How Landsat Serves California

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

California is remarkably varied, with 1,100 miles of Pacific shoreline and 33 million acres of trees, including the redwood forests along U.S. Route 101. Nicknamed "The Golden State," it could also be called "The Extreme State." Mount Whitney in the Sierra Nevada, at 14,494 feet the highest peak in the conterminous United States, is about a 2.5-hour drive from Badwater Basin in Death Valley, at 282 feet below sea level the country's lowest point. Hundreds of inches of snow fall on Mount Whitney each year, while Death Valley, often called the hottest place on Earth, averages less than 2 inches of rain.

California is also the most populous state, with 39 million people, 26 million of them near the coast, and the most agriculturally productive, raising fruits, vegetables, nuts, grains, grasses and flowers along with dairy and livestock. Climate change affects many of those people, crops and places, and Landsat helps agencies and residents monitor their land and plan for a resilient future.

Watching the water

With a growing population, rising demand from agriculture and higher temperatures from climate change, fresh water is precious and tightly regulated in California, and agriculture uses nearly 80 percent of the state's supply. Periodic droughts sharpen the competition. Landsat has been central to tools that measure irrigation water use through evapotranspiration (ET), the movement of water into the air by evaporation and plant transpiration. One example is an ET toolkit developed by NASA, the U.S. Department of Agriculture (USDA), Utah State University and the E&J Gallo Winery in the Central Valley, which helps the winery time its grape irrigation and save water and money.

USDA Agricultural Research Service scientists built computer models that use satellite data to map grapevine water use and stress, in collaboration with E&J Gallo Winery. Photo by Jessica Griffiths, USDA ARS.

Understanding wildfires

Wildfires in the western United States have been growing. The August Complex fire of 2020 burned more than 1 million acres in Glenn, Lake, Mendocino, Tehama, Trinity and Shasta counties, by far the largest California fire in modern records. Beyond pictures of fires, Landsat data let the USDA Forest Service and the USGS Earth Resources Observation and Science (EROS) Center map burn severity, how much a fire changed the land. That feeds programs such as LANDFIRE, a multiagency partnership that maps vegetation types with Landsat and builds GIS layers used by state and federal fire agencies, land managers and scientists, and Burned Area Emergency Response, which uses burn severity to find and address post-fire threats such as landslides and flooding.

The August Complex fire, which started August 17, 2020, took nearly three months to contain and burned more than 1 million acres. This Landsat image from September 1, 2020, uses shortwave and near-infrared data to show the northern part of the fire: the hottest areas appear yellow and earlier burns dark brown. NASA.

Classifying vegetation for more than 40 years

Since 1978 the USDA Forest Service has used Landsat in its Classification and Assessment with Landsat of Visible Ecological Groupings (CALVEG) to classify vegetation and support resource planning. It identifies more than 200 types of vegetation communities in nine regions of the state.

How much of California's ecological mapping zones have been mapped for vegetation. All national forest lands in the state are complete; the map shows where and when mapping of all ownerships was finished. USDA Forest Service.

Landsat nationally

• Access: the USGS National Land Imaging Program supplies satellite and other 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 land remote sensing data source in federal civilian agencies.
• 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 image the Earth's land every 8 days, extending a 50-year record, the world's longest of the land surface, with free data.
• What is next: NASA and the USGS were reviewing findings from a joint Architecture Study Team to shape Landsat Next, the mission to follow Landsat 9.

Sources

• U.S. Geological Survey, "California and Landsat," Fact Sheet 2021–3034. https://pubs.usgs.gov/publication/fs20213034/full
• The fact sheet cites NASA (2020) on the ET toolkit, Monitoring Trends in Burn Severity (2021), USDA Forest Service (2021) on CALVEG, and Straub and others (2019) on Landsat's economic value.