Research on the formalization description of user requirement in GIS demand-based services

The formalization description of user needs is one of key issues in GIS on-demand services. A number of user demand documents is collected, the paper analyzes them in semantics and geometric aspects, discusses something reflected in the demands, which is about datasets selection and spatial data visualization in supplying custom products and on-demand services. The existent resources can be described as the fundamental datasets with a certain scale, various generalization operators, and the symbol style library in mapping system. Hereby, the formalization definition of user requirements is given. The requirement extraction module is designed to link user requirements and information resources. Users interact with the interfaces to import their requirements, the various parameter items of requirement formalization description can be obtained, and the extraction result is the basis of producing custom products. The requirement extraction module makes it easy for supplying user custom products and on-demand services.