Geographic information is a prerequisite for good governance. There are various urban geographic information system projects that have been produced by local governments all over the world. However, there are technical difficulties, a lack of spatial data standards and specific policies governing geographic information system projects. The result of the current situation is that the process of data collection is sometimes inefficient and the quality of the data may be inadequate. Furthermore, there are problems with managing projects and sharing data. The key to resolving these problems is to develop a harmonised geographic information model for the urban governance of Turkey. The model should fulfill the application-driven geographic data needs of local governments and support decision-making processes at regional and national levels. The domain model is an object-relational model and the starting point for creating sector models. The generic conceptual model components were defined to harmonise geographic data and to produce data specifications. In order to enable semantic interoperability unified modelling language has produced the application schemas for data themes such as administrative unit, address, cadastre/ building, hydrographic, topography, geodesy, transportation, and land cover/ use. The model has been tested and revised with local applications such as economic and demographic spatial analysis cases.