[G-02] Comprehensive disaster prevention education

[G02-01] How to convey "Don't depend on hazard maps completely"

★Invited Papers

*Hiroshi Une^1,2 (1.retired: Geospatial Information Authority of Japan , 2.Ochanomizu University; Research Collaborator)

Keywords:hazard map, landform classification map, high school geofraphy

A hazard map is defined as a representation of various types of distribution information related to the risk of natural disasters on paper, electronic screens, etc. for the purpose of mitigating disasters (Suzuki et al. 2015). Of these, mainly municipalities superimpose information necessary for evacuation based on disaster-related information and distribute it to residents under the name of "disaster prevention map" is called a “hazard map in a narrow sense” here. The preparation of hazard maps in a narrow sense has progressed due to the obligations of the Flood Control Law, etc., and the national and local governments often ask residents to check the hazard map and take evacuation action based on it, because the inundation area of recent floods has generally matched the assumptions of such hazard maps. This in itself is extremely important, but when using hazard maps in a narrow sense, it is necessary to keep in mind that they are based on the results of computations based on certain assumptions. In other words, as the phrase "Don't depend on hazard maps completely" indicates, we should understand the assumptions that form the basis of hazard maps in a narrow sense, and what kind of assumptions are being made. It is necessary to consider countermeasures while keeping in mind that phenomena that differ from assumptions may occur. The tsunami caused by the 2011 Tohoku Earthquake greatly exceeded the expected inundation area and depth, and in Miyagi and Fukushima Prefectures in particular, an area several times larger than expected was inundated. It was pointed out that "the hazard map based on the previous assumptions may have been a reassuring factor, and the tsunami that surpassed it may have expanded the damage." In order to understand the risk of disasters that do not depend on assumptions, it is important to understand how the land under our feet have been formed and what kind of natural processes will work in the future. A landform classification map tells us this. The original landform of the current land is obscured due to river improvement and artificial alteration of the land, but once a disaster occurs, the land tries to return to the workings of nature. Although it is difficult to directly read land conditions and disaster risks from landform classification maps, for example, using the GSI Map of the Geospatial Information Authority of Japan or the hazard map portal site of the Ministry of Land, Infrastructure, Transport and Tourism, you can display the history of the land and the risk of natural disasters at the location with a single click. In high school geography, which started as a compulsory subject from the 2022 under the new Course of Study, "maps/GIS" and "disaster reduction" are to be taught with emphasis. Taking advantage of this opportunity, I would like to propose disaster reduction education that takes us one step further than the hazard map.