Urban information model for city planning

City planning is a complex task and therefore needs to consider the interplay between multi-aspects of a city, for example, transport, pollution, and crime. A city model is important to representing urban issues in a clear manner to the relative stakeholders. Although some city models have been used in the planning process, they are often based on narrow data sets. When sustainability and the quality of urban life generally is considered a more holistic analysis of city issues during the planning process is needed. It calls for city models to be based on integrated data sets. The paper describes the concept and challenges of nD urban information model. The research work on how to develop an nD urban information model to accommodate data sets relevant to different aspects of city planning is presented.