The ACM SIGSPATIAL International Conferences on Advances in Geographic Information Systems (ACM SIGSPATIAL) are a series of symposia and workshops that began in 1993 with the aim of bringing together researchers, developers, users, and practitioners in relation to novel systems based on geo-spatial data and knowledge, and fostering interdisciplinary discussions and research in all aspects of geographic information systems. The conferences provide a forum for original research contributions covering all conceptual, design, and implementation aspects of geospatial data ranging from applications, user interfaces, and visualization to data storage and query processing and indexing. The conference is the premier annual event of the ACM Special Interest Group on Spatial Information.