Virginia From Orbit: What Landsat Does for the Chesapeake, Its Forests and Its Cities

The lands that became Virginia were among the first in North America to be transformed by European settlement, beginning at Jamestown in 1607 — the first permanent English settlement in what became the United States, whose site now lies within Williamsburg. Today the state is a hub of federal government, home to the headquarters of the U.S. Geological Survey, the Fish and Wildlife Service, the Marshals Service and more in northern Virginia; its forests, Blue Ridge peaks and Chesapeake Bay shores keep drawing people in. Landsat, the USGS satellite series with more than 50 years of images, is one of the main ways its land and water are watched.

The Chesapeake Bay

The bay is a national treasure and central to Virginia's economy. Nearly 350 species of fish live there, along with prized oysters and crabs; the largest fish, the Atlantic sturgeon, spawns in the James and York Rivers. Commercial and recreational fishing bring Virginia $1.3 billion a year and make it the Atlantic coast's leading seafood producer.

Keeping the bay healthy takes streamgages, water sampling — and satellites, which can follow swirling sediment and harmful algal blooms, fed by nitrogen and phosphorus running off the land. Landsat's 30-meter images, combined with coarser daily imagery, can track trends in chlorophyll that signal a bloom.

The Chesapeake Bay in a mosaic of Landsat images. USGS

The forests

The George Washington and Jefferson National Forests cover the Appalachians in Virginia, and the forest products industry is worth $21 billion a year. Landsat's long record helps foresters map and protect them:

• The U.S. Forest Service and the USGS built a 30-meter tree-canopy map from Landsat, showing how much of the land is forested.
• Virginia Tech researchers used cloud computing to scan the whole Landsat archive and tell pine thinning on private land apart from logging and untouched stands — changes that matter for forest health, regrowth and carbon models (Thomas and others, 2021).
• A study of invasive evergreen shrubs in the Shenandoah area found an unexpected decline in winter greenness since 1985, which is reshaping questions about how invaders spread (Donahoe and Kennedy, 2020).

The cities

Growth has slowed since 2010 but continues around cities such as Richmond. Pavement, roofs and parking lots change where rainwater goes and trap heat by day and night. Landsat measures how much of the land they cover through the National Land Cover Database, which helps planners decide where and how to build (Parece and Campbell, 2013), and its thermal sensors map urban hot spots so cities can target cooling efforts.

Land-cover data derived from Landsat, around Richmond. USGS

Landsat for everyone

The USGS National Land Imaging Program delivers Landsat and other remote-sensing data worldwide, free, through the Earth Resources Observation and Science (EROS) Center. Landsat is the most widely used land-imaging source among federal civilian agencies, and local, state and tribal governments, businesses and commercial imaging firms build on it. A 2024 study put its economic benefit at $25.6 billion a year, far more than it costs (Loomis and others, 2024).

Landsat 8 and 9 together image the whole land surface every 8 days. NASA and the USGS are working toward Landsat 10, planned for 2031, to extend the world's longest continuous record of the Earth's land.

Sources

Written from Virginia and Landsat, U.S. Geological Survey Fact Sheet; a work of the United States government in the public domain. It cites the Chesapeake Bay Program (2021), NASA (2015), the U.S. Forest Service (2021), Thomas and others (2021), Donahoe and Kennedy (2020), Parece and Campbell (2013) and Loomis and others (2024).