Mapping Roadways at Landsat Scale
A satellite flying over this area northwest of Dallas, TX will capture a wide variety of urban and rural activity. The 80-odd square miles seen in the Landsat image on the left includes airports, dense urban centers, suburban and exurban neighborhoods, manufacturing and distribution centers, oil and gas production sites, lakes, forests, wetlands and more.
Mapping tools like the National Land Cover Database (NLCD) help scientists understand Landsat observations by turning them into pixel-by-pixel maps of specific features. The primary NLCD product sorts pixels into land cover classes, such as cultivated crops, pasture/hay, or deciduous forest, but NCLD also offers a host of secondary datasets that open up a wide range of potential scientific inquiry.
The right frame of this image pair shows a new dataset included in the latest NLCD release, NLCD 2016. The “Impervious Descriptor” data layer offers the first and only nationwide, Landsat-scale map of roadways and oil production facilities in the United States. The image above depicts on-the-ground conditions during the year 2016, but the data are also available for 2011, 2006, and 2001.
Used separately or in tandem with NLCD products like the Urban Imperviousness, the new dataset can be used to investigate questions on changes to the Nation’s transportation infrastructure and its impact on the wider ecosystem, wildlife habitat, human health, and more.
NLCD data is available at no cost to the public through the Multi-Resolution Land Characteristics Consortium (MRLC) website. The site also includes web-based map viewer that can be used to compare change across the U.S. from year to year using the full suite of NLCD products.