MRLC: An Innovative Partnership for National Environmental Assessment
MRLC is a successful example of a bottom-up, E-Government initiative where several federal agencies have collaborated in a collegial environment to provide digital land-cover and ancillary data to the nation. A host of Federal Institutions participate in MRLC including U.S. Geological Survey (USGS), Environmental Protection Agency (EPA), National Oceanic and Atmospheric Administration (NOAA) and the U.S. Forest Service (USFS). Later joining the consortium were the National Atmospheric and Space Administration (NASA) and the Bureau of Land Management (BLM), National Park Service, U.S. Fish and Wildlife Service (USFWS), National Aeronautics and Space Administration (NASA), Office of Surface Mining (OSM), and the Natural Resource Conservation Service (NRCS).
The MRLC Consortium produces four different land-cover databases. The mapping efforts are not duplicative: all three use the same basic methods and data, and mapping done in one project supports the other two. The primary source of data for all three mapping efforts is Landsat (TM).
- The National Land Cover Database (NLCD) provides land-cover data for 1992, 2001, and change between the two dates (under development) for the United States and Puerto Rico. Land-cover products outside the conterminous Unites States are only available for 2001.
- The Coast Change Analysis Program (C-CAP) provides land-cover and land-cover change data for the coastal portions of the United States. Land-cover change, particularly as they affect coastal wetland resources, is an explicit objective of C-CAP.
- The Gap Analysis Project (GAP) provides habitat maps and combines these with wildlife models to determine where there are "gaps" in the network of U.S. conservation lands.
- Landscape Fire and Resource Management (LANDFIRE) provides vegetation and wildland fuel maps, and information on fire regimes for the U.S.
MRLC started in the mid1990s due to the escalating cost of acquiring satellite imagery (Goward 1989) to meet agency missions. MRLC was originally envisioned as a federal Landsat data purchasing program. The concept of pooling resources to reduce individual costs applies to land-cover mapping as well. MRLC has effectively converted the "power of the purse" concept to an operational paradigm for producing complementary national land-cover data and related information.