11:45 AM - 12:00 PM
[G02-09] Education for awareness about sediment related disasters and trial of providing risk information at an elementary school
Keywords:Landslide, Precipitation, Evacuation
Sediment related disasters such as landslide and debris flow occur locally and unexpectedly. More than 80 % of human damages and losses due to sediment related disasters took place in buildings, implying late evacuation actions during heavy storms. Therefore, it is essential to understand the disaster risks at one’s own place for early evacuation actions. Education of disaster mitigation can contribute to understanding the disasters and their risks, which has been referred in guidelines of disaster mitigations at schools. As available land is generally limited in mountainous areas, public facilities such as schools must be located at areas with danger of sediment related disasters. According to the guidelines above, schools are requested to establish disaster mitigations individually. Real-time risk information of sediment related disasters is useful for schools in mountainous areas. We will present an education program on precipitation and sediment related disasters and real-time risk information based on observation and a simple model at Tochio elementary school, Takayama city, Gifu prefecture.
Because Tochio elementary school is situated adjacent to steep slopes, the site of the school is specified as the high- and very high-risk areas of landslide and/or debris flows (as called as ‘yellow zone’ and ‘red zone’, respectively). A huge debris flow at a torrent close to the school caused casualties and damages in 1979. The adjacent steep slopes and the previous debris flow disaster indicate the risk of the school. Tochio elementary school has been tackled education on mitigation of sediment related disasters in which our lectures, 4 classes per year, have been included. Our education program consists of classes on 1) what are sediment related disasters, 2) precipitation and evacuation actions, 3) ‘Cross-road game’ drill, and 4) what are disasters in winter. To realize amount of precipitation, the relationship between precipitation observed at the school and students’ feeling of precipitation was recorded. The recorded results showed large variations of sensitivity on precipitation among the students, suggesting that the difference between criterions of precipitation for disaster alert and residents’ feeling of precipitation should be recognized and is critical for effective risk information.
To provide real-time risk information for the school, we try to establish a method for evaluating the risk of the adjacent steep slope in real time. Discharge of a spring in the adjacent slope is observed and simulated by a simple function model. The spring discharge is assumed to be correlated to the groundwater level in the slope. Thus, the greater spring discharge can be assumed as the higher risk level of the slope. The input data for the model is only observed precipitation at the school, so that the risk information can be estimated in real time at the school. This information can contribute avoiding human damages at the school.
Because Tochio elementary school is situated adjacent to steep slopes, the site of the school is specified as the high- and very high-risk areas of landslide and/or debris flows (as called as ‘yellow zone’ and ‘red zone’, respectively). A huge debris flow at a torrent close to the school caused casualties and damages in 1979. The adjacent steep slopes and the previous debris flow disaster indicate the risk of the school. Tochio elementary school has been tackled education on mitigation of sediment related disasters in which our lectures, 4 classes per year, have been included. Our education program consists of classes on 1) what are sediment related disasters, 2) precipitation and evacuation actions, 3) ‘Cross-road game’ drill, and 4) what are disasters in winter. To realize amount of precipitation, the relationship between precipitation observed at the school and students’ feeling of precipitation was recorded. The recorded results showed large variations of sensitivity on precipitation among the students, suggesting that the difference between criterions of precipitation for disaster alert and residents’ feeling of precipitation should be recognized and is critical for effective risk information.
To provide real-time risk information for the school, we try to establish a method for evaluating the risk of the adjacent steep slope in real time. Discharge of a spring in the adjacent slope is observed and simulated by a simple function model. The spring discharge is assumed to be correlated to the groundwater level in the slope. Thus, the greater spring discharge can be assumed as the higher risk level of the slope. The input data for the model is only observed precipitation at the school, so that the risk information can be estimated in real time at the school. This information can contribute avoiding human damages at the school.