Semantic enrichment of Volunteered Geographic Information using Linked Data: a use case scenario for disaster management

Abstract

Web 2.0 data deluge provoked by the development of collaborative tools has affected numerous domains. In the context of the crowdsourcing of geographic information, the concept of Volunteered Geographic Information (VGI) has emerged. However, the quality and usability of VGI is a subject of a debate. Data often comes unstructured with unknown accuracy and lacking reliability. Semantic integration of VGI with relevant entities in the Linked Open Data (LOD) cloud has been seen as a remedy to overcome weakness of a crowdsourced data. The LOD cloud makes it possible to semantically enrich unstructured user-generated content with structured information presented in the LOD resources. This thesis questions to what extent the Linked Open Data cloud can help to semantically enrich volunteered geographic information in order to better answer queries in the context of crisis and disaster relief operations. Data produced by the Ushahidi project during the Chilean earthquake of 2011 has been chosen as an example of a disaster related VGI. In general, the work implied a construction of the proof of concept. The first two steps have included a conversion of the data into the Resource Description Framework (RDF) using vocabularies and establishing of semantic links to relevant LOD entities. The use of the Management of a Crisis vocabulary has increased semantic interoperability of the original data. Semantic enrichment achieved via established links has helped to overcome ambiguous georeferencing of the data thus allowing a robust spatial dimension to the data. Emerged spatial capabilities made it possible to access data entities using spatial queries. In turn, the latter provided a straightforward mechanism for data retrieval, for instance, from DBpedia. The work has shown that the LOD cloud can be perceived as a giant informational skeleton. Scattered and disconnected blobs of unstructured data, being attached to this skeleton, acquire an integrated dataspace where standardized methods of data access and manipulation can be used. Despite of the fact, the work dealt with the disaster-related VGI, the demonstrated approach can be applied to any VGI.