Improvement of the float measurement method using quasi-3d flood flow analysis

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K14730
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Hydraulic engineering
• Research Institution: Okayama University
• Principal Investigator: Akoh Ryosuke 岡山大学, 環境生命科学研究科, 准教授 (90599333)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 浮子観測 / 準三次元解析 / DIEX法

Outline of Final Research Achievements

In this study, we construct a modified calculation method of river flow rate by using a numerical float model based on quasi-three-dimensional flood flow analysis and DIEX method to estimate velocity distribution in cross section using observed velocity data. From channel experiments and numerical experiments, the basic flowchart of the proposed method was examined and the correction effect was investigated. As a result, about 15% was achieved by the proposed method. Furthermore, as a result of comparing and examining the flood flow analysis and the estimated discharge by the proposed method for the past floods at the Nakahara Bridge Observatory in Asahi River, an improvement of up to about 7% was achieved. The proposed method can be used additionally to the existing method, so it is useful in practical for river management.

Free Research Field

水工学

Academic Significance and Societal Importance of the Research Achievements

我が国の河川における高水流量観測には浮子法が用いられてきた．近年，ADCP（超音波），電波式（マイクロ波），画像解析等の高度な観測手法の開発が進められ，実河川での実用化が見られるようになっているが，これらの観測手法が完全に浮子法の代替として用いられるには，安全性，迅速性，確実性，そしてコストの面でまだ多くの課題が残されている．本提案手法は，既往の浮子法を観測手法自体は変更させることなく，得られた観測値を用いて推定精度を向上させるものであり，実務への適用が比較的低コストな点，過去洪水の浮子観測データの利用可能な点は，治水対策の高度化に有用な特徴であり，社会的な意義があると考えられる．