How Landsat Serves South Dakota

This USGS fact sheet describes Landsat and its plans as they stood when it was written.

Few states depend on their land as much as South Dakota. Agriculture is its main industry: the fertile soil of eastern South Dakota consistently produces some of the country's largest corn and soybean yields, and the state is a top producer of spring wheat, flaxseed, hay, oats, rye and sunflower seeds. Tens of thousands of visitors come each year to hunt the state bird, the ring-necked pheasant, and the waterfowl of the prairie pothole region in the northeast, or to see the Black Hills, Mount Rushmore and Badlands National Park in the west.

Energy and mining matter too. Much of the corn not eaten or fed to livestock goes to the state's ethanol plants, and hydropower from the Missouri River supplies most of the energy used by its 800,000 residents. All but one of its gold mines have closed, but mining continues for mica, construction sand and gravel, crushed stone and more.

Landsat data, archived at the USGS Earth Resources Observation and Science (EROS) Center just outside Sioux Falls, have long helped monitor, map and manage the state's land.

Cropland and water use

Landsat imagery is a key input to the U.S. Department of Agriculture's Cropland Data Layer, an interactive mapping tool that has tracked crop types across the lower 48 states every year since 2009. Combining survey data and Landsat imagery, it helps monitor the food supply and lets state agricultural leaders follow trends over time and place.

The USDA's Cropland Data Layer uses Landsat and other data to map the crops grown in the United States. Image from the USGS fact sheet.

Landsat also feeds models of evapotranspiration (ET), the water given off by plant leaves plus the water evaporating from the land surface, which also serves as a measure of how efficiently water is used. ET models can gauge South Dakota's water use, inform soil health studies and signal drought stress. Landsat can also measure how bad weather hurts crops, as in 2019, when so much rain soaked the state's soil that South Dakota led the nation in prevented-planting crop insurance payments.

Prairie pothole wetlands

South Dakota's prairie pothole region is one of the most important stops for migrating waterfowl in North America, and a draw for anglers and hunters. Many seasonal wetlands have been drained for crops, while surface water has grown in other places. Landsat's 50-year record lets researchers study how the lakes have changed over that span, deepening knowledge of this vital habitat and allowing broader studies of the long-term effects of conservation programs and farming. Newer ready-made Landsat products such as Dynamic Surface Water Extent make it simpler to study water resources over large areas and long periods.

Black Hills forests

Visitors to the Black Hills watch bison and bighorn sheep on slow, scenic drives through Custer State Park and Black Hills National Forest, but those forests face constant threats from fire and invasive species. The Legion Lake Fire burned 54,000 acres in 2017, and the mountain pine beetle has affected about 430,000 acres of forest in recent decades.

A Landsat 8 false-color image of the Legion Lake Fire burn scar in western South Dakota. The bright red scar shows up in Landsat's shortwave infrared and near-infrared bands. Image from the USGS fact sheet.

Because Landsat records light the eye cannot see, it can track wide-scale damage and follow recovery. Landsat-based maps also inform tools that help local leaders manage the wildland–urban interface in places like the Black Hills. Data from the Landsat-based LANDFIRE product suite were a baseline input for the USDA Forest Service's Wildfire Risk to Communities portal, the first nationwide tool built to assess fire risk to communities, homes and businesses.

Landsat nationally

• Access: the USGS National Land Imaging Program supplies satellite imagery and other remote sensing and geospatial data to government, business, universities and the public, and funds the EROS Center, which provides worldwide access to Landsat data.
• Use: Landsat is the most widely used source of land remote sensing data in federal civilian agencies, helping local, state, tribal and federal agencies monitor and forecast changes on the land.
• Value: a 2017 USGS study put Landsat's total annual economic benefit to the United States at $2.06 billion, far more than it costs to build and run.
• Coverage: Landsat 8 and Landsat 9 together image the Earth's land every 8 days, extending a 50-year series, the world's longest record of the land surface, with data available at no cost.
• What is next: NASA and the USGS were reviewing the findings of a joint Architecture Study Team to shape Landsat Next, the mission to follow Landsat 9.

Sources

• U.S. Geological Survey, "South Dakota and Landsat," Fact Sheet 2021–3035. https://pubs.usgs.gov/publication/fs20213035/full
• The fact sheet cites Savoca and others (2013) on evapotranspiration, the Farm Service Agency (2020) on prevented planting, Rover and others (2011) on lake dynamics, the Forest Service (2020) on the Black Hills, Scott and others (2020) on wildfire risk, and Straub and others (2019) on Landsat's economic value.