Historical Croplands Dataset, 1700-1992

Navin Ramankutty and Jonathan Foley, from the Center for Sustainability and the Global Environment (SAGE), part of the Gaylord Nelson Institute for Environmental Studies at the University of Wisconsin - Madison, have developed a global, spatially-explicit data set of reconstructed historical croplands from 1700 to 1992. The method for historical reconstruction uses a simple algorithm which links contemporary satellite data and historical cropland inventory data. A spatially-explicit croplands data set for 1992 was first derived by calibrating a satellite-derived land cover classification data set against cropland inventory data for 1992. This data set was then used within a simple land cover change model, along with historical cropland inventory data, to derive spatially-explicit maps of historical croplands. The data set is restricted to a representation of permanent croplands (i.e., excluding shifting cultivation), which follows the United Nations Food and Agriculture Organization (FAO) definition of arable lands and permanent crops.

The data are available for downloading from the SAGE website at [http://www.sage.wisc.edu/pages/datamodels.html]. The data are provided at 0.5 degree resolution in NetCDF format. Accompanying the data is a README file containing more information on data format. The 0.5 degree file contains annual data. Data are also available at 5 min resolution in ArcINFO ASCII format for selected periods at the SAGE website (see Data Set Links, below).

More information on these data can be found in: Ramankutty, N. and J.A. Foley. 1999. Estimating historical changes in global land cover: Croplands from 1700 to 1992. Global Biogeochemical Cycles 13(4):997-1027. See Abstract at [http://www.sage.wisc.edu/pubs/abstracts/ramankuttyGBC1999.html].