Conceptualization of 'Managed Retreat' and Re-naturalization through Buyout Project for Disaster Risk Reduction and Recovery

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K22440
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0304:Architecture, building engineering, and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: Otsuyama Kensuke 東京大学, 先端科学技術研究センター, 特任講師 (50881992)
• Project Period (FY): 2020-09-11 – 2023-03-31
• Keywords: 気候変動適応策 / バイアウト / 撤退 / 宅地の再自然化 / 事前防災投資

Outline of Final Research Achievements

This study examines methods for disaster mitigation and recovery projects through case studies of buyout and re-naturalization of residential land and buildings that contribute to reducing damage from natural disasters. Based on the past 30-year data of FEMA in the United States, the author quantitatively showed the transition of the invested budget and the transition of the high-floor subsidy project budget. As an important conclusion, DRR investment in the U.S has clearly shifted its institutional focus from post-disaster recovery budgets to pre-disaster mitigation. In addition, through interview surveys of non-participants in the buyout project, it was suggested that the intention to settle in the area was not based solely on the degree of reccurrence of damage and cost, and that disaster risk alone was not the only variable that determined the choice of migration or settlement.

Free Research Field

都市計画・防災計画

Academic Significance and Societal Importance of the Research Achievements

研究機関全体の成果として，査読付き論文の発表１編，学会発表４編と「研究活動スタート支援」としては十分な成果が得られた．また同研究期間の後半には科研費「若手研究」に採択され，本研究の持続的発展もみられた．同様に本研究活動を通じて得られた国内外のネットワークによって国際共同研究も開始されたことから，研究スタートとしての意義を果たしたと考えられる．
また社会的意義として，災害復興における「創造的」または「建設的」復興だけではなく、再自然化させる取り組みがあることを紹介し，そのメリットと課題も一定程度示すことが出来たと思われる．