A 3D data model and topological analyses for emergency response in urban areas

3D geospatial information has always been a challenge due to a variety of data models, resolutions and details, ways of representation (b-reps, voxel, SCG), etc. After 9/11 the interest in 3D models (buildings or undergrounds) for emergency responses is progressively increasing. Such models are mostly available from the design phase (as CAD models). Design CAD models are in most of the cases too detailed for computing, for example evacuation routes. Therefore, this chapter is motivated by the need of a new data model to represent and to analyze 3D geospatial data in emergency management systems for field workers and decision makers. This chapter reviews 3D data models developed for geometric or topological representations of 3D objects and proposes a 3D Data Model for emergency response to represent urban built environments in multi-levels. The proposed data model is a composite model integrating: 1) 3D geometric model to measure and represent 3D spatial objects geometrically only, 2) 3D topological model to represent only the topological relationships among the 3D objects using a network-based model, and 3) 3D city model to visualize the 3D objects in multi-views.