INTEROPERABILITY IN 3D CITY MODELS DEVELOPED FOR EARTHQUAKE VULNERABILITY VISUALIZATION
S. Kemec, H.S. Duzgun
METU, Geodetic and Geographic Information Technologies,
In the urban disaster management domain, in order to generate decisions from heterogeneous information types, decision makers must be able to identify relations between information types. The perception of the decision makers and the visualization of the abstract information are tightly interrelated, and must be considered and understood together.
3D urban visualization methods currently don’t reflect an integrated manner for the data visualization or support a unified interface. A disaster Spatial Decision Support System (SDSS) which is generated by the integration of the GIS, visualization and simulation properties; provides important information for different aspects of disaster management. And these systems should be required to link with environmental planning, development, and sustainable development applications. They should use interoperable algorithms, methods and data, to reduce duplication of efforts and to serve for effective disaster management.
Interoperability is the key fact at this point and syntactic, semantic interoperability should be achieved for a sustainable management. Syntactic interoperability is achieved with XML based language of CityGML. Another must for an interoperable GIS is semantic interoperability. Semantic, geometrical and topological aspects of 3D city models are covered with class definitions of CityGML. All City basic components; buildings, other man-made artifacts, vegetation objects, water bodies, and transportation facilities included to the class taxonomies.
In this study, CityGML which is designed by the OGC to serve as the standard exchange format for spatial data infrastructures is used for a pilot 3D urban model. The pilot model area is the Cumhuriye neighborhood of Eskisehir, Turkey. 1/25.000 scale digital elevation contour maps, Stereo Ikonos Satellite images, building facade images and 2D vector layers of the study area are the data sources of the model. The data are converted to be used in interoperable environment, which is CityGML, then a series of raster and vector GIS operations are performed for the development of virtual 3D city model. The computed earthquake vulnerabilities of each building are visualized in order to create better cognition of existing earthquake risk by the decision makers.