Read Me First

Notes

• The datasets are 5 arc-minute (as known as 10 km grid cells) pixel-level estimates of crop area, production and yield. While the datasets are consistent with actual census data at aggregate levels (e.g. country, state, counties), the pixel level distributions are modeled results which may differ from the actual condition at the farm level. We recommend they be used for regional and global analysis, and use caution when used in country or sub-national studies.
• Each zip file also contains a copy of the license agreement between you and HarvestChoice which you agreed to in order to access the data.
• Version 3.0.2 (Version 3 Release 2; April 5, 2010) fixed the incorrect xllcorner and yllcorner values included in 3.0.1 (Version 3 Release 1).

Data Files

Once you complete and submit the above information, you’ll receive an email with your password and URL to access the SPAM data files. There are following four folders and files inside of the file download section:

1. Grid Cell ID: 5 arc-minute cell ID surface based on the HarvestChoice Cell ID Databases (HCID). This layer can be used to map the raw SPAM data tables (CELL5M column) using GIS software.
2. Maps: Image files (PNG format) for a selected crops/variables/input systems. Refer to the folder and file names to identify the content of each map.
3. Raster (ESRI ASCII): Five zip files contains the SPAM data results in the ESRI grid ASCII  format, a non-proprietary format widely being used in many GIS software.
   • spam2000v3r2.zip: This package includes all data files.
   • spam2000v3r2_harvested-area.zip: This package include harvested area data files for all crops and input systems.
   • spam2000v3r2_physical-area.zip: This package include physical area data files for all crops and input systems.
   • spam2000v3r2_production.zip: This package include production data files for all crops and input systems.
   • spam2000v3r2_yield.zip: This package include yield data files for all crops and input systems.
4. Raw Data Table (DBF and ASCII): Two zip files contain the complete set of SPAM results in ASCII text (tab-delimited) and DBF formats including all SPAM results.
   • Variables: The tables are divided by variable, or record type; these are identified by “REC_TYPE” column: P – Physical area (ha), H – Harvested area (ha), R – pRoduction (ton), and Y – Yield (kg/ha)
   • Input Systems: Each crop is divided into 3 sub-systems: I – irrigated (“I”), H – rainfed high-input/commercial (“H”), and L – rainfed low-input/ subsistence (“L”). For each input system, results are stored by columns and in total. So the column heading of “RICE” refers to the total rice physical area (if rec_type=”P”), total harvested area (“H”) or total production (“R”). “RICE-H” refers to high-input rainfed physical area (if rec_type=”P”), high-input rainfed harvested area (“H”) or high-input rainfed production (“R”) and so on for each of the 20 crops. By definition, the total column (e.g. “RICE”) should be equal to the sum of the sub-systems, (e.g. “RICE-H”,”RICE-L”,”RICE-I”) for each row.
   • Crops: The 20 crops that SPAM models are: wheat, rice, maize, barley, millet, sorghum, potato, sweet potato, cassava and yams, plantain and banana, soybean, dry beans, other pulse, sugar cane, sugar beets, coffee, cotton, other fibres, groundnuts, and other oil crops.  The other crops are always zero values except in the physical area table where the value for [other crops] is estimated by subtracting the sum of the above 20 crops from total cropland area for each pixel.

Citation

• Datasets: You, L., S.Crespo, Z. Guo, J. Koo, W. Ojo, K. Sebastian, M.T. Tenorio, S. Wood, U. Wood-Sichra. Spatial Produciton Allocation Model (SPAM) 2000 Version 3 Release 2. http://MapSPAM.info (Accessed _____)
• Paper: You, L., S. Wood, U. Wood-Sichra. 2006. Generating global crop maps: from census to grid. Selected paper, IAAE (International Association of Agricultural Economists) Annual Conference, Gold Coast, Australia.

Question?

Please feel free to ask any question on the SPAM data format and how to use it in your research.