Author(s): Kiyosi Kawanisi; Mohamad Basel Al Sawaf; Junya Kagami; Mochammad Meddy Danial; Shinji Okuda
Linked Author(s): Kiyoshi Kawanishi
Keywords: River discharge; Acoustic tomography; High-frequency acquisition; Gravel-bed river; Shallow water flow
Abstract: This study demonstrates a promising acoustic method for measuring streamflow with high temporal resolution for a long period using the fluvial acoustic tomography system (FATS). In contrast to the traditional point/transect measurements of discharge, the FATS enables the depth-and range-averaged flow velocity along the ray path to be measured in a fraction of a second. The field test was conducted in a shallow gravel-bed river (0.8 m deep under low-flow conditions, 115 m wide) during 127 days. The 30 k Hz sound modulated by M-sequence of 9th order was reciprocally transmitted at intervals of 30 s. The streamflow estimates by FATS were well accorded with Rating Curve (RC) and intermittent moving-boat ADCP estimates. Moreover, FATS captured short-wave irregularities in the streamflow time-series unlike with the smooth RC streamflow time-series.
Year: 2017