The U.S. Geological Survey (USGS) developed a land-use and land-cover classification system for use with sensor data in the mod-1970's (Anderson and others, 1976). This system, known as the Anderson classification system, used a hierarchical structure. The broadest level, Level I, divided land use into nine categories, whereas Level II subdivided each Level I category into more descriptive land uses. Subsequently, the USGS Geographic Information Retrieval and Analysis System (GIRASA) was implemented, using NASA high-altitude aerial photocoverage to produce land-use and land-cover maps for the United States (Mitchell and others, 1977).
The current procedures used to generate consistent, accurate, and current land-use and land-cover maps for intermediate scales (spatial resolution of 1 hectare or less) in the United States are based on satellite imagery (Vogelmann and others, 1998a). Typically, Landsat Thematic Mapper imagery, aerial photographs, and ancillary layers, such as Digital Elevation Models, wetlands inventory maps, and other datasets are used in mapping land use. Generally, the land-use category for each pixel in an image is assigned using a relation between reflectance value and land use for locations where land use is known or determined from other ancillary datasets.
Mitchell, W.B., Gutpill, S.C., Anderson, K.E., Fegeas, R.G., and Hallam, C.A., 1977, GIRAS: A Geographical Information Retrieval and Analysis System for handling land use and land cover data: U.S. Geological Survey Professional Paper 1059, 16 p.
Vogelmann, J.E., Sohl, T.L., Campbell, P.V., and Shaw, D.M., 1998a, Regional land cover characterization using Landsat Thematic Mapper data and ancillary data sources, Environmental Monitoring and Assessment, v. 51, p. 415-442.