Annual National Land Cover Database (NLCD) Collection 1 Fractional Impervious Surface Conterminous United States

The Annual National Land Cover Database (NLCD) Fractional Impervious Surface product provides the fractional or percent surface area of a 30-meter map pixel that is covered with processed materials or structures (pavement, concrete, rooftops, and other constructed materials) that generate surface runoff. The majority of these materials are impervious to water, but many features that are not impervious like lawns and channelized ditches also contribute to surface runoff and water impairment.