HarvestChoice Releases Updated Meso-Scale Cropping System Data

Global Rainfed and Irrigated Crop Distribution for 2000: SPAM version 3 (release 2*)

Large gaps exist in our knowledge of the geographic distribution of crops and the spatial patterns of crop performance, particularly for poorer, less accessible regions of the world. In an effort to fill these gaps and, in turn, increase the effectiveness of agricultural development policy and investment initiatives, HarvestChoice recently released its latest Global Rainfed and Irrigated Crop Distribution data product, generated using the Spatial Production Allocation Model (SPAM). These most recent SPAM results (version 3; release 2*) represent the last planned major update of the global crop distribution model for the year 2000. This model has undergone, and continues to undergo, a significant validation and feedback process involving centers from the Consultative Group on International Agricultural Research (CGIAR) and other collaborators.

 *Note: Version 3 release 2 contains the same data as version 3 release 1 but corrects the coordinates in the downloadable ascii files. The ascii files for Version 3 release 1 contained incorrect coordinates for the lower left x and y corners resulting in a shift the SPAM results by 1/2 a cell (0.04167dd or approximately 5km at the equator). Specific information on how to correct this shift if you have already downloaded release 1 is available in Known Issues. Additionally, the corrected data, version 3 release 2, are available for download. The release 1 data have been removed from the download site.

SPAM 2000 version 3 is a meso-scale model that provides estimates of crop production, area, and yield by 10x10km grid cells for 20 major crops that together account for almost 90 percent of the world’s total harvested area. Additionally, to support more in-depth analysis of the relationship between crop production, technological opportunities for enhanced productivity, ecosystem services, and human well-being, the SPAM results include assessments of the distribution and performance of three categories of production systems for each crop: irrigated, high-input/commercial rainfed, and low-input/subsistence rainfed.

SPAM takes into account a broad range of data in the process of downscaling sub-national production statistical or survey data to individual grid cells. This includes:  interpreted satellite imagery on the extent and area intensity of rainfed and irrigated crop systems and other land use/cover data, crop prices, population density, biophysical assessments of location-specific crop “suitability”, and time of travel from farms and local markets to urban centers.

In addition to the SPAM results, HarvestChoice also generates and publishes compatible global and regional datasets across a range of natural resource, production, consumption, market, and rural welfare themes as part of its mandate to generate strategic policy and investment advice targeted, in particular, to Sub-Saharan Africa, but with a global perspective on the importance of investment targeting, inter-regional technology spillover, and trade opportunities.

Preparations are under way for the first release of SPAM 2005, currently slated for late 2010.