Friday, July 8, 2016

Episode 324 (7-11-16): Gage, Stage, and Discharge

CLICK HERE to listen to episode audio (4:24)

Transcript of audio, notes on the audio, photos, and additional information follow below.

All Web addresses mentioned were functional as of 7-8-16.


From the Cumberland Gap to the Atlantic Ocean, this is Virginia Water Radio for the week of July 11, 2016.

This week, we feature another series of mystery sounds.  Have a listen for about 20 seconds, and see if you can guess what all of these sounds have in common.   And here’s a hint: the current time is perfect for coming up with an answer.

SOUNDS - ~ 23 sec

If you guessed stream flow measurements, you’re right!  You heard a stopwatch; students measuring a stream’s current; the small flow of Craig Creek, a James River tributary in southwestern Virginia; and the large flow of the James itself at Richmond.  All are aspects of the science and significance of measuring flowing water.  Past, present, and future volumes of water flowing in a given stream or river, and the height on the land surface that flowing water reaches, are valuable pieces of information for boaters, streamside property owners, water-supply systems, drought monitors, and many other individuals, groups, agencies, and businesses.   Scientists refer to the volume of flow over time in a stream or river as discharge, and the height of the water above a known reference level as stage.  Measurements of discharge are typically based on a given stream section’s current, or velocity, and the area of the channel at the location; or on a stream’s stage at a certain location and a known stage-discharge relationship at that location.

The science of streamflow measurement, part of the broader science of hydrology, has a long history, dating back to early civilizations in Asia, the Middle East, Greece, and Rome.  Some key advances in that history include measurements of current evolving from using watches and floating objects to today’s sophisticated electronic flowmeters; continuous, remote-sensing of data with instant electronic transmission to users; and computer modeling of data to clarify relationships among streamflow, landscapes, and climate.  In the 21st Century United States, stage and discharge measurements are provided by network of over 7000 gaging stations maintained by the U.S. Geological Survey and state partners, such as Virginia’s Department of Environmental Quality.  That network provides vital information for people who navigate streams and rivers, scientists who study water, and water-resources managers watching for signs of too much or too little flowing water.

We close with a musical interpretation of streamflow and weather data, from Waterviz, a water-cycle vizualization project by the U.S. Forest Service’s Hubbard Brook Experimental Forest in New Hampshire.

MUSIC - ~ 16 sec


For more Virginia water sounds, music, and information, visit us online at, or call us at (540) 231-5463. Virginia Water Radio is produced by the Virginia Water Resources Research Center, part of Virginia Tech’s College of Natural Resources and Environment.  Thanks to Stewart Scales for his banjo version of Cripple Creek to open and close the show.   In Blacksburg, I’m Alan Raflo, thanking you for listening, and wishing you health, wisdom, and good water.


Thanks to Lindsey Rustad and Marty Quinn, at the U.S. Forest Service’s Hubbard Brook Experimental Forest, for permission to use the Waterviz music heard in this episode.  Waterviz is a project of transforming hydrologic data, including streamflow data, through sonification—that is, using sound to represent the data, and by doing so, help people interpret or appreciate the data.  The excerpt used was from the sonification of four days of streamflow and weather data starting on February 23, 2016. More information on Waterviz is available online at The Waterviz project was featured in Virginia Water Radio Episode 283, 9-25-15.

Thanks to Kevin McGuire, associate director of the Virginia Water Resources Research Center, and to Mike Aust, Virginia Tech Department of Forest Resources and Environmental Conservation, for their help with this episode.

The Craig Creek sounds were recorded by Virginia Water Radio in Montgomery County, Va., on April 26, 2015.

Thanks to Michael Martz for providing the sounds of the James River at Richmond, recorded February 17, 2014.


Number of U.S. Geological Survey (USGS) stream gages in the United States, 1983-2009. The red line is the total number of gages, and the blue bars are the number of continuous, real-time gages. Image from the USGS National Streamflow Information Program, “2010 Update,” online at

Tower supporting cable used for taking discharge-related measurements at the U.S. Geological Survey (USGS) gaging station on the South Fork Shenandoah River near Lynnwood, Va. (Rockingham County), Dec. 16, 2009.

