Higher-Resolution Elevation Data Transform Climate and Ecosystem Research in Africa

On September 23, National Aeronautics and Space Administration (NASA), National Geospatial-Intelligence Agency (NGA), and the U.S. Geological Survey (USGS) announced the public release of higher-resolution elevation datasets for Africa. The data, derived from the Shuttle Radar Topography Mission (SRTM), increase spatial detail from 90-meter to 30-meter resolution and are freely accessible via the USGS Earth Explorer platform.

This release aligns with a U.S. commitment made at the United Nations to strengthen global climate change response. By improving baseline elevation information across most of the African continent, the enhanced datasets provide critical support for climate modeling, disaster mitigation and environmental management.

Why Elevation Matters

Elevation—often referred to as the “third dimension” of mapping—fundamentally shapes natural systems. Topography determines surface water flow, influences local temperature gradients and defines coastlines, floodplains, marshes and riverbanks. It affects salinity distribution, habitat range and ecological boundaries.

When combined with other geospatial variables, elevation data support:

• Hydrological modeling and watershed analysis
• Coastal vulnerability assessments
• Species habitat mapping
• Public health risk forecasting
• Infrastructure planning and resilience studies

In Africa, where many communities face climate-related hazards, precise topographic information enhances preparedness and decision-making.

From 90 Meters to 30 Meters

Until this release, publicly available SRTM elevation data for Africa were limited to 90-meter resolution. The new 30-meter datasets significantly improve terrain detail, enabling more accurate modeling of low-relief coastal areas, river deltas and complex highland systems.

Additional releases for Latin America, the Caribbean and other global regions are scheduled within a year, expanding global access to higher-resolution digital elevation models.

Suzette Kimball, then Acting Director of USGS, emphasized the broader value of open data, noting that reliable elevation information supports scientists, educators and policymakers worldwide.

To facilitate adoption, USGS, NASA and NOAA—supported by the Secure World Foundation—plan to conduct online training and regional workshops to help users integrate these datasets into research and operational workflows.

Case Study 1: The Niger River Delta, Nigeria

The Niger River Delta in southern Nigeria is a dynamic coastal ecosystem composed of estuaries, mangroves, tidal flats and lowland rainforests. In such environments, subtle elevation differences can determine whether land remains habitable or becomes inundated.

Climate-related threats in the delta include:

• Flooding and storm surge
• Sea-level rise
• Coastal erosion
• Saltwater intrusion

These hazards are particularly concerning near Port Harcourt, a major urban center with extensive oil infrastructure and a population approaching two million.

Enhanced 30-meter SRTM data improve the representation of small elevation gradients, refining assessments of coastal vulnerability and ecosystem resilience. Research has shown that mangrove forests—highly sensitive to slight topographic variation—serve as natural buffers against storms and tsunamis. More detailed elevation data enhance the monitoring of mangrove health and distribution.

Case Study 2: Senegal-Guinea Highlands

In the transboundary highlands between Senegal and Guinea, biodiversity and land-use change intersect with climate variability. Declining rainfall and expanding agricultural activity are placing pressure on habitats, including gallery forests that provide microclimates critical for wildlife.

Chimpanzee populations in this region exhibit unique adaptations to semi-arid conditions. Protecting their habitat requires accurate terrain and land-cover mapping.

At the request of U.S. Agency for International Development (USAID) and Senegal’s Ministry of Environment, the USGS EROS Center combined Landsat imagery with 30-meter SRTM elevation data to produce a detailed land-use and land-cover map supporting the establishment of the Dindefelo Nature Reserve.

The improved elevation model enhanced three-dimensional visualization and habitat delineation, strengthening proposals to extend protected areas into Guinea. Collaboration with the Jane Goodall Institute underscores the role of geospatial data in conservation planning.

Advancing Disaster Response and Climate Adaptation

Beyond ecosystem mapping, the international Committee on Earth Observation Satellites (CEOS) is coordinating workshops to promote the use of SRTM 30-meter data in flood modeling and disaster response. The first regional workshop is scheduled in South Africa, hosted by the South African National Space Agency (SANSA).

As climate variability intensifies across many regions, improved digital elevation models enhance predictive capacity and inform sustainable land management. By making higher-resolution topographic data freely available, NASA, NGA and USGS are expanding global access to foundational geospatial resources.

Accurate elevation data do more than refine maps—they strengthen climate resilience, protect biodiversity and support evidence-based decision-making across the African continent and beyond.