This book constitutes the refereed proceedings of the 4th International Conference on GeoSpatial Semantics, GeoS 2011, held in Brest, France, in May 2011. The 13 papers presented together with 1 invited talk were carefully reviewed and selected from 23 submissions. The papers focus on formal and semantic approaches, time and activity-based patterns, ontologies, as well as quality, conflicts and semantic integration. They are organized in topical sections on ontologies and gazetteers, activity-based and temporal issues, models, quality and semantic similarities, and retrieval and discovery methods.

GeoS 2009 was the third edition of the International Conference on Geospatial Semantics. It was held in Mexico City, December 3-4, 2009. Within the last years, geospatial semantics has become a prominent research ?eld in GIScience and related disciplines. It aims at exploring strategies, c- putational methods, and tools to support semantic interoperability, geographic information retrieval, and usability. Research on geospatial semantics is a m- tidisciplinary and heterogeneous ?eld, which combines approaches from the g- sciences with philosophy, linguistics, cognitive science, mathematics, and c- puterscience.WiththeincreasingpopularityoftheSemanticWebandespecially the advent of linked data, the need for semantic enablement of geospatial s- vices becomes even more pressing. In general, semantic interoperability plays a role if data are acquired in a di?erent context than they are ?nally used for. This is the case when shifting from the document Web to the data Web. The core idea of linked data is to make information contributed by various actors, with di?erent cultural backgrounds, and di?erent applications in mind available to the public. Understanding, matching, and translating between the concep- alizations underlying these data becomes a key challenge for future research on geospatial semantics. Thisvolumecontainsfullresearchpapers, whichwereselectedfromamong19 submissions received in response to the Call for Papers.Eachsubmission was - viewedbythreeorfourProgramCommitteemembersand10paperswerechosen for presentation. The papers focus on foundations of geo-semantics, the formal representationof geospatialdata, semantics-basedinformationretrieval and r- ommender systems, spatialqueryprocessing, aswellasgeo-ontologiesandapp- cations.Overall, adiversebodyofresearchwaspresentedcomingfrominstitutions in Austria, Germany, Mexico, The Netherlands, Spain, Taiwan, and the

This book constitutes the refereed proceedings of the Second International Conference on GeoSpatial Semantics, GeoS 2007, held in Mexico City, Mexico, in November 2007. The papers are organized in topical sections on models and languages for geo-ontologies, alignment and integration of geo-ontologies, ontology-based spatial information retrieval, formal representation for geospatial data, and integration of semantics into spatial query processing.