Water Resources
Essential uses for sustaining life
in all its forms
Breck Bowden
Patrick Professor of Watershed Science & Planning
Rubenstein School of Environment & Natural Resources
http://www.uvm.edu/~wbowden
Take Home Messages
• Water is a wonderfully strange compound.
• We use a lot of water, often without knowing it.
• Water management is an issue of critical
importance: the Stormwater example.
• Why use a ‘watershed’ approach?
Unusual characteristics of water
• Why is it possible to skate on ice?
[key concept: phases]
• Why don’t lakes freeze from the bottom?
[key concept: density]
To Water Use
To Water Quality
The ‘phases’ of water
Pressure (atmospheres)
10,000
• Sea level
1,000
• Denver
100
10
Liquid
Solid
1
.01
Vapor
.001
.0001
-20
0
20
40
60
80
Temperature (degrees Celsius)
100
120
The ‘phases’ of water
Pressure (atmospheres)
10,000
• Sea level
1,000
Glaciers
100
• Denver
Hockey player
10
Dull
skates
Solid
Liquid
• Gutterson Field House
1
.01
Vapor
.001
.0001
-20
0
20
40
60
80
100
120
Temperature (degrees Celsius)
•
•
•
•
1 atmosphere = ~14.7 lbs per square inch
1 hockey player weighs about 190 lbs
1 hockey blade is about 10” long and <0.01” wide = <0.1 square inches
 applied pressure is 190 lbs/0.1 in2 = 1900 psi = ~130 atms
The ‘phases’ of water
Pressure (atmospheres)
10,000
• Sea level
1,000
• Denver
100
10
Liquid
Solid
• Gutterson Field House
1
• Most other substances
.01
Vapor
.001
.0001
-20
0
20
40
60
80
100
120
Temperature (degrees Celsius)
Return to Characteristics
Continue
Why do some objects float?
• Mass is not the same thing as weight
• Density = mass/volume (g/cm3)
>
=
<
=
Why don’t lakes freeze
from the bottom up?
15oC
10oC
Why don’t lakes freeze
from the bottom up?
12oC
10oC
Why don’t lakes freeze
from the bottom up?
10oC
10oC
Why don’t lakes freeze
from the bottom up?
3.97oC
10oC
Why don’t lakes freeze
from the bottom up?
3.97oC
3.97oC
Why don’t lakes freeze
from the bottom up?
1oC
3.97oC
Why don’t lakes freeze
from the bottom up?
0oC
3.97oC
The basic structure of water
Density changes with phase
Free molecules in liquid
Fixed molecules in solid
Return to Characteristics
Continue
We often ‘use’ water without
realizing it
1 automobile
400,000 liters
(106,000 gallons)
1 kilogram
cotton
10,500 liters
(2,400 gallons)
1 kilogram
aluminum
9,000 liters
(2,800 gallons)
1 kilogram
grain-fed beef
7,000 liters
(1,900 gallons)
1 kilogram
rice
1 kilogram
corn
1 kilogram
paper
1 kilogram
steel
5,000 liters
(1,300 gallons)
1,500 liters
(400 gallons)
880 liters
(230 gallons)
220 liters
(60 gallons)
Miller (2004)
Fig. 13.6, p. 298
Typical Water Use in the Home
How much water do you use?
Water Use Trends in the US
In Vermont: 187 gal/person/day (USGS data)
Water Use
World Wide
Assessment
& Forecast
UNESCO (2000)
We use more water than most
Environment Canada (http://www.ec.gc.ca/water/e_main.html)
What is the incentive to conserve?
Environment Canada (http://www.ec.gc.ca/water/e_main.html)
We pay less
for water
than almost
anyone else
Environment Canada
(http://www.ec.gc.ca/water/e_main.html)
Where do
we get
the water
we use?
USGS Water Science Web Site
Where does all the water go?
Discharge of untreated
municipal sewage
(nitrates and phosphates)
Nitrogen compounds
produced by cars
and factories
Discharge of
detergents
( phosphates)
Discharge of treated
municipal sewage
(primary and secondary
treatment:
nitrates and phosphates)
Lake ecosystem
nutrient overload
and breakdown of
chemical cycling
Dissolving of
nitrogen oxides
(from internal combustion
engines and furnaces)
Stormwater
Natural runoff
(nitrates and
phosphates
Manure runoff
From feedlots
(nitrates and
Phosphates,
ammonia)
Runoff from streets,
lawns, and construction
lots (nitrates and
phosphates)
Runoff and erosion
(from from cultivation,
mining, construction,
and poor land use)
Miller (2004)
Fig. 19.5, p. 482
Take Home Messages
• Water is a wonderfully strange compound.
• We use a lot of water, often without knowing it.
• Water management is an issue of critical
importance: the Stormwater example.
• Why use a ‘watershed’ approach?
Useful Websites
• USGS’s Water Science Web Site
http://wwwga.usgs.gov/edu/mwater.html
• EPA’s Surf Your Watershed
http://cfpub.epa.gov/surf/locate/index.cfm
• EPA’s Watershed Academy
http://www.epa.gov/owow/watershed/wacademy/
• Lake Champlain Basin Program (Atlas)
http://www.lcbp.org/
Thank you!