Hazards 2002, October 3-6, Antalya / TURKEY

A GIS-BASED SIMULATION MODEL OF INFORMATION TRANSMISSION
FOR TSUNAMI EVACUATION AND REFUGEE REACTIONS
Toshitaka Katada
Associate Professor, Department of Civil Engineering, Gunma University
1-5-1 Tenjin-cho, Kiryu, Gunma, 376-8515 JAPAN
Phone: +81-277-30-1651 Fax:+81-277-30-1601
katada@ce.gunma-u.ac.jp
Noriyuki Kuwasawa
Researcher, Nippon Koei CO., LTD.
Harry Yeh
Professor, University of Washington
Shun-ichi Koshimura
Researcher, Disaster Reduction and Human Renovation Institution
Akichika Ishibashi
Senior Researcher, Nippon Koei CO., LTD.

Unlike other types of natural hazards, a tsunami can affect very broad regions since it canpropagate more than several thousand kilometers across the oceans without losing its energy.
Its genesis is unpredictable and unobservable because it occurs under the sea. It is a rare
event, and the behaviors and characteristics are quite distinct from other coastal hazards (suchas storm waves). Unfortunately, the normally quiescent coastal areas that are struck bytsunamis are also preferred sites for human habitation. Because of these unique factors,mitigation measures for tsunamis must rely on the first-order defense, i.e. evacuation ofpeople from tsunami inundation areas to save human life. From this view point, tsunami
warning and its information transmission to the individuals are critical.
We have developed a GIS based tool to simulate information transmission from theauthorities to the general publics. The simulation system was originally developed for theother type of natural hazard, i.e. flood. None the less, the lead time for tsunami evacuation ismuch shorter than the case of flood. For distant tsunami, the lead time can be as long as 24hours (e.g. the 1960 Chilean Tsunami in Japan). For a near-source tsunami, it can be a few
minutes (e.g. the 1993 Okushiri Tsunami) to about an hour (the 1992 Nicaragua Tsunami).
The short lead time for tsunami makes evacuation challenging and information transmission
to the general publics must be effective and efficient. Our simulation system is useful to make
improvement in tsunami evacuation strategies by applying it as a scenario simulator. It canalso used effectively to diagnose the existing tsunami emergency evacuation plans.
Our simulation system is based on the Biased Network Model, that is often used for thehuman network analysis in the field of mathematical sociology. The model includes a varietyof transmission means including loudspeakers both fixed and mobile attached to police or firevehicles and helicopters, individual communication network via telephone lines and oralcommunications, as well as mass media such as radio and television broadcasting (Fig.1). We

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Hazards 2002, October 3-6, Antalya / TURKEY

integrate such communication means in our GIS framework so that the informationtransmission patterns can be conveniently visualized both quantitatively and dynamically(Fig.2). The visualization is critical for the users to grasp the local and global informationtransmission patterns for the rational evaluation. After the simulation, all the relevant
functional parameters are computed and presented as the time-series data for furtherevaluation. Our simulation system is still in a developing stage and needs to evolve further,for example, human psychology as well as cultural elements can be incorporated in the future
model. None the less, the framework for the useful evaluation tool is establish for the firstorder mitigation measures against potential tsunami attacks.

Occurrence or
Appearance ofDisasters ››The AuthoritiesEx.
Ex. Government
Government
Announcement

MediaMedia
Fixed Loudspeaker
Patrol Car
Fire Engine
TV and Radio…etc

Fig.1 The Basic Structure of Simulation

Fig.2 A typical simulation on GIS

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CitizenCitizenOral and Telephone
Communication