Automated continuous measurement of wash load using fluvial acoustic tomography

2014 Fiscal Year Final Research Report

• Project/Area Number: 24656296
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Hydraulic engineering
• Research Institution: Hiroshima University
• Principal Investigator: KAWANISHI Kiyoshi 広島大学, 工学(系)研究科(研究院), 准教授 (40144878)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 浮遊土砂 / ウォッシュロード / 音響トモグラフィー / 音響インテンシティー

Outline of Final Research Achievements

New method for measuring wash load was proposed. Fluvial acoustic tomography system (FATS) with central frequencies (5, 10 and 30 kHz) was deployed in the Ota River, Gono River and Qiantang River. The FATS enabled us to measure cross sectional averaged flow velocity, streamflow and singa-to-noise ratio (SNR). The cross-sectional average suspended sediment concentration (SSC) was deduced from the SNR. Thus, continuous measurements of the wash load was conducted. Although the viscous absorption of sound due to SSC was around 10 times as large as that from an acoustic theory in shallow rivers (Ota and Gono River), the viscous absorption in Qiantang River was comparable with that from the acoustic theory.

Free Research Field

水工学