How Landsat Maps Georgia: Forest Loss, New Development and Atlanta's Hot Spots

Georgia is called the Peach State, but it could as well be called the State of Abundance. It has more than 10 million residents, 6 million of them in greater Atlanta, and it is one of the country's top timber producers. With that much growth pressing on that much forest, the state watches its land change from orbit — with Landsat.

An atlas for every county

GeorgiaView, a member of the national AmericaView education and outreach consortium, supports the use of remote sensing across the state. Since 2019 it has published three volumes of the Georgia Land Cover Image Atlas, based largely on Landsat data. Each has maps for every congressional district, every regional commission and all 159 counties:

The point is easy access: local and regional officials get ecosystem information without needing to process satellite data themselves.

Keeping the forests whole

Macon, beyond the forests around Brown's Mount in Bond Swamp National Wildlife Refuge. Forests cover about two-thirds of Georgia. Credit: Bill O'Brian, U.S. Fish and Wildlife Service.

The timber industry and forest-based tourism have an economic impact of $28 billion in Georgia. Forests also improve water and air quality, and in cities they help manage stormwater and cool urban hotspots. The Georgia Forestry Commission uses Landsat to assess and prioritize forest as urbanization advances. By comparing land cover maps from 1974 to 2008, it traced how forests had been fragmented and identified the sizable unbroken forest areas that remain — the ones to prioritize for conservation.

Finding Atlanta's hot spots

Scientists have studied Atlanta's urban heat island effect for decades. Urban heat islands are parts of a city with more pavement and other impervious surfaces and fewer natural features, where temperatures by day and night exceed those of the surrounding area. They put vulnerable residents at higher risk of heat-related illness or death, especially during heat waves.

Landsat's thermal sensors measure the temperature of the land's surface, which helps pinpoint heat islands — and can show where lost forest may have pushed temperatures up. In 2017, Central Atlanta Progress, a nonprofit community development organization, and the Atlanta Downtown Improvement District drew up the Downtown Atlanta Master Plan to guide improvements. A 2019 technical analysis from the Georgia Institute of Technology then used Landsat to map land surface temperatures and locate the most intense downtown heat.

Landsat surface temperature over Atlanta: green is cooler, red warmer. The Atlanta and Inman railyards stand out as warm. Credit: U.S. Geological Survey.

Why Landsat

• It is the most widely used source of land remote sensing data in federal civilian agencies, and local, state and Tribal agencies use it too.
• Landsat 8 and Landsat 9 together revisit Earth's land every 8 days.
• Its record runs more than 50 years — the world's longest time series of Earth's land surface.
• The data cost nothing to use, through the USGS Earth Resources Observation and Science (EROS) Center, funded by the National Land Imaging Program.
• A 2024 study put its total annual economic benefit at $25.6 billion, far more than it costs to build and run.
• NASA and the USGS are working toward launching Landsat 10 in 2031.

Sources

Based on the USGS fact sheet "Georgia and Landsat," a work of the United States government in the public domain. It cites GeorgiaView (2021), the Georgia Forestry Commission's statewide assessment of forest resources (2015), the Downtown Atlanta Master Plan (2017), Garcia and others (2019, Georgia Institute of Technology) and Loomis and others (2024) on Landsat's economic value.