SPAM 2010: Updated global crop data aid in food policy decisions

Knowing where in the world individual crops are cultivated, their production patterns, and whether they are irrigated or rain fed are essential components for ensuring adequate, sustainable food production and safeguarding food security. Yet this critical data is often inadequate or non-existent, leaving policymakers unable to formulate the best policies to help farmers improve yields, access subsidized fertilizers, and get their products to markets.

A newly updated interactive website seeks to help solve this problem by providing spatially disaggregated crop production estimates for 42 crops around the globe. Developed by the International Food Policy Research Institute (IFPRI) and the International Institute for Applied Systems Analysis (IIASA), the website, called Spatial Production Allocation Model (SPAM) at www.mapspam.info, pinpoints the production of crops—such as rice, cassava, potatoes, wheat and maize—down to the pixel level at a resolution of five minutes (about ten kilometers at the equator). First launched in 2008 using data from 2000, and later updated for SPAM 2005, the website has been recently updated with new data from 2010, is more interactive, and includes a map gallery and data center. 

Using a variety of inputs, SPAM uses a cross-entropy approach to make plausible estimates of crop distribution within disaggregated units. Moving the data from coarser units such as countries and sub-national provinces, to finer units such as grid cells, reveals spatial patterns of crop performance, creating a global grid-scape at the confluence between geography and agricultural production systems.

The result is highly-accurate global data that can aid policymakers seeking to ensure that local food production is optimized to meet demand, that farmers get the highest possible yields, and that food is grown sustainably. Improving spatial understanding of crop production systems allows policymakers and donors to better target agricultural and rural development policies and investments, increasing food security and growth with minimal environmental impacts. The maps can be overlaid with other geospatial datasets to help with other aspects of food security as well, such as crop productivity, climate change, ecosystem services, and social welfare.

“Even with the latest remote sensing technologies, identifying different types of crops cultivated on the ground is still a very challenging task,” said Liangzhi You, a Senior Research Fellow at IFPRI and Harvest partner, who led the methodology and modeling that produced the data. Dr. You has noted there will be more updates to come for SPAM 2010, including major versions at intervals and minor occasional updates over the next two years. These updates depend on the feedback received from users, reflecting the development of a malleable system of data.  

The new website includes maps that were produced using satellite images and then fine-tuned by a global crop mapping community on the ground, who meticulously reviewed the remote sensing imagery to ensure their accuracy and make changes. The work was done in collaboration with other CGIAR centers and many local collaborators. The acquisition of sub-national crop statistics which are accurate and consistent is some of the most labor-intensive work.

Researchers at IFPRI and IIASA have said they expect to be able to produce even more detailed maps in the future by relying on better data and technology. “It is likely that we will drastically improve such maps in the near future using imagery with higher spatial and temporal resolution as well as a richer in-situ database from information on the ground using mobile devices and local knowledge,” said Steffen Fritz, Deputy Program Director of the Ecosystem Services and Management Program at IIASA and Harvest partner, who contributes the cropland mapping for SPAM.

For more information and data download options, please visit the MapSPAM website. Funding support was provided by CGIAR Platform for Big Data in Agriculture, CGIAR Research Program on Policies, Institutions, and Markets (PIM), NASA Harvest, and USAID Feed the Future Innovation Lab for Small Scale Irrigation.