Distributed Disaster Information System over Japan Gigabit Network

In this paper, a robust and large scale residentoriented safety information system on the occurrence of the various disasters constructed over a nationwide high-speed network is introduced. The resident evacuated can registered his/her safety information in the local safety information servers in the evacuation area whether he/she can safely evaluated or not using mobile PCs or terminals at the evacuation area or mobile terminals on the way of evacuation. All of the local information servers are connected each other by wireless network and the safety information can be sent an upper-layer database in the district area and finally integrated into a district safety information in that region. In our system some of the damaged local servers due to the disaster can be detected and recovered manually by the upper-layer database server. On the other hand, the upper-layer database servers are backed up by mirror servers located to mutually different locations with long distance to isolate the influence to the same disaster when the some of them were destroyed or disordered. Thus, by introducing two levels of redundancy and backup functions, more large scale and robust safety information database system can be realized.