Geo-Wiki.org: Crowdsourcing to improve global land cover data
In our book The GIS Guide to Public Domain Data, we spend quite a bit of time discussing crowdsourcing, and rightly so: Over the past few years, crowdsourcing has become a viable way not only to collect data, but also to verify and update existing data. Reasons include budget constraints in those agencies that provide data and the subsequent need for field verification, a growing recognition that decisions based on spatial data are only as beneficial as the accuracy of the data sets themselves, the rapid expansion of citizen science, and growth in the number and variety of mobile and web-GIS tools that enable citizen scientists to contribute to the global community.
Examples of verifying and updating existing data are numerous, and a noteworthy one is from a group of researchers at the International Institute for Applied Systems Analysis (IIASA) in Austria who lead an effort to improve global land cover/land use data. This effort, http://www.geo-wiki.org, verifies three land cover data sets, including GlobCover from the ESA, MODIS from NASA, and GLC 2000 from the IES Global Environment Monitoring Unit, through knowledge and photographs from people local to specific areas.
Besides an improvement of the data and, it is hoped, in the decisions based on those data, some of these efforts feature innovative projects that provide benefit to local people. For example, Geo-Wiki users were asked to identify the presence of cultivated land and settlements in samples in Ethiopia in a “hackathon” associated with USAID in an effort to improve local food security.
More information can be found on the Geo-Wiki site and in an article describing the project.