How Landsat Helps Connecticut

Connecticut is the third-smallest state by land area and the fourth most densely populated. Its compact cities are international hubs for finance and insurance and home to well-known universities. The U.S. Geological Survey's Landsat satellites, with decades of repeated, landscape-scale observations, help the state study and manage its land and water.

Forests

About 60% of Connecticut is forested, and one of the chief recent threats to those forests has been the spongy moth (formerly called the gypsy moth). Landsat's long record gives valuable insight into moth-caused tree death and ways to reduce it. A 2018 study used it to map the extent of the damage, a 2021 study built a defoliation-prediction model for New England on Landsat data, and the University of Connecticut uses Landsat-based vegetation health information to map possible damage from the moth, drought and other stresses.

The Farmington River near Riverton, Connecticut, in fall. Photo by Paul Solis, USGS.

Cities

New England is generally more densely settled than the rest of the country, and Connecticut especially so. Dense development means more impervious surfaces — parking lots, roads and buildings — which affects runoff, heat and ultimately human health. Pavement and buildings trap heat, keeping cities warmer than surrounding countryside through the day and into the evening, a pattern called the urban heat island, which Landsat's thermal sensors can measure. In 2020, researchers at Yale's School of Forestry and Environmental Management used Landsat to study the loss of urban tree cover and heat in green infrastructure, and the University of Connecticut's Connecticut's Changing Landscapes project used it to map 30 years of land cover and change across the state.

Coasts

Development has affected Connecticut's coastline, the broad estuary of Long Island Sound, and the state's many waters. In 2018 the Interstate Environmental Commission, a water and air pollution agency for New York, New Jersey and Connecticut, reported on hypoxia — low oxygen, a sign of poor water quality — in western Long Island Sound, drawing on Landsat-based information on impervious surfaces, a major driver of fast runoff and hypoxia. Landsat's repeated images also help monitor coastal and inland flooding and storm damage across New England.

Street flooding at high tide during a storm on January 17, 2022, at Crescent Beach in Niantic, Connecticut. Photo by Timothy C. Sargent, USGS.

Landsat nationwide

Through the USGS National Land Imaging Program and its Earth Resources Observation and Science (EROS) Center, Landsat data are available worldwide at no cost. Landsat is the most widely used land remote sensing source in federal civilian agencies, and local, state and tribal agencies use it too, for decisions that protect life and property, safeguard the environment, advance science and education and support the economy. Businesses use it to improve logistics and investments, and a 2024 study put its total annual economic benefit at $25.6 billion, far above its costs. Landsat 8 and 9 image Earth's land every 8 days, and NASA and the USGS are working toward a 2031 launch of Landsat 10 to extend the more than 50-year record, the world's longest of Earth's land surface.

Sources

• U.S. Geological Survey: "Connecticut and Landsat," a fact sheet citing Pasquarella and others (2018), Worthley (2019), Murphy-Dunning (2020), Arnold and others (2020), Ballestero and others (2018) and Loomis and others (2024).