When
NEW LOCATION TODAY ONLY!
Harshbarger 110
Seminar Format
Available in-person and via Zoom webinar. Contact the department to subscribe to the email list (zoom link provided in announcement).
Abstract
Before we see a stream, we can hear it. The discharge of that stream can be inferred from measurements of its sound. Sound intensity level is proportional to the energy of the flowing water and is related to discharge by a sound-discharge rating curve. Measurements with a handheld sound level meter, such as a cell phone with a special app, take seconds to acquire, allowing for high-resolution, long-term monitoring of stream discharge, campaign surveys, and ad hoc measurements. Sound measurements correlate well with the standard stream gauge data over the full range of discharges studied, from 0.02 m3/s to 33 m3/s. The following characteristics make the method an attractive alternative to the standard stream gauging: (i) the instrumentation is simple and inexpensive; (ii) field deployment requires no built infrastructure; (iii) the instrument is suitable for rapid or emergency deployment; (iv) the measurements are non-invasive and non-contact, made at a distance from the stream, using a stationary or roving instrument; (v) the acoustic response curve is linear; and (vi) the interfering sound sources are either negligibly small or easily removed.
As a part of the presentation, I would like to invite attendees to create their own sound-discharge rating curve using their cell phones and the Decibel-X app to measure sound intensity. The seminar room's audio equipment will be used to play sound clips recorded in Sabino Creek and independently measured discharges will be provided. The experimental data will be displayed in real time using Google Sheets for everyone to see.
Bio
Marek Zreda is a geologist and hydrologist. He studied geology at the University of Warsaw, Poland, specializing in stratigraphy and exploration. After moving to the US, he undertook studies in hydrology and isotope geochemistry at New Mexico Tech, where he earned an MS degree in 1990 and a PhD degree in 1994. He joined the University of Arizona as a hydrology professor in 1994. Professor Zreda is interested in cosmogenic isotope geochemistry, cosmic-ray hydrology, and acoustic hydrology.
Marek Zreda Email | Google Scholar