This study first identified the positioning of the case site, its treatment in park planning of Daisetsuzan National Park, the topography of Sounkyo, Daisetsuzan National Park, and incident circumstances of rockfalls there. Next, drawing on references regarding responsibility and acceptance for rockfalls and rockslides in natural parks, prediction and countermeasures for rockfall risk in Yosemite National Park, and case studies of countermeasures to rockfalls and rockslides in other two national parks in Japan, this study explored key issues on how to accept risks and mitigate damage within acceptable limits by visitor risk management for addressing rockfalls and rockslides observed in Kobako, Sounkyo, Daisetsuzan National Park. Key issues for determining whether to permit entry and use include legal frameworks, judicial precedents, social norms, administrative treatment and history, natural and social science findings. If access is permitted, key issues include setting acceptable limits based on scientific knowledge for risk management, implementing proactive measures to mitigate damage within those limits, and defining the scope and constraints of post-incident measures by continuous rockfalls.
Akihiro KOBAYASHI (Thu,) studied this question.