The U.S. Geological Survey (USGS) is the go-to source for geographic and scientific data on the natural environment in the United States. USGS produces datasets and tools that support mapping, research, and decision-making in geology, hydrology, biology, and land use. If you're building maps related to terrain, water, natural hazards, or land cover, USGS is essential.
What Is the USGS?
The USGS is a scientific agency under the U.S. Department of the Interior.
It collects, monitors, and analyzes data on:
- Earth’s surface
- Natural resources
- Natural hazards
- Water systems
- Ecosystems
Most data is freely available and updated regularly.
Core USGS Data Products for GIS
The National Map
A central hub for topographic and base data. It includes:
- Elevation data (DEM)
- Land cover
- Hydrography (streams, lakes)
- Boundaries (state, county)
- Transportation
- Geographic names
- Orthoimagery (aerial photos)
Download from: nationalmap.gov
National Hydrography Dataset (NHD)
Detailed map of U.S. water features:
- Streams
- Rivers
- Lakes
- Flow direction
Often used for watershed analysis and environmental modeling.
3D Elevation Program (3DEP)
Provides high-resolution elevation data:
- Digital Elevation Models (DEMs)
- Lidar-based terrain models
- 1-meter and finer resolutions in many areas
Used for flood modeling, landform mapping, and slope analysis.
EarthExplorer
A searchable platform for satellite and aerial imagery:
- Landsat data
- MODIS
- Sentinel (via partnership)
- Historical aerial imagery
Search and download from: earthexplorer.usgs.gov
National Land Cover Database (NLCD)
Detailed land cover classification across the U.S., including:
- Forest
- Urban
- Agriculture
- Water
- Wetlands
Updated every few years. Used for urban planning, agriculture, and climate studies.
Mineral and Geology Data
USGS provides:
- Geologic maps
- Mineral resources
- Earthquake hazards
- Volcanic activity
- Soil chemistry
Great for natural resource management and hazard analysis.
Tools for Access and Analysis
- TNM Download Client – Directly download elevation, land cover, and hydrography data.
- USGS ScienceBase – Central repository of datasets and metadata.
- National Map Viewer – Interactive web map with customizable layers.
- LandsatLook – Quick view and download of Landsat images.
- TopoView – Explore and download historical topographic maps.
Common GIS Use Cases
Terrain Analysis
Use DEMs and contour lines to study slope, aspect, and elevation.
Watershed Modeling
Use hydrography data to define drainage areas and flow paths.
Land Cover Change
Analyze urban growth or deforestation using NLCD over time.
Natural Hazard Mapping
Overlay fault lines, floods, or fire zones with population layers.
Planning and Infrastructure
Use base maps and elevation data for road planning or environmental impact.
File Formats and Compatibility
USGS data is available in GIS-friendly formats:
- Shapefile (.shp)
- GeoTIFF (for raster data like elevation)
- KML (for use in Google Earth)
- CSV and metadata files
Easily integrated into platforms like QGIS, ArcGIS, or Atlas.
Tips for Using USGS Data in GIS Projects
- Use metadata – Every dataset includes a metadata file. Always read it.
- Clip to area of interest – USGS datasets are often large; focus on your region.
- Coordinate systems – Most data is in UTM or geographic (WGS84). Reproject if needed.
- Layer with other datasets – Combine land cover with census or transport data for deeper insights.
- Check update cycles – Some products update annually, others less often.
Licensing and Use
All USGS data is public domain.
That means you can use, modify, and share it without restriction. Just credit USGS when possible.
