Eyes on Earth

The invasive species hemlock woolly adelgid is a threat to eastern hemlocks, filling some southeastern U.S. forests with what are called “gray ghosts” of the trees. Until recently, the insect had stayed in the southern part New York, but late last summer, an infestation was discovered in the Adirondacks.

The fire science community is always on the lookout for the freshest satellite-derived fire disturbance maps. Aiming to meet those needs, the multi-agency partnership known as LANDFIRE has just released an update that adds three new years of disturbances across the U.S. to its 20-plus layers of GIS data.

About 15 million people rely on the Delaware River Basin for drinking water, including residents of Philadelphia, PA, Camden, NJ, and Wilmington, DE. What might happen to the water supply if climate change and population growth continue unabated? How might that impact land cover and land use patterns?

Teams at the USGS EROS Center have completed fire atlases for nine National Parks across the U.S. Each atlas defines the size and severity of each fire in each park since 1984, including fires too small to be mapped by other programs. Yellowstone National Park has had nearly 100 fires, for example, ranging from a few acres to thousands of acres.

It’s possible to map vegetation type with Landsat, but getting the maps right requires more than satellites alone. The teams behind LANDFIRE use an extensive network of ground control points to check their work, thereby bolstering the reliability and utility of their multi-layer GIS product suite.

Ladies of Landsat aims to help women and other underrepresented groups feel welcomed and supported in the field of remote sensing. The Twitter group has grown to 5,700 members and counting since Dr. Kate Fickas started it in 2018 during a Landsat Science Team meeting at EROS.

Deforestation is a significant concern for many parts of the globe, particularly in places like the rainforests of the Amazon or the Congo. Scientists, governments, and non-governmental organizations turn to satellite data to track deforestation, as well as to set targets for improvement.

Landsat satellites have monitoring the Earth’s surface for nearly 50 years, providing critical information for countless areas of study and real-world applications. But with observations only collected every 8-16 days, there are limits to what can be tracked.

Dr. Alan Belward has spent a lot of time thinking about the planet’s surface water. The former Landsat Science Team member uses satellite data to track changes to lakes, rivers, and streams, and recently published a book that uses Landsat data to tell some of those stories.

The St. Mary and Milk Rivers cross the U.S. and Canadian border and supply water to both countries. Managing that resource in the interest of both nations is a matter of international collaboration and cooperation, and Landsat data is helping offer objective information on water use.

The extensive rangelands across the Western United States are threatened by invasive grasses, climate change, and altered fire regimes that can disturb the landscape. The largely semi-arid lands are also important for the survival of species that need undisturbed sagebrush ecosystems to thrive.

Albedo—the amount of incoming solar radiation reflected into space from the Earth’s surface—is a key measurement for surface temperatures and plant productivity. It also factors into weather forecasting and climate modeling. Landsat Science Team member Dr.

Landsat data is more useful today than at any other point in its nearly 50-year history. The USGS Collections strategy is a major reason why. Landsat Collections align and correct satellite acquisitions from 1972 through the present to make the data easier to work with through time.

Brazil is a fascinating study in water use. Brazil uses roughly 72 percent of its water for irrigated agriculture, and its herds of cattle, pigs and poultry are among the largest in the world.

In the past, remote sensing scientists looked for change on the Earth’s surface primarily by comparing one Landsat image to another.

The Green Revolution leaned on fertilizers, drought-resistant seeds and other modern innovations to boost agricultural production across much of the planet in the second half of the 20th Century. But many of those innovations never reached West Africa, partially because the lack of social safety nets and crop insurance made such investments too risky.

When a disaster like a hurricane, flood or major wildfire hits a remote part of the world, the International Charter Space and Natural Disasters springs into action.

Evapotranspiration is the process by which water transpires from the leaves and stems of plants and evaporates from the Earth’s surface. ET is an important metric for managing water use, but data availability has long been an issue.

Today, the world is awash in remotely sensed data. Satellites launched by countries and commercial companies circle the planet collecting data every day. Accessing data from multiple agencies and plaforms and turning it into useful analytics can be a daunting and complex endeavor, however.

Mapping land cover across the United States using Landsat satellite data is a difficult, time-intensive job, but there are jobs far larger. Matt Hansen, a Maryland-based professor and member of the Landsat Science Team focuses his efforts on mapping land cover and change on a global scale.

Calibration teams at the USGS EROS Center use a variety of methods to make sure the data collected by Landsat satellites are an accurate representation of the Earth’s surface.