Monday, July 8, 2019

Episode 480 (7-8-19): Rethinking Water Cycle Diagrams

Click to listen to episode (4:53).

Sections below are the following:
Transcript of Audio
Audio Notes and Acknowledgments
Extra Information
Related Water Radio Episodes
For Virginia Teachers (Relevant SOLs, etc.).

Unless otherwise noted, all Web addresses mentioned were functional as of 7-5-19.


From the Cumberland Gap to the Atlantic Ocean, this is Virginia Water Radio for the week of July 8, 2019.

MUSIC – ~8 sec

This week, that excerpt of “Rain Refrain,” by Torrin Hallett, opens an episode on a recently published scientific paper challenging the typical depiction of a vital, worldwide cycle.  Have a listen for about 30 seconds to some mystery sounds related to this cycle, see if you know any of three names for the cycle.


If you guessed the water cycle, the hydrologic cycle, or the hydrological cycle, you’re right!  You heard sounds of some of the components typically included in descriptions or diagrams of the water cycle: rainfall, representing precipitation; a river, representing surface water and flow; coastal waves, representing the ocean; and water flowing from a spring, representing groundwater storage and movement.  The final sound you heard—a household faucet—represents the role of humans in the water cycle, an aspect not as often included in water cycle diagrams.  The exclusion of a human component from water cycle diagrams is one of the main issues raised in a July 2019 scientific article entitled, “Human domination of the global water cycle absent from depictions and perceptions.”  Published in the journal Nature Geoscience, the paper was authored by 23 scientists from seven U.S. research institutions, including Virginia Tech, and from six other countries.

The researchers examined several dozen recent studies of the global water cycle to identify and quantify 16 sources of water, called “pools,” and 16 water-movement processes, called “fluxes.”  They then compared those findings to over 400 water cycle diagrams from several countries, including the United States.  The researchers found that the majority of water cycle diagrams didn’t include, or inaccurately represented, several components or principles identified in the scientific studies.  As already noted, one main finding was the widespread exclusion of human interactions with water.  Other components that the researchers assert were underrepresented include precipitation over the ocean [p. 535 of the research paper]; the amount of fresh water that is actually available for human use [p. 535]; large water bodies with no surface outlet, such as the Caspian Sea in western Asia [p. 539]; and uncertainty and variation over time in estimates of water cycle components [p. 535].

The researchers suggest that inaccuracies in water cycle depictions can, quote, “reflect and reinforce the misunderstanding of global hydrology by policymakers, researchers, and the public.”  Conversely, they assert that improving the accuracy of widely used water cycle diagrams would be, in the researchers’ words, “an important step towards equitable water governance, sustainable development, and planetary thinking.”

Thanks to the U.S. Fish and Wildlife Service for the ocean sounds, and to Torrin Hallett for this week’s music. We close by letting part of the water cycle have the last sound.

SOUND - ~ 7 sec – thunder and rain.


Virginia Water Radio is produced by the Virginia Water Resources Research Center, part of Virginia Tech’s College of Natural Resources and Environment.  For more Virginia water sounds, music, or information, visit us online at, or call the Water Center at (540) 231-5624.  Thanks to Stewart Scales for his banjo version of Cripple Creek to open and close this show.  In Blacksburg, I’m Alan Raflo, thanking you for listening, and wishing you health, wisdom, and good water.


The sounds heard in this episode were recorded by Virginia Water Radio (except as noted below), as follows:
rainfall in Blacksburg, Va. (Montgomery County), 9/28/16;
North Fork Roanoke River, Montgomery County, Va., 4/6/12;
spring water near Pearisburg, Va. (Giles County), 9/30/18;
household water faucet in Blacksburg, Va., 7/6/19.

The coastal waves sounds recording was accessed at the U.S. Fish and Wildlife Service’s National Digital Library/Audio Collection, online at, as of 7/8/19.

“Rain Refrain” is copyright 2016 by Torrin Hallett, used with permission.  Torrin is a 2018 graduate of Oberlin College and Conservatory in Oberlin, Ohio; as of 2019, he is a graduate student in Horn Performance at Manhattan School of Music in New York.  More information about Torrin is available online at  This music was also featured in Episode 338, 10-17-16, on rainfall measurements; and Episode 455, 1-14-19, on record Virginia precipitation in 2018.  Thanks very much to Torrin for composing the piece for Virginia Water Radio.

Following are links to other episodes featuring music composed by Torrin Hallett.

Episode 343, 11-21-16, on the Wild Turkey – “Turkey Tune”;
Episode 349, 1-2-17, on the New Year – “New Year’s Water”;
Episode 362, 4-3-17, on hail; Episode 377, 7-17-17, on clouds; Episode 438, 9-17-18 – on hurricane basic facts and history; and Episode 468, 4-15-19, on stormwater and storm-drain stenciling – “Storm,” from “Au Naturale.”
Episode 369, 5/22/17 and Episode 423, 6/2/18, on the upcoming Atlantic tropical storm seasons in 2017 and 2018, respectively; and Episode 438, 9-17-18 – on hurricane basic facts and history– “Tropical Tantrum.”

Click here if you’d like to hear the full version (1 min./11 sec.) of the “Cripple Creek” arrangement/performance by Stewart Scales that opens and closes this episode. More information about Mr. Scales and the group New Standard, with which Mr. Scales plays, is available online at


A Sample of Water Cycle Diagrams

Source: National Weather Service, “Jet Stream/The Hydrologic Cycle,” online at

Source: National Oceanic and Atmospheric Administration (NOAA), “Education/Water Education/The Water Cycle,” online at

Source: U.S. Geological Survey, “Water Science School/The Water Cycle for Schools,” online at

Source: U.S. Geological Survey, “Water Science School/The Fundamentals of the Water Cycle,” online at


From the U.S. Geological Survey (USGS), “Water Science School/The Water Cycle for Adults and Advanced Students,” online at

A (Very) Quick Summary of the Water Cycle
“Where does all the Earth's water come from? Primordial Earth was an incandescent globe made of magma, but all magmas contain water.  Water set free by magma began to cool down the Earth's atmosphere, until it could stay on the surface as a liquid.  Volcanic activity kept and still keeps introducing water in the atmosphere, thus increasing the surface- and groundwater volume of the Earth.

