Efficient discharge monitoring using whitewater sounds

Natural and artificial whitewater features like rapids, waterfalls, spillways, and weirs are important acoustic sources in the infrasound, audible, and ultrasound bands. However, their sounds have received little scientific study despite their utility in monitoring streamflow and their environmental significance as dominant features of the riparian soundscape. In this project, the investigators will build on preliminary work and develop a tool for helping researchers collect important but currently impractical discharge data. This project will create a monitoring method that can enable hydrologists to collect streamflow data more efficiently than is currently possible, removing the constraint of stream-gaging logistics on data collection and permitting studies that are currently impractical. To encourage widespread adoption of the method, they will release a mature, user-friendly sensor/software combination with comprehensive manuals and instructional videos demonstrating fieldwork and data processing for new users. All instrumentation and software produced in this project will be open-source. They will promote hydrological and STEM education at multiple levels by including undergraduate and graduate students in research, instrumentation construction, software development, and K-12 outreach to underserved schools and community organizations. This interdisciplinary project will help train student assistants to work across disciplinary boundaries and teach transferable skills including electronic design and maintenance, field data collection, analysis, and scientific communication.

The investigators will address two research questions: 1) how can acoustic monitoring of whitewater features be used to measure streamflow? 2) how does the spatial distribution of whitewater sounds depend on characteristics of the stream and surroundings? The investigators will address their first question with case studies of many scales, ranging from waterfalls on rivers to riffles on mountain streams. In particular, they will examine the utility of acoustics for recording low-order and intermittent streams, which are under-monitored despite their hydrological, ecological, and policy significance. To answer the second question, they will characterize whitewater soundscapes by collecting snapshot spatial surveys of noise around whitewater features and assessing how discharge, whitewater feature characteristics, vegetation, and topography affect stream noise extent and intensity. This question is relevant to wide-ranging communities including hydrologists (site selection for acoustic gaging), geophysicists (understanding a important and variable source of background noise), ecologists (stream sounds aiding wildlife as navigational beacons, or impairing their ability to hear predators or prey), and urban and recreational planners (background sounds have measurable health effects on humans). This project is co-funded by the Hydrological Sciences Program and the Instrumentation and Facilities Program in the Earth Sciences Division.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.