The Vulnerability of a City - Diagnosis from a Bird's Eye View

When the tsunami in the Indian Ocean on 26 December 2004 hit the city of Banda Aceh on the island of Sumatra, Indonesia, neither the city administration nor its inhabitants, nor national or international organisations were prepared. Approximately 60.000 of the 260.000 inhabitants died, leaving other 30.000 homeless and causing an enormous impact on the local economy. In the aftermath of this event tsunami early warning system were developed and are operated today (e. g. the German Indonesian Tsunami Early Warning System – GITEWS (Lauterjung, 2005)). However, the problem of earthquake or tsunami prediction in a deterministic sense has not been solved yet (Zschau et al, 2002). Thus, an end-to-end tsunami early warning system includes not only the tsunami warning, but also the assessment of vulnerability, perception studies, evacuation modeling, eventually leading to technical requirements for monitoring stations and recommendations for adaptation and mitigation strategies (Taubenböck et al., 2009a). In this study we address several specific questions on the capabilities of one discipline – remote sensing – for diagnosing the multi-faceted and complex vulnerability of a city: • Which remotely sensed data sets are appropriate analyzing vulnerability in highly complex urban landscapes? • What capabilities and limitations does urban remote sensing have regarding mapping, analysis and assessment of risks and vulnerability? • How can interdisciplinary approaches extend the applicability of earth observation