日本地球惑星科学連合2019年大会

講演情報

[E] ポスター発表

セッション記号 M (領域外・複数領域) » M-TT 計測技術・研究手法

[M-TT47] 人新世における高精細地形・地球物理データの活用

2019年5月27日(月) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:早川 裕弌(北海道大学地球環境科学研究院)、楠本 成寿(富山大学大学院理工学研究部(都市デザイン学))、Gomez Christopher(神戸大学 海事科学部 海域火山リスク科学研究室)

[MTT47-P01] High-definition topography monitoring after riverbed cultivation in the Echi River, central Japan

*小倉 拓郎1,2淺野 悟史3水野 敏明3東 善広3北井 剛4早川 裕弌5,6飯塚 浩太郎6 (1.東京大学大学院新領域創成科学研究科、2.北海道大学大学院環境科学院、3.滋賀県琵琶湖環境科学研究センター、4.滋賀県立琵琶湖博物館、5.北海道大学地球環境研究院、6.東京大学空間情報科学研究センター)

キーワード:高精細地形情報、河床耕耘、UAV、SfM多視点ステレオ写真測量、愛知川

Natural processes of erosion and deposition on riverbeds are generally limited in Japan due to large-scale public constructions including dams and banks. As a result of the construction of dams, sediment transport may dramatically decrease in the downstream area are, and the river ecosystem can also be affected. To make sediment move more vigorously, we cultivated the armored gravel riverbed with heavy machinery. We then explore the effects of riverbed cultivating by monitoring the topographic changes with high-frequency and high-definition measurements (HF-HD measurements), whereas conventional measurement technologies do not compensate spatial resolution and temporal resolution to capture the topographic change. Using UAS (Unmanned Aerial Vehicle) and SfM-MVS (Structure-from-Motion – Multi-view Stereo) photogrammetry, we found the transportation of the fixed gravels were occurring after cultivating the riverbed in 2017. The temporal and spatial resolutions of the HF-HD topographic data was approximately 2 months and 10 cm, respectively. In July 2018, water flow at 130 m3/s was discharged from the upstream dam, and we confirmed that a part of the gravels in the cultivated area was eroded and replaced with new sediments (Fig. 1). These observations indicate that riverbed monitoring using UAV and SfM - MVS can be a practical tool for proper management of riverbeds. Applying this result, we will further clarify the relationships between the water quantity discharged from the dam and the riverbed topographic changes.