Multi-Resolution Land Characterization 2001 (MRLC 2001) is a second-generation Federal consortium designed to create an updated pool of nation-wide Landsat 5 and 7 imagery and derive a second-generation National Land Cover Database (NLCD 2001
IntroductionConsistent, relevant land cover information at a national scale provides data for a wide variety of geographical analysis and applications. In the last decade, a major provider of land cover information within the Federal government has been the Multi-Resolution Land Characteristics Consortium (MRLC). The MRLC was originally formed in 1993, to meet the needs of several Federal agencies (U.S. Geological Survey (USGS), Environmental Protection Agency (EPA), National Oceanic and Atmospheric Administration (NOAA), and U.S. Forest Service (USFS)) for Landsat 5 imagery and land cover information (Loveland and Shaw 1996). One of the products of this consortium was the completion of a successful mapping of the conterminous United States into the National Land Cover Dataset (NLCD 1992) (NLCD 2001), which is being generated across all 50 States and Puerto Rico using Landsat imagery and ancillary data.The completion of the initial NLCD 1992 (Vogelmann et al., 2001A) created a TM pixel scale (30 m) data layer over the conterminous United States with approximately nine billion pixels. During the five years of mapping required to complete this prototype product, many lessons were learned about quality of source data, objectivity of methods, and flexibility of products. This feedback, coupled with new MRLC 2001 member requirements, provided the guiding principles and research direction that culminated in the NLCD 2001 design. Principles included: (a) develop land cover products flexible enough for multiple users, (b) provide users with increased access to intermediate database products and derivatives, enabling local application, (c) develop methods that are as objective, consistent, and repeatable as possible, resulting in standardized land cover products that can be quickly updated, (d) constrain methods to those that are intuitive, simple, efficient, and transferable to others, and (e) ensure that the design of a second-generation land cover product maintains reasonable compatibility with NLCD 1992.The NLCD 2001 foundation is a database approach to land cover (defined as multiple interlinked data layers that are useful either as individual components or in synergistic groupings) which builds upon past USGS database designs such as the global land cover database (Brown et al., 1999, Loveland et al., 2001, while providing the land cover data necessary to meet the vision of the The National Map (USGS 2001) currently being created by the USGS for the United States.
PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING
July 2004829 SAIC Corporation, USGS/EROS Data Center, Sioux Falls, SD 57198 (homer@usgs.gov).