“The water cycle has no starting point.  But, we'll begin in the oceans, since that is where most of Earth's water exists.  The sun, which drives the water cycle, heats water in the oceans.  Some of it evaporates as vapor into the air. Ice and snow can sublimate directly into water vapor.  Rising air currents take the vapor up into the atmosphere, along with water from evapotranspiration, which is water transpired from plants and evaporated from the soil.  The vapor rises into the air where cooler temperatures cause it to condense into clouds.

“Air currents move clouds around the globe, cloud particles collide, grow, and fall out of the sky as precipitation.   Some precipitation falls as snow and can accumulate as ice caps and glaciers, which can store frozen water for thousands of years.  Snowpacks in warmer climates often thaw and melt when spring arrives, and the melted water flows overland as snowmelt.

“Most precipitation falls back into the oceans or onto land, where, due to gravity, the precipitation flows over the ground as surface runoff.  A portion of runoff enters rivers in valleys in the landscape, with streamflow moving water towards the oceans.  Runoff, and groundwater seepage, accumulate and are stored as freshwater in lakes.  Not all runoff flows into rivers, though.  Much of it soaks into the ground as infiltration.  Some water infiltrates deep into the ground and replenishes aquifers (saturated subsurface rock), which store huge amounts of freshwater for long periods of time.

“Some infiltration stays close to the land surface and can seep back into surface-water bodies (and the ocean) as groundwater discharge, and some groundwater finds openings in the land surface and emerges as freshwater springs.  Over time, though, all of this water keeps moving, some to reenter the ocean, where the water cycle ‘ends’…[or] ‘begins.’”


Benjamin W. Abbott et al., “Human domination of the global water cycle absent from depictions and perceptions,” Nature Geoscience, Vol. 12, July 2019, pages 533-540; accessed online at

Wilfried Brutsaert, Hydrology—An Introduction, Cambridge University Press, Cambridge, UK, 2005.

Encyclopedia Britannica, “Caspian Sea,” online at; and “Great Salt Lake,” online at  The Caspian Sea and the Great Salt Lake are examples of inland water bodies that do not drain eventually to the ocean; such water bodies are referred to as “endorheic basins or endorheic lakes.”  See also the United Nations Environment Programme reference below.

National Weather Service, “Jetstream—An Online School for Weather/The Hydrologic Cycle,” online at

Princeton University Geophysical Fluid Dynamics Laboratory, “Hydrological Cycle and Atmospheric Circulation,” online at

United Nations Environment Programme, “Endorheic Lakes: Waterbodies That Don’t Flow to the Sea,” no date indicated, online at

U.S. Geological Survey, “Water Science School/A Comprehensive Study of the Water Cycle,” online at

All Water Radio episodes are listed by category at the Index link above (  See particularly the “Science” subject category.

Following are links to some other episodes on the water cycle.

Episode 191, 12/9/13 – The Water Cycle
Episode 198, 1/27/14 – Hydrologists Sing and Study “Where Does the Water Go?”
Episode 365, 4/24/17 – Where’s Stormwater Get Started? Ask a Middle Schooler!


The episode—the audio, extra information, or sources—may help with the following Virginia Standards of Learning (SOLs).

2013 Music SOLs

SOLs at various grade levels that call for “examining the relationship of music to the other fine arts and other fields of knowledge.”

2010 Science SOLs

Grades K-6 Scientific Investigation, Reasoning, and Logic Theme
3.1, 4.1, 5.1, and 6.1 – Gathering and analyzing data, and current applications to reinforce science concepts.

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.
6.9 – public policy decisions related to the environment (including resource management and conservation, land use decisions, hazard mitigation, cost/benefit assessments).

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

Grades K-6 Matter Theme
6.5 – properties and characteristics of water and its roles in the natural and human environment.

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

Physical Science Course
PS.1 – understanding scientific reasoning, logic, and the nature of science, including current applications to reinforce science concepts.

Earth Science Course
ES.1 – current applications to reinforce science concepts.
ES.8 – influences by geologic processes and the activities of humans on freshwater resources, including identification of groundwater and major watershed systems in Virginia, with reference to the hydrologic cycle.

Physics Course
PH.1 – current applications to reinforce science concepts.
PH.2 – analyzing and interpreting data.
PH.3 – nature and practice of science.

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

Following are links to Water Radio episodes (various topics) designed especially for certain K-12 grade levels.

Episode 250, 1-26-15 – on boiling, for kindergarten through 3rd grade.
Episode 255, 3-2-15 – on density, for 5th and 6th grade.
Episode 282, 9-21-15 – on living vs. non-living, for kindergarten.
Episode 309, 3-28-16 – on temperature regulation in animals, for kindergarten through 12th grade.
Episode 333, 9-12-16 – on dissolved gases, especially dissolved oxygen in aquatic habitats, for 5th grade.
Episode 403, 1-15-18 – on freezing and ice, for kindergarten through 3rd grade.
Episode 404, 1-22-18 – on ice on ponds and lakes, for 4th through 8th grade.
Episode 406, 2-5-18 – on ice on rivers, for middle school.
Episode 407, 2-12-18 – on snow chemistry and physics, for high school.