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SCALING-UP INFORMATION IN LAND-COVER DATA FOR LARGE-SCALE ENVIRONMENTAL ASSESSMENTS
Citation:
Wickham, J D. SCALING-UP INFORMATION IN LAND-COVER DATA FOR LARGE-SCALE ENVIRONMENTAL ASSESSMENTS. Presented at Forest-Related Activities and Integrated Assessment Approaches in the European Union and the United States Joint Research Centre, Ispra, Italy, December 10, 2003.
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 NLCD project provides national-scope land-cover data for the conterminous United States. The first land-cover data set was completed in 2000, and the continuing need for recent land-cover information has motivated continuation of the project to provide current and change information on land cover for regional- to national-scale applications. As with any project, the lessons learned NLCD's first implementation have uncovered new methodological approaches that are anticipated to improve future land-cover products. The majority of these are scaled approaches to land-cover mapping, and include: I ) "smart" scene selection using seasonal (temporal) NDVI to select Landsat TM data; 2) regression-based land-cover "derivatives" ( e.g., impervious surface) for input into the land-cover mapping process and database development; 3) rule-based(e.g., CART) land-cover mapping, and 4) mapping by ecoregion- like mapping zone to improve spectral separation of classes and improve edge-matching. The land-cover data support development of several indicators for regional- to national-scale environmental assessments. Examples of indicators for regional- to national-scale environmental assessments discussed include nitrogen and phosphorus export risk, landscape unit identification and delineation, and change detection.