M. Mueller1, D. Dransch1, M. Wnuk2

1 - GeoForschungsZentrum Potsdam (GFZ), Geoinformation management and -visualisation, Potsdam, Germany

2 - Deutsches Zentrum fuer Luft- und Raumfahrt (DLR) Oberpfaffenhofen, Information Technology, Wessling, Germany


Complex and time critical situations that can be found within the context of early warning require well-designed spatial Graphical User Interfaces (GUIs) which support decision making in a suitable way. They have to present several related spatio-temporal information: the event itself, like flood or tsunami waves; data from different sensors in their spatial distribution and temporal processes; as well as results from vulnerability and risk modelling with their spatial patterns and cost distribution. The spatial GUI of an early warning system needs an efficient visualization of each single information as well as of its combinations. To meet this challenge, the spatial GUI has to be shaped and organised according to the principles of user- and task-orientation as well as cognition.


In a subproject of the German-Indonesian Tsunami Early Warning System (GITEWS) we develop a spatial GUI for complex decision making in a time critical situation. The situation is characterized as follows: an initial event triggers different sensors in a sensor network. If an earthquake event occurs, the seismological sensors alert the guard commander in the control centre. Other sensors follow and deliver data to the control unit - for instance ocean buoys which prove whether a Tsunami wave passed through, or coastal tide gauges which detect water levels. Additionally, Tsunami wave models predict where and when the wave will hit the shore and risk models indicate the vulnerability of an area. The data have different levels of quality which change over time because more precise sensor data arrive at the system. All this information has to be processed and understood by the actor in the control room who has to decide whether and where to deliver a warning to the people at the coast.


The question of our research is how the users of the Tsunami Early Warning System can be supported in fulfilling their tasks in this time-critical situation with the assistance of an appropriate information visualization and interaction mode. A consequent and systematic task analysis with scenario-, workflow- and use case descriptions forms the basis for the requirements of the spatial GUI. To avoid information overload a concept of information aggregation into incidents was developed. A consistent, clear and salient visualization of the spatio-temporal information, as well as suitable interactive windows guide the users through the decision process. This paper will present the concept and the preliminary design results of the spatial GUI as part of the decision support system (DSS) within the GITEWS project.