Japan Geoscience Union Meeting 2025

Presentation information

[J] Poster

M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS12] Mountain Science

Thu. May 29, 2025 5:15 PM - 7:15 PM Poster Hall (Exhibition Hall 7&8, Makuhari Messe)

convener:Akihiko SASAKI(Department of Geography and Environmental Studies, Kokushikan University), Motoshi Nishimura(Interdisciplinary Cluster for Cutting Edge Research, Institute for Mountain Science, Shinshu University), Asaka Konno(Tokoha University)

5:15 PM - 7:15 PM

[MIS12-P05] The impact of increased flow from the typhoon on the gravel bars downstream of Shiogo Dam in the Oi River

*Asaka Konno1 (1.Tokoha University)

Keywords:The Oi river, Dam construction, Gavel bars, Increased flow

The vegetation and gravel bars have not submerged under The Oi River, located in the lower Akaishi Mountains, which features a well-developed braided channel. The water flow significantly decreased after dam construction began in the 19th century, resulting in almost complete water loss in a 22 km stretch downstream of the Shiogo Dam. In the 1980s, a public movement emerged, which had some success, yet minimal water was restored to the area.

In previous research, we examined changes in vegetation cover by analyzing aerial photographs and geomorphic profiles obtained through leveling surveys. Our findings suggest that the vegetation and gravel bars have remained above water since the dam's construction.

In this presentation, we will utilize interval cameras to analyze the increased water flow during a typhoon in 2022 and report on its impacts on the vegetation and gravel bars since the dam construction.