A New Face-entity Concept for Modeling Urban Morphology

The modeling of a common set of urban land features in a topological structure useful for a range of applications, including routine operations and decision-making, is described in this paper. This collection of non-redundant shareable data is based on an identification of administrative agencies that would use and/or manage these data. Using this information, an object-based conceptual model is developed that employs the face-and-entity concept to account for all basic land units and organizes them into different levels of hierarchy. This structuring is based on physical containment (e.g., building and pavement entities are wholly contained in the block entity, resulting in two levels of faces) and urban management rules (i.e., each face and/or its entities are uniquely managed by a certain authority). The derived conceptual model, including both the meta data and the geometry associated with the face hierarchy, is formalized with EXPRESS, an object-oriented data description language that conforms to universal and regional geographical information system (GIS) terminology and standards. ships and ownership rights. The proposed model also incorporates many of the universally recognized concepts of geoinformation, so that the data structure can be explicitly defined and applied across all urban environments. Being a compact and competitive society, Hong Kong may be an ideal example to illustrate the requirement of a comprehensive data model. The intensive daily activities encourage a carefully designed GIS model for a complex, dynamic, multidimensional configuration of the urban surface. Like many other cities in the world, this “small and big” city has experience in implementing GIS technology in the context of changing objectives, trial and error, and having to tackle both institutional and technical difficulties, in a decade-long development.