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MRLC-LAND COVER MAPPING, ACCURACY ASSESSMENT AND APPLICATION RESEARCH
Impact/Purpose:
The objective of this task is to produce land-cover and related products that are needed to meet Annual Performance Goals (APG) under GPRA Goals Clean Air, Clean Water, and Healthy and Safe Communities, and to meet the critical needs of EPA Regional Offices.
Description:
The National Land Cover Database (NLCD), produced by the Multi-Resolution Land Characteristics (MRLC) provides consistently classified land-cover and ancillary data for the United States. These data support many of the modeling and monitoring efforts related to GPRA goals of Clean Air, Clean Water, and Healthy Communities and Ecosystems. The first mapping effort was completed for the conterminous United States in 2001 using Landsat TM data acquired on a target year of 1992. This product is referred to as NLCD 1992. A supporting national quality assurance evaluation (accuracy assessment) was completed and published in 2004.
In FY02, the MRLC Consortium began planning for a second round of mapping. This mapping effort was initiated in FY03. Substantial improvements were included in the second mapping effort. The second mapping effort, referred to as NLCD 2001, is now a database that includes: 1) land cover, 2) impervious surface, and 3) canopy density, 4) DEM, 5) Tasselled Cap image data, 6) confidence maps for the land-cover classification, and 7) "historical" data (node maps) that permit the tracing of each pixel from spectral value to land-cover class. The Landsat data for NLCD 2001 was acquired on a target year of 2001.
Land-cover change data are needed to determine the impact of a dynamically changing earth surface (e.g., urbanization) on Clean Air, Clean Water, and Healthy Communities and Ecosystems. The NLCD 2001 and NLCD 1992 land-cover classifcations are compatible, supporting change detection. Comparison of NLCD 1992 and NLCD2001 can be used to estimate land-cover change at a simple classification detail (e.g., Water, Urban, Agriculture, Forest, Barren, Wetland, Grass/shrub).