Green infrastructure functions of traditional river structures in Japan

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K12842
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Environmental and ecological symbiosis
• Research Institution: Kyushu University
• Principal Investigator: Hayashi Hironori 九州大学, 工学研究院, 准教授 (00599649)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 河川構造物 / 伝統工法 / グリーンインフラ / 堰 / 川づくり / 災害復旧 / 環境再生 / 河川環境

Outline of Final Research Achievements

In this study, the function of the traditional river structure as a green infrastructure was evaluated from both sides of environment and flood control. The outline of the obtained results is as follows.
The traditional river structure functions as a habitat for aquatic organisms equivalent to natural rivers, and has an environmental function superior to that of a concrete type river structure. Field observations and hydraulic experiments during floods have quantitatively shown the water flow and energy depletion function of traditional river structures during floods. The hydraulic experiments showed that traditional river structures have the effect of reducing flow velocity when overflowing compared to concrete structures. The results of this research were reflected in the disaster restoration project, and the stone structures in the Notori River were restored in collaboration with river managers and residents.

Free Research Field

河川環境

Academic Significance and Societal Importance of the Research Achievements

本研究の特色は伝統的河川構造物をグリーンインフラという新しい概念で捉え、環境機能と防災機能の両側面から評価を行う点である。これまで知られていなかった伝統的河川構造物の環境機能と治水機能を定量的に明らかにするという学術的な意義を有する。その成果は、伝統的河川構造物の価値をわかりやすく示し、河川構造物の整備手法をグレーインフラ的手法から伝統的技術を活用したグリーンインフラ的手法へ転換させることに寄与するという社会的意義を有する。さらに歴史文化的価値と併せることで、伝統的河川構造物の文化財指定や文化的景観指定などの可能性を高めるものと推測される。そのため地域の価値の向上させる地方創生的意義を有する。