This book constitutes the refereed proceedings of the Second International Conference on Geographic Information Science, GIScience 2002, held in Boulder, Colorado, USA in September 2002. The 24 revised full papers presented were carefully reviewed and selected from 64 paper submissions. Among the topics addressed are Voronoi diagram representation, geospacial database design, vector data transmission, geographic information retrieval, geo-ontologies, relative motion analysis, Web-based maps information retrieval, spatial pattern recognition, environmental decision support systems, multi-scale spatial databases, mobile journey planning, searching geographical data, indexing, terrain modeling, spatial allocation, distributed geographic internet information systems, and spatio-thematic information programming.