and Universal Transverse Mercator zones, and datum transformations endorsed by the National Geodetic Survey.

Access, Licensing, and Updates

Access mechanisms include online viewers, bulk downloads, and APIs enabling integration with platforms employed by the U.S. Geological Survey, state geospatial portals such as the California Geoportal, and international clearinghouses coordinated with organizations like the United Nations Committee of Experts on Global Geospatial Information Management. Licensing follows public domain principles consistent with federal data practices overseen by the Office of Management and Budget and supports redistribution by partners including commercial firms, academic institutions, and non-governmental organizations such as the Nature Conservancy. Update cycles vary by dataset and are synchronized with partner programs including the National Elevation Program and state mapping initiatives, with change detection informed by satellite missions like Landsat and Sentinel-2.

Category:United States Geological Survey Category:Geographic information systems Category:Topography