![]() ![]() A land use/cover file is a digital vector file containing 26 land use/cover categories. Placement of dots utilized land use/cover files, weighting factors, customized statistical algorithms, and GIS software to allocate and randomly place dots within geographic areas. The traditional dot map symbolizes (positive) data with blue dots. The pattern and number of dots within a geographic area reveal the density of the phenomenon. The pattern of distributed dots reflects the general locations where the phenomenon was most likely to occur. The dot-density maps portray quantitative data as a dot which represents a number of the phenomenon found within the boundary of a geographic area. The maps were projected using Albers Equal Area Conic projection. and Hawaii were mapped at a scale of 1:21,000,000 and Alaska used a map scale of 1:63,000,000. Department of Agriculture, Natural Resources Conservation Service, National Resources Inventory, 2007). Department of Agriculture, Forest Service, 2016), and randomly distributed point data of Non-Federal Grazing Land (U.S. Forest Service grazing allotment polygons (U.S. Department of the Interior, BLM, 2018), U.S. Geological Survey, 2008), Irrigated Lands from Remote Sensing (Mutlu Ozdogan, University of Wisconsin, Center for Sustainability and the Global Environment, 2001), Bureau of Land Management (BLM) national grazing allotment polygons (U.S. ![]() The predominant land use/cover type for each PSU was determined from several sources: a 5-year composite of the NASS Cropland Data Layers for years 2008 – 2012, Moderate Resolution Imaging Spectroradiometer (MODIS) Irrigated Agriculture Dataset for the United States (Earth Resources Observation and Science Center, U.S. NASS created a new land use/cover boundary file based on NASS’ Primary Sampling Unit (PSU) boundaries. The statistical data and geographic areas were identified by Federal Information Processing Standards (FIPS) codes that allowed for a 1-to-1 correspondence between the data and the geographic area. NASS modified the county boundary file to show the county-level geographic areas for which agriculture census statistics are reported. Census Bureau provided a generalized county boundary file and a county-level land area/perimeter data file. Colors for the maps were selected with the assistance of ColorBrewer, an online tool for selecting map color schemes. ![]() The software also executed other cartographic functions, including: assigning symbology to represent the data randomly placing dots creating and positioning map titles, legends and notes and outputting individual maps to digital image files. The customized software performed statistical calculations to allocate the number of dots for a geographic area. The system utilized agricultural statistical data files, geographic area boundary files, land use/cover boundary files, map parameter data files, and customized GIS and statistical software to produce thematic dot-density maps. NASS developed an automated map production system to generate digital map files based on statistical data from the 2017 Census of Agriculture. Geographic information system (GIS) and desktop publishing technologies were used in the production of these thematic maps. Vegetables, Acres Harvested for Sale: 2017Īccess county-level data and maps, as well as the entire data set, at the 2017 Ag Census Web Maps. Soybeans for Beans, Harvested Acres: 2017 Number of Broilers and Other Meat-Type Chickens Sold: 2017Īll Wheat for Grain, Harvested Acres: 2017 ![]() 2017 Census of Agriculture Ag Atlas Maps are available for the following topics: 2017 Ag Atlas Maps Map # ![]()
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