The Historical Croplands Cover data set was developed to understand the consequences of historical changes in land use and land cover for ecosystem goods and services. In particular, this data set can be used to study how global changes in cultivated area have influenced climate, biogeochemical cycles, biodiversity, etc. This data set consists of two files at spatial resolutions of one and half degree, and can be used directly within spatially-explicit climate and biogeochemical models.
This is a gridded data set describing the fraction of each grid cell that is occupied by cultivated land from 1700 to 1992. Data layers are provided for every 50 years from 1700 to 1850, every 10 years from 1850 to 1980, and every year from 1986 to 1992.
There are two sources of global land cover and land use data. The most recent estimates were derived from satellite measurements, and are available in a spatially-explicit fashion for roughly the last 30 years. The other estimate is based on ground-based sources such as census statistics, land surveys, estimates by historical geographers, etc. These land inventory data are only available at the scale of political units, but have the advantage of being historical. Ramankutty and Foley (1998) derived a spatially-explicit data set of croplands in 1992 by synthesizing remotely-sensed land cover data with contemporary land inventory data. Furthermore, Ramankutty and Foley (1999) extended this data set into the past (back to 1700) using historical land inventory data.
The data set should only be used for continental-to-global scale analysis and modeling. The data set captures the broad patterns of cropland change over history, but not necessarily the fine details at local to regional scales - please check the data quality before using it at fine spatial scales. The quality of historical data for the Russian Federation is poor. The quality of data prior to 1850 is poor -- only continental-scale historical data were used for that period.
This data set is one of the products of the International Satellite Land-Surface Climatology Project, Initiative II (ISLSCP II) data collection which contains 50 global time series data sets for the ten-year period 1986 to 1995. A complete description of the data, their derivation, acknowledgements, and references provided by the ISLSCP II Data Management Staff is included with this data set as a companion file named 1_historic_cropland_doc.pdf.
ISLSCP II is a consistent collection of data sets that were compiled from existing data sources and algorithms, and were designed to satisfy the needs of modelers and investigators of the global carbon, water and energy cycle. The data were acquired from a number of U.S. and international agencies, universities, and institutions. The data and documentation have undergone two peer reviews.
ISLSCP is one of several projects of Global Energy and Water Cycle Experiment (GEWEX) [http://www.gewex.org/] and has the lead role in addressing land-atmosphere interactions -- process modeling, data retrieval algorithms, field experiment design and execution, and the development of global data sets.
Cite this data set as follows:
Ramankutty, N. and J.A. Foley. 2010. ISLSCP II Historical Croplands Cover, 1700-1992. In Hall, Forest G., G. Collatz, B. Meeson, S. Los, E. Brown de Colstoun, and D. Landis (eds.). ISLSCP Initiative II Collection. Data set. Available on-line [http://daac.ornl.gov/] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. doi:10.3334/ORNLDAAC/966
The archived data sets for ISLSCP II have been organized by categories. This data set is in the vegetation category--a collection of vegetation and albedo data sets.
Data Set Spatial Extent: Global gridded
Westernmost Longitude: -180 W
Easternmost Longitude: 180 E
Northernmost Latitude: 90 N
Southernmost Latitude: -90 S
Data Set Spatial Resolution: half and one degree in both latitude and longitude
Data Set Temporal Extent: from 1700 to 1992
Data File Format
All of the data files in each data set within the ISLSCP Initiative II data collection are in ESRI ASCII GRID format for ArcInfo. The file format consists of numerical fields of varying length, which are delimited by a single space and arranged in columns and rows.
The data files have been combined according to spatial resolution: 1 degree and half degree, respectively.
The names of the individual files in each zip file above use the following naming convention:
historic_cropland_hd_YYYY.asc -- where hd stands for a half degree spatial resolution and YYYY is the year from 1700 to 1992. The files in this data set all contain 720 columns by 360 rows.
historic_cropland_1d_YYYY.asc -- where 1d stands for a half degree spatial resolution and YYYY is the year from 1700 to 1992. The files in this data set all contain 360 columns by 180 rows.
historic_cropland_hd_chngmp.asc-- shows the differences between the original hd degree land/water mask and the hd degree land/water mask used in this collection.
Data file naming conventions are described in the 0_historic_cropland_readme.txt
Ramankutty, N., and J.A.
Foley, Characterizing patterns of global land use: An analysis of
global croplands data, Global Biogeochemical Cycles, 12, 667-685, 1998. doi:10.1029/98GB02512
Ramankutty, N., and J.A.
Foley, Estimating historical changes in global land cover: Croplands
from 1700 to 1992, Global Biogeochemical Cycles, 13, 997-1027, 1999. doi:10.1029/1999GB900046
These data are available through the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC) [http://daac.ornl.gov].
Telephone: +1 (865) 241-3952