Emergency counterplan of urban systems to volcanic disaster of Mt. Unzen Part I lifeline

Mt. Unzen erupted last November 17th after 198 years of silence. Residents of Shimabara city were forced to evacuate their homes due to debris flow of Mizunashi River, which is located below Mt. Fugen. Pyroclastic flow-a very fast moving mixture of gas and rocks claimed the 43 lives on June 3rd. Disaster prevention officials of urban systems, which are electric power, gas, water supply, electric communication, railway and others recognized the danger of the mountain erupting and considered a counterplan to protect their systems. In this paper, emergency counterplan of lifeline to volcanic disaster of Mt. Unzen are reported and discussed