Abstract
The purpose of this study is to measure the effect on infrastructure maintenance of the disaster prevention wharf (call it DPW) for rescue ships, which has been in preparation since the biggest earthquake in the Southern area of Hyogo prefecture. As the method of research, we use graph theory, a blossoming field of mathematics. Our research flow is as follows: Firstly, we select the Tokyo area, particularly Koto ward, as the object of consideration. We construct a graph from the geographic structure, namely, traffic network together with DPW and the waterway network in this area. Then, utilizing new criteria which we invented in this paper, we study the graph structure by looking at various changes of the criteria as we add certain information about the DPW and the waterway network to the construction of a graph. This helps to gain understanding about the effect on the maintenance of the DPW so that the injured can be moved efficiently in a disaster. As a result, we observe the effect of the maintenance of DPWs. Through this study, we can give priorities among several plans for the maintenance of DPWs in view of moving the injured in a disaster.
