Whitewater Sound Dependence on Discharge and Wave Configuration at an Adjustable Wave Feature

• Published in: Water resources research 2023-08, Vol.59 (8), p.n/a
• Main Authors: Tatum, Taylor A., Anderson, Jacob F., Ronan, Timothy J.
• Format: Article
• Language: English
• Subjects: Acoustics; Discharge; fluvial geomorphology; geophysics; Hazards; Infrasound; Irrigation; Recreational use; Rivers; Seasonal variation; Seasonal variations; Sound; stream acoustics; Stream discharge; White water; White water river recreation
• ISSN: 0043-1397; 1944-7973
• DOI: 10.1029/2023WR034554

Stream acoustics has been proposed as a means of monitoring discharge and wave hazards from outside the stream channel. To better understand the dependence of sound on discharge and wave characteristics, this study analyzes discharge and infrasound data from an artificial wave feature which is adjusted to accommodate daily changes in recreational use and seasonal changes in irrigation demand. Monitorable sound is only observed when discharge exceeds ∼35 m3/s, and even above that threshold the sound‐discharge relationship is non‐linear and inconsistent. When sound is observed, it shows consistent dependence on wave type within a given year, but the direction of this dependence varies among the 3 years studied (2016, 2021, and 2022). These findings support previous research that establishes discharge and stream morphology as relevant controls on stream acoustics and highlights the complex, combined effects of these variables. Plain Language Summary Previous research has explored the potential of using sound to measure stream discharge and evaluate stream hazards. Discharge and wave types were examined at an artificial wave feature that changes formation to adapt to daily changes in recreation and seasonal changes in irrigation. Through this study, we found that monitorable sound is only observed over a certain threshold and that the formation of the wave affects sound consistently during the year but changes between years, potentially due to outside effects on the overall stream. Future work should aim to better understand wave formation and specific wave traits that contribute to certain patterns of sound. Overall, this study supports the findings of previous research and applies them further by investigating the combined, complex effects of stream traits on sound. Key Points For the first time, we examine combined effects of discharge and wave morphology on infrasound Monitorable infrasound is only produced above discharge rates exceeding ∼35 m3/s Wave morphology has potential to create powerful or insignificant infrasound, but interannual geomorphic changes may also be significant