Water ResourcesWater ResourcesEssential uses for sustaining lifeEssential uses for sustaining life

in all its formsin all its forms

Breck BowdenPatrick Professor of Watershed Science & Planning

Rubenstein School of Environment & Natural Resourceshttp://www.uvm.edu/~wbowden

Take Home MessagesTake 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 waterUnusual 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 waterThe ‘phases’ of waterP

ress

ure

(atm

osph

eres

)

10,000

1,000

100

10

1

.01

.001

.0001-20 0 20 40 60 80 100 120

LiquidSolid

Vapor

Temperature (degrees Celsius)

• Sea level

• Denver

The ‘phases’ of waterThe ‘phases’ of waterP

ress

ure

(atm

osph

eres

)

10,000

1,000

100

10

1

.01

.001

.0001-20 0 20 40 60 80 100 120

LiquidSolid

Vapor

Temperature (degrees Celsius)

• Gutterson Field House

• 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

• Denver

• Sea level

Hockey player

Dullskates

Glaciers

The ‘phases’ of waterThe ‘phases’ of waterP

ress

ure

(atm

osph

eres

)

10,000

1,000

100

10

1

.01

.001

.0001-20 0 20 40 60 80 100 120

LiquidSolid

Vapor

Temperature (degrees Celsius)

• Gutterson Field House

• Most other substances

• Denver

• Sea level

Return to Characteristics

Continue

Why do some objects float?Why do some objects float?

• Mass is not the same thing as weight

• Density = mass/volume (g/cm3)

> = < =

Why don’t lakes freezeWhy don’t lakes freeze from the bottom up? from the bottom up?

15oC

10oC

Why don’t lakes freezeWhy don’t lakes freeze from the bottom up? from the bottom up?

12oC

10oC

Why don’t lakes freezeWhy don’t lakes freeze from the bottom up? from the bottom up?

10oC

10oC

Why don’t lakes freezeWhy don’t lakes freeze from the bottom up? from the bottom up?

3.97oC

10oC

Why don’t lakes freezeWhy don’t lakes freeze from the bottom up? from the bottom up?

3.97oC

3.97oC

Why don’t lakes freezeWhy don’t lakes freeze from the bottom up? from the bottom up?

1oC

3.97oC

Why don’t lakes freezeWhy don’t lakes freeze from the bottom up? from the bottom up?

0oC

3.97oC

The basic structure of waterThe basic structure of water

Density changes with phaseDensity changes with phase

Free molecules in liquid Fixed molecules in solid

Return to Characteristics

Continue

We often ‘use’ water without We often ‘use’ water without realizing itrealizing it

Miller (2004)Fig. 13.6, p. 298

1 automobile

1 kilogramcotton

1 kilogramaluminum

1 kilogramgrain-fed beef

1 kilogramrice

1 kilogramcorn

1 kilogrampaper

1 kilogramsteel

400,000 liters(106,000 gallons)

10,500 liters(2,400 gallons)

9,000 liters(2,800 gallons)

7,000 liters(1,900 gallons)

5,000 liters(1,300 gallons)

1,500 liters(400 gallons)

880 liters(230 gallons)

220 liters(60 gallons)

Typical Water Use in the HomeTypical Water Use in the Home

How much water do you use?

Water Use Trends in the USWater Use Trends in the US

In Vermont: 187 gal/person/day (USGS data)

Water Use Water Use World WideWorld Wide

Assessment Assessment & Forecast& Forecast

UNESCO (2000)

We use more water than mostWe use more water than most

Environment Canada (http://www.ec.gc.ca/water/e_main.html)

What is the incentive to conserve?What is the incentive to conserve?

Environment Canada (http://www.ec.gc.ca/water/e_main.html)

We pay lessWe pay lessfor water for water

than almost than almost anyone elseanyone else

Environment Canada(http://www.ec.gc.ca/water/e_main.html)

Where do Where do we get we get

the water the water we use?we use?

USGS Water Science Web Site

Where does all the water go?Where does all the water go?

Miller (2004)Fig. 19.5, p. 482

Discharge of untreatedmunicipal sewage

(nitrates and phosphates)

Nitrogen compoundsproduced by cars

and factories

Discharge of treatedmunicipal sewage

(primary and secondarytreatment:

nitrates and phosphates)

Discharge of detergents

( phosphates)

Natural runoff(nitrates andphosphates

Manure runoffFrom feedlots(nitrates andPhosphates,

ammonia)

Dissolving of nitrogen oxides

(from internal combustionengines and furnaces)

Runoff and erosion(from from cultivation,mining, construction,

and poor land use)

Runoff from streets,lawns, and construction

lots (nitrates andphosphates)

Lake ecosystemnutrient overload

and breakdown of chemical cycling

Stormwater

Take Home MessagesTake 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?

• USGS’s Water Science Web Site

• EPA’s Surf Your Watershed

• EPA’s Watershed Academy

• Lake Champlain Basin Program (Atlas)

Useful WebsitesUseful Websites

http://www.epa.gov/owow/watershed/wacademy/

http://cfpub.epa.gov/surf/locate/index.cfm

http://wwwga.usgs.gov/edu/mwater.html

http://www.lcbp.org/

Thank you!Thank you!