Abstract: Serious disasters have been annually occurring in Japan. For example, in the Great East Japan Earthquake that occurred on March 11, 2011, communication infrastructure was seriously damaged over a wide area. From such a situation, more resilient network infrastructure that does not stop under challenged communication environment is required. In this paper, we propose a Disaster Information System that can flexibly deal with failures of the server group and respond to rapid load change. We construct the disaster information system based on the cloud computing technology. In addition, we develop a dynamic allocation of server resources in accordance with the load change on the system so that it makes possible to take full advantage of the resources in the disaster areas. A significant role of good user interface design is to enhance user experience. Keywords and icons are heavily used in mobile applications because of the limited screen size and small keypad interface. In creating a mobile based crowd sourcing application to motivate citizens to report disaster events and experiences, use of keywords and icons should be intuitive, have high recall and make reporting accurate. This paper discusses the user validation results of user interface design through user experience measured by intuitiveness, recall, and accuracy. Also, by introducing a mobile cloud and DTN protocol, our system can realize rapidly sharing disaster information even though the communication breakdown area occurred.

Keywords: Disaster Information System, Load Change, Disaster Information.