Among the 132 municipalities near 47 volcanoes being monitored for eruptions, 48 - or only 37 per cent - of relevant local governments have compiled evacuation plans, according to a Yomiuri Shimbun survey.
Of the 47 volcanoes the Japan Meteorological Agency is constantly keeping an eye on, only 22 of them feature shelters or other evacuation facilities.
Sunday marked the first anniversary of an eruption of Mt. Ontake, which straddles the border of Nagano and Gifu prefectures. The eruption of the 3,067-meter-high mountain was the worst volcanic disaster in Japan since the end of World War II.
The survey results shed light on the reality that measures to cope with volcanic disasters have not sufficiently progressed.
The Yomiuri survey covered local governments that are required to stay alert in case of a volcanic eruption.
Following a revision in July of a law stipulating special measures to deal with active volcanoes, many local governments subject to it will likely be required to compile detailed evacuation plans.
The survey was conducted from Aug. 24 to Sept. 25 via question sheets and telephone calls. A total of 131 municipal governments responded. Of them, only 48, or 37 per cent, said they have already compiled evacuation plans.
Of them, 33 said they have evacuation plans that include measures for tourists and climbers. Forty-six municipal governments, or 35 per cent, said they are compiling their evacuation plans.
Thirty-seven municipal governments, or 28 per cent, said they have not yet started to compile evacuation plans, including the government of Ogasawara village, Tokyo, which is at risk of Iwoto, a volcanic island where no ordinary residents live.
Regarding the reasons for not yet compiling evacuation plans, six of the municipal governments said they put priority on evacuation plans for other disasters, such as earthquakes and tsunami.
Five municipal governments said there are no signs of nearby volcanoes becoming more active.
Aside from municipal governments, the survey also asked prefectural governments whether they have built concrete shelters on volcanoes for people to evacuate to during an eruption.
Among the 47 volcanoes, 22 feature at least one such evacuation facility, although it is assumed the capacities of these shelters are inadequate in many cases.
Municipal governments near four volcanoes oblige climbers to submit prior reports of their trekking plans. The reports are deemed useful for guiding the climbers, and also searching for and rescuing them if there is an emergency.
According to the Gifu prefectural government, following its establishment in April of a rule that obliges Mt. Ontake climbers to submit prior reports, the number of reports submitted rose by about 6 per cent from a year earlier.
At 27 of the volcanoes, climbers are asked to submit prior reports on a voluntary basis.
Hirotada Hirose, a professor emeritus of Tokyo Woman's Christian University and an expert in disaster risk studies, said: "Near volcanoes, many local governments suffer from depopulation and fiscal hardship. Thus, assistance from the central government is important."