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Ground Sample Data for the Conterminous U.S. Land Cover Characteristics Database

出版	U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, 1999
URL	http://books.google.com.hk/books?id=GcNlSSfg8HIC&hl=&source=gbs_api
EBook	FULL_PUBLIC_DOMAIN

註釋Ground sample data were collected for a land cover database and raster map that portray 159 vegetation classes at 1 km2 resolution for the conterminous United States. Locations for 3,500 1 km2 ground sample plots were selected randomly across the United States. The number of plots representing each vegetation class was weighted by the proportionate coverage of each vegetation class. Field data collected for 2,560 of these plots included dominant vegetation species; coverage, height, and diameter estimates of major tree species; coverage, depth, and density estimates for shrubs and grasses; and photographs of the sample plots. These data were compared to vegetation labels assigned in the USGS, EROS Data Center's Land Cover Characteristics (LCC) database. The vegetation types were comparable in most cases, but the ground data provided labels ordered according to decreasing vegetation frequency. A formal accuracy assessment of the LCC map was not attempted. All data are available on a CD-ROM from the EROS Data Center.