Identification sign on USGS stream-gaging station on the New River at Ivanhoe, Va. (Wythe County), Feb. 22, 2014.

Weir on Stroubles Creek on the Virginia Tech campus in Blacksburg, July 11, 2016.  Weirs and flumes are instream structures used to measure stream flow.


Used in Audio

Rafael Bras, “History of Hydrology,” January 1999 Horton Lecture at Massachusetts Institute of Technology (MIT), accessed online at

J. P. Nielsen and J. M. Norris, 2007, “From the River to You: USGS Real-Time Streamflow Information,” U.S. Geological Survey Fact Sheet 2007-3043, 4 pages; available online at

Vernon B. Sauer and D. Phil Turnipseed, 2010, “Stage measurement at gaging stations,” U.S. Geological Survey Techniques and Methods book 3, chap. A7, 45 pages; available online at

D. Phil Turnipseed, and Vernon B. Sauer, 2010, “Discharge measurements at gaging stations,” U.S. Geological Survey Techniques and Methods book 3, chap. A8, 87 pages; available at

U.S. Geological Survey (USGS), "National Streamflow Information Program," online at

USGS, “Streamgages: The Silent Superhero,” 5 min./4 sec. video, online at

USGS, “Water Science School/Surface Water Information,” online at; and “How Streamflow is Measured,” online at Click on the following links to explore specific topics. Measuring stream stage—the height of the water surface at a location along a stream or river. The discharge measurement—the quantity of water passing a location along a strea). The stage-discharge relation—the natural but often changing relation between stage and discharge.

For More Information about Flow in Streams, Rivers, and Watersheds
U.S. Geological Survey (USGS), “Mobile Water Data” Web site, online at

USGS WaterAlert, online at This offers users the opportunity to receive an e-mail or text message when conditions at specified stream/river gaging stations exceed the user’s specified water level.

USGS, “Water Resources of Virginia,” online at This is the home page for the USGS’ Virginia Water Science Center.

Virginia Department of Conservation and Recreation, “Virginia’s Major Watersheds,” online at


All Water Radio episodes are listed by category at the Index link above ( For episodes related to stream flow, please see the Science category, especially the following episodes:

Stream/river channel energy and patterns – Episode 248, 1/12/15;
Water cycle – Episode 191, 12/9/13; Episode 198, 1/27/14.

This episode may help with the following Virginia’s 2010 Science Standards of Learning (SOLs):

Grades K-6 Earth Patterns, Cycles, and Change Theme
3.9 – Water cycle, including sources of water, energy driving water cycle, water essential for living things, and water limitations and conservation.

Grades K-6 Earth Resources Theme
4.9 - Va. natural resources, including watersheds, water resources, and organisms.

Grades K-6 Living Systems Theme
6.7 - natural processes and human interactions that affect watershed systems; Va. watersheds, water bodies, and wetlands; and water monitoring.

Grades K-6 Matter Theme
6.5 – properties and characteristics of water.

Life Science Course
LS.6 - ecosystem interactions, including the water cycle, other cycles, and energy flow.

Physical Science Course
PS.8 – characteristics of sound waves, including technological applications of sound.

Earth Science Course
ES.8 - influences by geologic processes and the activities of humans on freshwater resources, including identification of groundwater and major watershed systems in Virginia.

The episode may also help with the following Virginia 2008 Social Studies SOLs:

World Geography Course
WG.2 - how selected physical and ecological processes shape the Earth’s surface, including how humans influence their environment and are influenced by it.
WG.10 - cooperation among political jurisdictions to solve problems and settle disputes.

The episode may also help with Virginia 2013 Music SOLs at various grade levels that call for “examining the relationship of music to the other fine arts and other fields of knowledge.”

Virginia’s SOLs are available from the Virginia Department of Education, online at