The Alaska data amount to the most up-to-date and comprehensive land cover map ever produced for the largest U.S. state in the Union, offering critical insight into some of North America’s most rapidly- and dramatically-changing landscapes.

The release for the Last Frontier dovetails with last year’s publication of NLCD 2016 for the conterminous U.S. (CONUS). The new maps represent a robust upgrade to a satellite-based dataset that’s been relied upon for decades in the study of ecosystem status and health, spatial patterns of biodiversity, indications of climate change, and best practices in land management.

As with NLCD 2016’s CONUS data products, the Alaska land cover maps depict 15 years of change, from 2001-2016.

NLCD is built using data from the USGS Landsat series of satellites. Each 30-meter plot of ground in the country, for each mapped year, is assigned a land cover class – e.g. cultivated cropland, high-density urban, woody wetlands or deciduous forest. Comparing the years across the decade and a half of newly-available data enables users to better understand the trajectory of land change patterns and processes.

NLCD 2016 products include 20 classes of land cover for Alaska, as well as a separate product that defines impervious surfaces in urban areas (usually composed of concrete, asphalt, stone, and metal — widely recognized as a key indicator of environmental quality in urban areas).

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These data are especially valuable in polar and subpolar regions, which are changing at faster clip than the rest of the planet. In Alaska, NLCD data can help researchers track and understand changes such as forest recovery and regrowth after wide-scale wildfire activity and shifts in grassland and shrubland growth patterns.

As with the Lower 48, NLCD 2016 products for Alaska include the land cover data and data on impervious surfaces, including a impervious descriptor layer that identifies roads, energy development sites and other urban features.

NLCD products are constructed by a 10-member federal interagency known as the Multi‑Resolution Land Characteristics Consortium (MRLC). The ongoing 20-year collaboration demonstrates an exemplary model of cooperation among government entities that combine resources to efficiently provide digital land cover for the Nation. Their teamwork in producing the NLCD not only significantly advances land cover science, but saves taxpayers money.

The range and spatial accuracy of NLCD information have made it essential to thousands of users, and enables managers of public and private lands, urban planners, agricultural experts, and scientists across a wide range of disciplines to identify land surface characteristics and patterns of change. The data inform a variety of investigations, from monitoring forests to modeling water runoff in urban areas.

Follow this link for more information on NLCD, and to download NLCD data free of charge.