HR: 11:20h
AN: B51F-05    [PDF]
TI: Cropland and Population Changes Through 208 Years in the Conterminous United States
AU: * Bliss, N B
EM: bliss@usgs.gov
AF: SAIC, USGS EROS Data Center, Sioux Falls, SD 57198 United States
AU: Waisanen, P J
EM: waisanen@usgs.gov
AF: USGS, USGS EROS Data Center, Sioux Falls, SD 57198 United States
AB: Broad patterns of human influence on the landscape can be seen in our data set of population size and area of cropland within each county. Our purpose was to provide data on the timing of land conversion as an input to dynamic models of the carbon cycle, although a wide variety of applications exist in the physical, biological, and social sciences. We used U.S. Census data to reconstruct a history of land disturbance for the conterminous United States. The population time series begins with the first census in 1790, and continues at 10 year intervals through the 1990 census. The cropland time series begins in 1850, with data added at 10 and 5 year intervals through 1997. We have used the population data to extrapolate the cropland time series back to 1790. Spatial data sets of the historical county boundaries were used for linking to the census tables, and modern county boundaries were used for visualizing and analyzing the time series and for data distribution. The data set has more spatial detail than previously available compilations. The patterns of agricultural development reflect the influences of climate, soil productivity, increases in population size, variations in the general economy, governmental policies, and technological changes in the energy, transportation, and agricultural sectors. There was a peak in the area of cropland in 1940, with distinct regional trends and patterns.
DE: 0400 Biogeosciences
DE: 1615 Biogeochemical processes (4805)
DE: 6334 Regional planning
DE: 9350 North America
SC: Biogeosciences [B]
MN: 2003 Fall Meeting