As the world’s population grows, the amount of land available for farming is becoming a major concern. Increasing competition for land is springing up among growers, developers, and many others. This makes it critical to determine how much total land is available for farming across the globe but that completing this task is nearly impossible. The good news, though, is that two new maps are helping to overcome obstacles for gathering information on arable land.
In January 2015, two new maps were released in the Global Change Biology journal, and they provide detailed information about the size and location of global farmland. The first map displays global cropland percentages for the year 2005 at a resolution of one kilometer. The International Food Policy Research Institute (IFPRI) developed this particular map along with the International Institute for Applied Systems Analysis (IIASA). Many other organizations and institutes contributed data sources for the map as well.
This global cropland map is unique in that it is more accurate than any other preceding ones. The reason for this is that researchers used a hybrid approach that combined existing maps in order to create a more integrated product. They reasoned that wherever other maps agreed that farmland existed in a location, the higher the likelihood farmland was actually present. It is particularly difficult to determine the location of farmland in developing countries because of the abundance of smaller plots.
The other map is special in that it displays the size of fields being utilized for agriculture. Previous estimates concluded that the size of global cropland was between 1.22 billion and 1.71 billion hectares, a sizeable difference. As the first of its kind, the field map offers a new way to monitor global agriculture in that the growth of field sizes in certain locations could signal a trend toward development and mechanization.
The field map is also significant in that it shows the different approaches to farming around the globe. For example, small fields tend to dominate the landscape in the farming areas of India, Southeast Asia, China, and Africa. Medium and large fields make up North America, central South America, Europe, and Australia.
The information gathered to produce these two maps came from a variety of sources. These sources included regional maps, satellite images, video, and geotagged photos. Still, the task would have been overwhelming for scientists without crowdsourcing. A team of volunteer citizen scientists logged onto IIASA’s Geo-Wiki project on their computers and phones. They played an online game to determine whether or not an image contained cropland, and in return for their participation, were entered into weekly prize drawings.
The ultimate hope is that these two new maps will make it easier to get accurate counts of the world’s land available for farming. There could be other uses as well. The global farmland map could become a reference map for climate modelers while the field map is unique in that no other global map of its type currently exists. Information on cropland is significant to policymakers for developing plans, and knowing where farmland exists is critical for food security in an ever changing world.
The geospatial data from the Global Cropland and Global Field Size Maps can be downloaded from the Geo-Wiki Web site (registration required).
“Finding Farmland: New Maps Offer a Clearer View of Global Agriculture.” http://www.eurekalert.org/pub_releases/2015-01/iifa-ffn011415.php
“New Farm Maps Offer In-Depth Picture of Global Agriculture.” http://www.livescience.com/49497-farming-tracked-from-space.html