Sound dependence on discharge and configuration at an adjustable hydraulic jump.

In this study, we use acoustic data to determine how sound characteristics depend on discharge and hydraulic jump configuration at a dam that creates an adjustable artificial hydraulic jump. Past research at this site establishes a relationship between hydraulic jump strength and associated seismoacoustic fields as well as a distinct threshold of hydraulic jump strength that alters this sound. However, specifics on how discharge and hydraulic jump strength jointly affect whitewater sounds remain unknown. To answer this, we analyze infrasound and audible sound recordings from spring 2016 and 2021 at this controlled whitewater recreation feature that frequently adjusts according to discharge, recreational use (hydraulic jump strength), and irrigation needs. Our findings indicate that changes in sound characteristics sometimes follow scheduled adjustments in hydraulic jump strength, but at other times correspond to other changes in dam configuration besides day-to-day jump strength adjustments. These findings support a dependence of the acoustic field on hydraulic jump configurations. However, they also indicate a more complex relationship between dam configuration, discharge, and sound than simply depending on hydraulic jump strength. In conclusion, discharge alone cannot explain whitewater sound recordings, and the morphological factors that affect whitewater sounds can be more complicated than past research suggests.