Washington and Landsat: Watching a State Change From Space

Washington is a state of wild wonders and contrasts — from its rugged coast to the volcanic Cascades, with rainforests west of the mountains and deserts east of them. Half the state is forested, and its orchards grow more than half of the apples sold in the United States. Its rivers matter too, above all the Columbia, the largest North American river flowing into the Pacific, whose basin holds dozens of dams, including Grand Coulee, the nation's largest hydroelectric producer.

Washington's landscapes change — some slowly, like urban growth around Puget Sound, some suddenly, like the 1980 eruption of Mount St. Helens, one of the largest volcanic eruptions and the cause of the largest landslide in U.S. history. Change can be hard to see at any moment, but Landsat satellites provide an objective view over decades.

Mount St. Helens' recovery

Before the eruption, old-growth forests of Douglas fir (Pseudotsuga menziesii) and hemlock surrounded the volcano. The eruption and the landslides to the north burned, buried or flattened the trees, leaving more moonscape than landscape. In the 40-plus years since, forests and other plants have come back. USDA Forest Service scientists used Landsat to track that recovery and build a model that predicts percent tree cover.

Landsat images of Mount St. Helens from July 19, 1984 (left), and July 25, 2021 (right), showing plants returning. U.S. Geological Survey.

Monitoring landscapes and habitats

Small changes matter as much as big ones, and Landsat's long archive reveals trends that help plan the future.

• At Olympic National Park — 922,000 acres of coast, rainforest and mountains — the National Park Service used 26 years of Landsat data and LandTrendr algorithms to map eight kinds of change, including forest clearing and wildfire, in and around the park.
• NOAA and Oregon State University researchers used LandTrendr to map 23 years of land cover next to habitat of threatened Chinook salmon in Puget Sound, measuring how much had been developed.

Landscape changes in and around Olympic National Park, 1985–2010, by year of onset, mapped from Landsat. National Park Service.

After wildfires

Washington, like other western states, faces increasingly severe wildfires. One tool built on Landsat is RECOVER (Rehabilitation Capacity Convergence for Ecosystem Recovery), developed by NASA, Idaho State University and the Bureau of Land Management to deliver fire-effects data quickly to land managers. After fires near Spokane in 2016, a National Weather Service hydrologist and a science team used RECOVER to map burn severity and assess the risk of flash floods and debris flows.

A fire in Olympic National Forest. U.S. Department of Agriculture Forest Service.

Landsat for the nation

• The USGS National Land Imaging Program supplies satellite and other geospatial data to government, business, universities and the public, with worldwide Landsat access through the USGS EROS Center.
• Landsat is the most widely used land remote-sensing source among federal civilian agencies, and local, state and tribal agencies rely on it too — for decisions that protect life and property, safeguard the environment, advance science and education, support climate resilience and grow the economy.
• Businesses use it to improve logistics, resource allocation and investment; commercial imaging firms build products on it. A 2017 USGS study put Landsat's annual economic benefit to the U.S. at $2.06 billion, far more than its cost.
• Landsat 8 and 9 together image Earth's land every 8 days. NASA and the USGS are planning Landsat Next to extend the 50-year record — the world's longest of Earth's land surface.
• With consistent data and a no-cost policy, plus cloud computing, Landsat is used every day, like GPS and weather data, to understand a changing planet.

Sources

Based on U.S. Geological Survey Fact Sheet 2022–3021, "Washington and Landsat"; a work of the United States government in the public domain.