Water Resources

1
Water Resources

• Chapter 13

2
Questions for Today

• Why is water so important?
• Does everyone have access to clean and healthy
  water
• Describe the three major zones of Groundwater.
• What are the major problems associated with
  Freshwater in the US?
• What is Drought and what are the problems
  associated with Drought?
• Who owns all the freshwater?

3
Freshwater Is an Irreplaceable Resource That We
Are Managing Poorly (1)

• Why is water so important?
• Earth as a watery world 71 (mostly Salt)
• 60 of yourself is made from water
• Freshwater availability 0.024
• Hydrologic cycle
• Movement of water in the seas, land, and air
• Driven by solar energy and gravity
• Water pollution
• Degradation of the Worlds Water Supply
• Partly Because its Cheap
• Taken For Granted

4
Freshwater Is an Irreplaceable Resource That We
Are Managing Poorly (2)

• Access to water is
• A global health issue
• Sanitation
• 1.6 million people died in 2007
• An economic issue
• Helps reduce poverty and produces food and energy
• A womens and childrens issue
• In developing countries, it is their job to carry
  water back home
• A national and global security issue
• Tension between shared resources

5
Girl Carrying Well Water over Dried Out Earth
during a Severe Drought in India
6
Most of the Earths Freshwater Is Not Available
to Us

• People divided into
• Water haves
• Those that have a readily availably clean and
  healthy water supply
• For instance
• Canada has 0.5 of the worlds people but has 20
  of the worlds water
• Water have-nots
• Those that do not access to clean, fresh water
• For instance
• China has 20 of the worlds people, but only 7
  of the worlds supply of freshwater

7
We Get Freshwater from Groundwater and Surface
Water (1)

• Ground water
• Water found in the pores between soil, gravel and
  rock held between an impenetrable rock layer
• Zone of saturation
• The point at which the groundwater is completely
  filled
• Water table
• The Top of the Ground water zone
• Falls in dry weather or unsustainable harvesting
• Rises in Wet Weather
• Aquifers
• Natural recharge from precipitation and
  percolation
• Lateral recharge from a nearby river or stream
• Both Recharge slowly

8
We Get Freshwater from Groundwater and Surface
Water (2)

• Surface Water Most Important Water Resource
• Lakes, Rivers, Streams
• Surface runoff non-evaporated precipitation
• Watershed (drainage) basin
• A collection area for Surface water

9
Natural Capital Groundwater System Unconfined
and Confined Aquifer
10
Unconfined Aquifer Recharge Area
Evaporation and transpiration
Evaporation
Precipitation
Confined Recharge Area
Runoff
Flowing artesian well
Well requiring a pump
Stream
Water table
Infiltration
Lake
Infiltration
Unconfined aquifer
Less permeable material such as clay
Confined aquifer
Confining impermeable rock layer
Fig. 13-3, p. 316
11
We Use a Large and Growing Portion of the Worlds
Reliable Runoff

• 2/3 of the surface runoff lost by seasonal
  floods
• 1/3 runoff usable
• Domestic 10
• Agriculture 70
• Industrial use 20
• Fred Pearce, author of When the Rivers Run Dry
• Takes 450,000 liters or 2,400 bathtubs of water
  to produce a car
• 140 liters to produce a cup of coffee
• 25 bathtubs to produce a T-shirt

12
Case Study Freshwater Resources in the United
States

• More than enough renewable freshwater, unevenly
  distributed
• Eastern states have more rain than western and
  southwestern states
• The three rainiest cities are
• Mobile, AL
• Pensacola, FL
• New Orleans, LA
• What are the most serious water problems in the
  US?
• Floods
• Pollution
• Drought when precipitation is at least 70
  lower and evaporation is higher than normal.

13
Average Annual Precipitation and Major Rivers,
Water-Deficit Regions in U.S.
14
Fig. 13-4a, p. 317
15
Fig. 13-4b, p. 317
16
Long-Term Severe Drought Is Increasing

• Causes
• Extended period of below-normal rainfall
• Diminished groundwater
• Harmful environmental effects
• Dries out soils
• Reduces stream flows
• Decreases tree growth and biomass
• Lowers net primary productivity and crop yields
• Shift in biomes

17
In Water-Short Areas Farmers and Cities Compete
for Water Resources

• 2007 National Academy of Science study
• Increased corn production in the U.S. to make
  ethanol as an alternative fuel
• Decreasing water supplies
• Aquifer depletion
• Increase in pollution of streams and aquifers

18
Who Should Own and Manage Freshwater Resources?
(1)

• Most water resources
• Owned by governments
• Managed as publicly owned resources
• Veolia and Suez French companies
• Buy and manage water resources
• Successful outcomes in many areas

19
Who Should Own and Manage Freshwater Resources?
(2)

• Bechtel Corporation
• Poor water management in Bolivia
• Potential problems with full privatization of
  water resources
• Financial incentive to sell water not conserve
  it
• Poor will still be left out