GTOPO30: Global 1-km Digital Elevation Model

GTOPO30 is a global raster digital elevation model (DEM) providing terrain elevation data with a horizontal grid spacing of 30 arc seconds, approximately 1 kilometer. The dataset was completed in late 1996 after a three-year collaborative effort led by the U.S. Geological Survey's EROS center, with contributions from NASA, UNEP, and other international agencies. It was derived from multiple raster and vector topographic sources and is distributed in tiled files for easier access.

Use Cases

• Large-scale hydrological modeling based on global terrain elevation and slope.
• Regional climate and weather simulation using underlying topography data.
• Geographic information system (GIS) analysis for global landform classification.
• Visualization and creation of global relief maps from the raster elevation grid.

Strengths

• Provides complete global coverage of land surface elevation.
• Derived from multiple authoritative international topographic sources, suggesting a consolidated product.
• Developed through a formal, multi-year collaboration led by the U.S. Geological Survey's EROS center.

Limitations

• The dataset's creation date (1996) indicates it is a historical snapshot and may not reflect recent terrain changes.
• Key metadata such as row count, file size, and specific license are unavailable across all sources.
• The 1-kilometer resolution is coarse for applications requiring fine-scale topographic detail.

Provenance

Source

U.S. Geological Survey's Center for Earth Resources Observation and Science (EROS), with contributions from NASA, UNEP/GRID, USAID, INEGI (Mexico), GSI (Japan), Manaaki Whenua Landcare Research (New Zealand), and SCAR.

Collection Method

Derived from several raster and vector sources of topographic information.

Time Range

Snapshot circa 1996.

Geography

Global land surface.