This book lays a foundation on the conceptual, theoretical, system-development, and application perspectives of intelligent spatial decision support systems. Departing from conventional approaches that only concentrate on model-data integration, the author places emphasis on the artificial intelligence approach to spatial decision support. In addition to the employment of models, it is argued that systems that can perform commonsense reasoning are of paramount importance in spatial decision support. Fundamental concepts of knowledge representation and inference in spatial decision support systems are investigated. Both the symbolic and distributed approaches are examined. Automatic knowledge acquisition by genetic algorithms is discussed.