1:45 PM - 2:00 PM
[HDS08-01] Questionary Survey on Evacuation Behavior Based on Climber Participation Evacuation Drill assuming Eruption of Mt. Ontakesan, central Japan
Keywords:Evacuation drill, Volcano, Climber, Evacuation behavior, Questionnaire survey, Ontakesan
Study aimThe victims of the 2014 eruption of Mt. Ontake were climbers within a radius of 1 km from the crater. Local governments, where the volcano is located, have been working to strengthen disaster prevention capabilities for climbers. Due to progress in physical measures to protect humans for Mt. Ontake, Kiso Town conducted the first evacuation drill to climbers in order to publicize the shelter this year. In conjunction with this evacuation drill, we conducted a questionnaire survey to the participants to clarify the behavior that climbers take during the evacuation drill.Evacuation drill methodThe evacuation drill was conducted in the Kurosawaguchi route on the assumption that a phreatic eruption suddenly occurred from about 500m southwest of Kengamine. At 12:10 pm on September 17, 2022, according to the manual, a siren was sounded on the disaster prevention administrative radio, informing that the eruption was occurred and calling climbers to evacuate.
First of all, we urged the climbers to prevent accidents, and then we gave evacuation training instructions describing five actions that the participants should take at mountain entrances. The instructions were: 1 protect the head and back, 2 find an evacuation facility, 3 evacuate on foot if there is a shelter or mountain hut, 4 stay where there is no evacuation facility, and 5 confirm your location and think about what you can do by yourself if eruption is occurred.resultThe number of respondents to the questionnaire was 347, about 54.2% of the about 640 people who distributed the instructions. Respondents were mostly of the working generation (22-59 years old), accounting for 82.1% of the total. 17.0% were over 60 years old.
The number of responders who knew their own location was 90.8%. Those who had low recognition for location were those who visited Mt. Ontake for the first time and the elderly. The locations of climbers were 20.2% and 19.3% on the 8th to 9th and on the 9th to 10th points of the mountain trail, respectively, and 16.1% on Kengamine peak, and 13.8% and 10.7% on and around mountain huts located at the 8th and 9th points, respectively.
Climbers who said they found a place to hide when the siren sounded tended to be related to their number of climbs and their location. 62.2% of those who have climbed the mountain six or more times found a place to hide, while only 55.2% of those who have climbed two or three times and 40.3% of those who had never done so. Inexperienced climbers tended not to find evacuation sites. By area, 94.6% and 50.0-78.6% of people found evacuation sites in areas with shelters and mountain huts, respectively, while only 18.6-25.4% of people found evacuation sites on the 8th to 10th stations. 60.0% to 68.7% of those who did not. On the mountain trail, it shows that there are few escape places at the time of eruption.
The audibility of the siren sound tended to be related to the position of the equipment and the position of the climber. The morning of the training was fine, but it turned to rain during the training, resulting in thick fog and strong winds. In Kengamine, where the disaster prevention administrative radio system was installed, 91.1% of the people could hear the siren, and all the people could hear the siren, including the 8.9% who answered that they could hear it faintly. Also, on the mountain trail 9th to 10th points and around the 9th point where the mountain huts are located, the percentage of people who could hear was lower than that of Kengamine. 54.3% could be heard on the area between the 8th to 9th points where the disaster prevention administrative radio was installed, which was higher than at the 9th point on the trail. Our survey confirmed that no sirens could be heard in the four huts.
Actual evacuation behavior was 76% in Kengamine evacuated to shelters, and 12.5% hid behind buildings. 29.9% of people hid behind rocks, 14.9% did not know what to do, 13.4% did nothing, and 13.4% started to descend.
First of all, we urged the climbers to prevent accidents, and then we gave evacuation training instructions describing five actions that the participants should take at mountain entrances. The instructions were: 1 protect the head and back, 2 find an evacuation facility, 3 evacuate on foot if there is a shelter or mountain hut, 4 stay where there is no evacuation facility, and 5 confirm your location and think about what you can do by yourself if eruption is occurred.resultThe number of respondents to the questionnaire was 347, about 54.2% of the about 640 people who distributed the instructions. Respondents were mostly of the working generation (22-59 years old), accounting for 82.1% of the total. 17.0% were over 60 years old.
The number of responders who knew their own location was 90.8%. Those who had low recognition for location were those who visited Mt. Ontake for the first time and the elderly. The locations of climbers were 20.2% and 19.3% on the 8th to 9th and on the 9th to 10th points of the mountain trail, respectively, and 16.1% on Kengamine peak, and 13.8% and 10.7% on and around mountain huts located at the 8th and 9th points, respectively.
Climbers who said they found a place to hide when the siren sounded tended to be related to their number of climbs and their location. 62.2% of those who have climbed the mountain six or more times found a place to hide, while only 55.2% of those who have climbed two or three times and 40.3% of those who had never done so. Inexperienced climbers tended not to find evacuation sites. By area, 94.6% and 50.0-78.6% of people found evacuation sites in areas with shelters and mountain huts, respectively, while only 18.6-25.4% of people found evacuation sites on the 8th to 10th stations. 60.0% to 68.7% of those who did not. On the mountain trail, it shows that there are few escape places at the time of eruption.
The audibility of the siren sound tended to be related to the position of the equipment and the position of the climber. The morning of the training was fine, but it turned to rain during the training, resulting in thick fog and strong winds. In Kengamine, where the disaster prevention administrative radio system was installed, 91.1% of the people could hear the siren, and all the people could hear the siren, including the 8.9% who answered that they could hear it faintly. Also, on the mountain trail 9th to 10th points and around the 9th point where the mountain huts are located, the percentage of people who could hear was lower than that of Kengamine. 54.3% could be heard on the area between the 8th to 9th points where the disaster prevention administrative radio was installed, which was higher than at the 9th point on the trail. Our survey confirmed that no sirens could be heard in the four huts.
Actual evacuation behavior was 76% in Kengamine evacuated to shelters, and 12.5% hid behind buildings. 29.9% of people hid behind rocks, 14.9% did not know what to do, 13.4% did nothing, and 13.4% started to descend.