How Landsat Serves Maryland

Maryland is called "America in Miniature" because it has nearly every kind of U.S. landscape except desert. Water dominates the state, whose borders follow much of Chesapeake Bay, the country's largest estuary, where fresh water from tributaries meets salt water from the ocean and teems with life. The bay faces erosion, pollution, rising seas and natural disasters, and because it is central to Maryland's history, economy, nature and way of life, protecting it is a state priority. Maryland also has a special tie to Landsat: the U.S. Geological Survey (USGS) runs the satellites' flight operations from NASA's Goddard Space Flight Center in Greenbelt.

Chesapeake Bay, America's largest estuary, assembled from five Landsat 8 scenes taken in October and November 2014. U.S. Geological Survey.

Cutting pollution in the bay

Maryland and the other states that drain into Chesapeake Bay set total maximum daily loads (TMDLs), estimates of how much of certain pollutants, such as excess nutrients, sediment and contaminants, a body of water can take before its quality suffers. Landsat land-cover data help set those limits and pinpoint areas to target for nonpoint source pollution, partly by showing what kind of surface runoff crosses, whether pavement, cropland or forest.

Helping farmers reduce runoff

The Maryland Department of Agriculture pays farmers to plant winter cover crops, which help prevent erosion and runoff. Images from Landsat 5 and Landsat 8 helped build a tool that lets the department check how well the cover crops are working without visiting each farm, and find ways to use them better.

Winter cover crops on farmland along Tuckahoe Creek and the Choptank River on the Delmarva Peninsula, photographed by Landsat 8's Operational Land Imager on January 5, 2015. U.S. Geological Survey.

Assessing coastal wetlands

The USGS uses Landsat to assess coastal wetlands, which change through slow processes such as sea-level rise and sudden ones such as storms. Assateague Island, a barrier island off Maryland famous for its wild horses, saw major erosion, saltwater overwash and new deposits from Hurricane Sandy. Understanding how ocean coastlines, estuary shores and barrier islands, including their interior wetlands, connect helps coastal managers anticipate and plan for future events.

Wild horses of Assateague Island National Seashore in a salt marsh. National Park Service.

Mapping high-tide flooding

Rising seas have made flooding from unusually high tides more frequent along Maryland's shore. Landsat 7 and 8 have helped map it. In Annapolis, one flood-prone place, water can fill streets and parking lots and even reach the U.S. Naval Academy. The phase of the moon, wind direction and sinking land all add to these high tides.

The U.S. Naval Academy in Annapolis has taken steps to limit flood damage, but Ramsay Road routinely floods at high tide. U.S. Naval Academy.

Landsat nationally

• Access: the USGS National Land Imaging Program provides satellite and other geospatial data to government, business, universities and the public, and funds the USGS Earth Resources Observation and Science (EROS) Center, which gives worldwide access to Landsat data.
• Use: Landsat is the most widely used land remote sensing data source in federal civilian agencies.
• Value: a 2024 study put Landsat's total annual economic benefit at $25.6 billion, far more than it costs to build and run.
• Coverage: Landsat 8 and 9 image the Earth's land every 8 days, extending a record of more than 50 years, the world's longest of the land surface, with free data.
• What is next: NASA and the USGS are working toward launching Landsat 10, with significant improvements, in 2031.

Sources

• U.S. Geological Survey, "Maryland and Landsat," Fact Sheet 2021–3022. https://pubs.usgs.gov/publication/fs20213022/full
• The fact sheet cites USGS (2017) on pollution loads, Voiland (2017) on cover crops, Douglas and others (2018) on coastal wetlands, Marder (2020) on high-tide flooding, and Loomis and others (2024) on Landsat's economic value.