Towards a typology of spatial relations and properties for urban applications

Relations that occur between features located in space –like the fact that a street is surrounded by very high buildings, that an airport is close to a city- as well as properties of features that have a spatial aspect in them –like the shape or a comparative property with neighbouring features- play an important role for many urban applications. Hence, considering the objective of explaining to potential users of city data what useful information they can derive from these data and how, a possible way to address this objective lies in the usage of a pivot model composed of relevant spatial properties and relations, connected to information meaningful to the user and connected to the possible computation of them on available data. This paper firstly sets the ground for a typology of such relevant relations and properties that are shared by different applications and that can be derived/approximated from existing data. It then proposes a model to describe these properties and relations and connect them to their possible computation based on data (2D or 3D). An important aspect of this model is to distinguish between a conceptual layer where relations occur between “real world” features and an implementation layer where they are calculated based on database features and geometries.