Kurzfassung
Was geschieht, wenn Hochwasser mit einem bestimmten Pegel durch die Stadt fließt? Wie viele Einwohner müssen evakuiert werden? Wie viele Kindergärten, Schulen, Krankenhäuser, Wohn- und andere öffentliche Gebäude sind betroffen? Wie viele Leute befinden sich innerhalb von Gebäuden? Wo sind mögliche gefährdete Gebiete, wenn das Hochwasser über die Ufer tritt? Wie groß sind diese Bereiche? Wo ist der optimale Weg für Fahrzeuge der Feuerwehr, wenn Verkehrswege überflutet sind? Wie hoch sind die abschätzbaren Schäden, die in der Landwirtschaft bzw. in Industrie-, Wohn- oder Bürogebieten entstehen könnten? Um alle diese Fragen beantworten zu können, wurde über einen Zeitraum von 3 Jahren von der Technischen Universität Graz und der Stadt Graz gemeinsam ein hybrides System entwickelt, das aus einem hydrodynamischen System und einem Geoinformationssystem (GIS) kombiniert ist. Die charakteristischen Eigenschaften des System-designs werden in der Folge beschrieben. Im Besonderen wird dabei auf das Datenbankdesign, die Überführung der Ergebnisse des hydrodynamischen Systems in die Datenbank, die Datenfusion und die Analyse der Teilbereiche eingegangen.

Abstract
What happens if deluge of level x were passing through the city? How many inhabitants have to be evacuated? How many kindergartens, schools, hospitals, residential and others public buildings were involved? How many people were inside the buildings? If the flood burst the river banks, where were most possible dangerous locations? How big was each of the gaps? If the traffic system were under water, say from A to B, where was the optimal route for fire bridge vehicles? After the flood, what the tangible damages either in agriculture, industrial or residential/commercial areas might look like? To answer all these practical questions, one hybrid system combined of hydrodynamic system and GIS was developed jointly by Graz University of Technology and City of Graz for about three years. The characteristic features of the system design are described. Especially, database design, adoption of the results from hydrodynamic system into database, data fusion and analysis subsystems are delineated in detail. Most distinctive features of the system are following: a) Results of different hydrodynamic systems can be adopted into the system; b) The requirement of basic data, either from hydrology or geoinformation, is scalable. If the minimal requisite of the data source is available, the system is operational, even the more data sources are the more extensive analysis resulted; c) Comparing to other flood hazard maps, the system can be used as tools before, during and after the flood disaster happening. It delivers not only graphical overview of the deluge scope, but also suggests the rescuers with numerical analyzed results interactively. For decision maker, water related authorities, fire brigades or other disaster rescuers, and insurance companies the system gives either generated damage scopes or detailed numerical information; d) The developing platform is based on one of most up-to-date GIS system. Two forms of the system may be implied, as plugin solution of ArcGIS 9.x© or as stand along solution based on ArcEngine9.x© library. Since 2005 this system is tested and implicated along the river Mur in Graz city area. The application by the city fire brigade and annual adjusted results are presented.