Abstract
The volcanic disaster of Mt. Fugen in Unzen erupted November 17th 1990 are prolonged and enlarged more than four years. Disaster prevention officials of lifeline systems, recognized the danger of the mountain eruption and considered a counterplan to protect their facilities. They also considered emergency and permanent restoration plans after debris flows and pyroclastic flows attacked their facilities.
In this paper, emergency counter plan, damage and both temporary and permanent restoration plans of lifeline systems to volcanic disaster of Mt. Unzen are reported and discussed. Problems which now have to be solved as well as some lessons to be learned are also explained.
