Harvesting geospatial knowledge from social metadata

Up-to-date geospatial information can help crisis management community to coordinate its response. In addition to data that is created and curated by experts, there is an abundance of user-generated, user-curated data on Social Web sites such as Flickr, Delicious, and Google Earth, that can be used to harvest knowledge to solve real-world problems. User-generated, or social, metadata can be used to learn concepts and relations between them that can improve information discovery, and data integration and management. We describe a method that aggregates social metadata created by thousands of users of the social photo-sharing site Flickr to learn geospatial concepts and relations. Our method leverages geotagged data to represent and reason about places. We evaluate learned geospatial relations by comparing them to a reference ontology provided by GeoNames.org. We show that our approach achieves good performance and also learns useful information that does not appear in the reference ontology.