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ESE 200
Water in the Earth System
Learning goals
Know where the water is systematically and globally
Understand groundwater’s role in the hydrologic cycle Water table, aquifer, stocks versus flows,
sustainability, renewability, contamination Be able to describe the major water users
in developed and developing countries, and how these patterns might change in the future.
Numbers
One gallon (G) is ~4 liters (L)… One cubic meter is 1000 liters One cubic kilometer is 1012 liters
Where’s all the water stored?
Where’s all the water moving?
Individual water use
What are the biggest ways that you directly use water each day (e.g. drink it from faucet)?
List your top three
Nevada e.g.
Which sectors of society are big users of water?
Which sectors of society are big users of water?
Who uses the most?
One view…
Most water use is agricultural
World trend
Note size of green wedge
US trend is different
Indirect water use by individuals
So most water use in US is indirect
What are the biggest indirect uses of water in your daily life?
Imbedded water
Imbedded water
Small coffee of the day = 50 gallons of water!
Small coffee of the day = 50 gallons of water!
¼ pounder patty = 500 gallons of water
Imbedded water
Who has the water, globally?
Proportion of water resources
Size of country represents size of water resource
Proportion of water use
Size of country represents use of water
Which countries/regions are water stressed?
water resource
water use
Who has the water, globally?List regions that are
•Water stressed•Water rich
Which countries/regions are water stressed?
water resource
water use
Who has the water, globally?List regions that are
•Water stressed•Water rich
Water use in Punjab
Watch the video
1. What is the central issue/problem?2. What is the policy failure that is
contributing to the problem?
Groundwater and the Water Table
2% to 25% of rainfall
Digging a well for water
What are some things to keep in mind?
Where is a good place? Or a bad place?
What influences the success of the well?
Come up with some ideas!
The Water Table
Water percolates into the earth because of gravity
Deeper rocks are not very permeable, so water only percolates to a depth of 5 to 10 km
The water table marks the surface of this underground trapped water
The Water Table Below the water table
the rock is saturated with water (i.e. the pores are completely filled)
The Water Table Below the water table
the rock is saturated with water (i.e. the pores are completely filled)
Lakes mark the water tableLakes mark the water table
Ground water movement Water moves slowly through the ground, in
response to pressure and elevation The water always flows in the direction of the
slope of the water table
Streams and Ground Water
Streams can either gain or lose water to ground water sources
Impact of groundwater withdrawal
Southern India Why would increases in the number
of boreholes decrease the flow of the river in summer?
Is there a policy failure?
Aquifers Aquifers are regions of saturated rock in which
water can move easily (i.e. are permeable) Excellent sites for wells
Generally Generally sedimentary permeable, sedimentary permeable, igneous not. igneous not.
Aquifers
Igneous can be Igneous can be permeable if it has the permeable if it has the right pattern of cracks right pattern of cracks for the water to flow for the water to flow throughthrough
Aquifers are regions of saturated rock in which water can move easily (i.e. are permeable)
Excellent sites for wells
Groundwater
Should we consider groundwater a renewable resource?
tps
Groundwater
Should we consider groundwater a renewable resource?
Yes: continually recharged
No: Use can exceed rate of recharge Can be contaminated
Groundwater:recharge rates differ by depth
Flow lines
Confining beds
WellsWater table
Millennia
Centuries
Decades
Years
Days
Dischargearea
Unconfinedaquifer
Confinedaquifers
Water use in Spain
Watch this
And consider: 1. What sector is the biggest user of
Spanish water?2. Is there a Tragedy of the Commons
problem here?3. What are the policies concerning
water use, and are they making the problem better or worse?
Aquifers in Illinois
Closest to surface
Aquifers in Illinois
Within 500 ft of surface
Aquifers in Illinois
Deeper than 500 ft from surface
Aquifers in Illinois
Sand and gravel wells Why no
bedrock wells in Champaign?
Aquifers in Illinois
Sustainable?
Aquifers in Illinois
Sustainable?Groundwater recharge is arguably
one of the least understood and quantified components of the hydrologic cycle. It cannot be measured directly, is highly variable in space and time, and must be inferred…
Illinois State Water Survey
Aquifers in Illinois
Sustainable?Groundwater recharge is arguably
one of the least understood and quantified components of the hydrologic cycle. It cannot be measured directly, is highly variable in space and time, and must be inferred…
Illinois State Water Survey
Illinois uses over one billion gallons of ground water (per day)… Illinois aquifers have an estimated combined potential yield of approximately 7 billion gallons per day…
Ground Water Contamination
Water table is raised under a landfill (higher surface and permeable trash)
Ground Water Contamination
Water table is raised under a landfill (higher surface and permeable trash)
Soluble pollution moves in the same direction as the groundwater flow
Wells
As wells pump water, they locally lower the water table
Groundwater Contamination Pumping wells can “attract” pollution by
changing the surface gradient of the water table
Pumping wells can “attract” pollution by changing the surface gradient of the water table
Groundwater Contamination
Beyond society: why else is water important?
Indian waterways List all the ways in which human
activities/policies are degrading the rivers as habitat for the reptiles discusses by the presenter.
Western Ghats
Future needs?
Is this extra water available?
UN
Predicted water availability
UN projection
Predicted water availability
UN projection
Currently, US uses ~4000 cubic meters/person/year
Predicted water scarcity
Predicted water scarcity
Each group: come up with one policy (large or small) that would minimize the impact of water scarcity on one of the red areas.Simply estimate the major cost and benefit(s).
Virtual Water
Which is harder to transport?1. 3,400 cubic meters of water2. 1 metric tonne of rice
Virtual Water
Which is harder to transport?1. 3,400 cubic meters of water2. 1 metric tonne of rice
3,400 tonnes in weight!
3,400 kilos of water needed for each kilo of rice produced
Virtual Water
Water rich areas can trade water intensive products to water poor areas Water itself is too bulky to trade
Science media center
Virtual Water: caveat
Treats all freshwater as the same, but not so in reality groundwater rainwater lake water recycled water treated municipal water…
e.g. 140 litres of harvested water (well, rain, dam, etc.) and 0.25 litres of tap water
Virtual Water trading
Water rich areas can trade water intensive products to water poor areas Water itself is too bulky to trade
Virtual Water trading
Which countries import and export virtual water?
tps
Virtual Water trading
Which countries import and export virtual water?
"Among the biggest net exporter countries of virtual water are the U.S., Canada, Thailand, Argentina, India, Vietnam, France and Brazil. Some of the largest net import countries are Sri Lanka, Japan, the Netherlands, South Korea, China, Spain, Egypt, Germany and Italy."
Daniel Zimmer, World Water Council, 2003
Virtual Water trade
Doesn’t quite match, this data from 1997
Virtual Water trade
Doesn’t quite match, this data from 1997
Yemen
Yemen
Organization Survey Ranking
Institute for Economics and Peace Global Peace Index119 out of
144
United Nations Development Programme
Human Development Index
140 out of 182
Transparency InternationalCorruption Perceptions
Index154 out of
180
A county with problems: semi civil-war, undemocratic, poor:
Poor countries, poor policies Yemen:
receives 200 cubic m/person/yr, below the international water poverty line of 1,000 cubic m/person/yr
Yemeni Policies Prime Ag. sites used for
Qat, a chewed drug As a consequence:
Imports 80% of food 1000’s of illegal wells
'You know it's ready to harvest when the top stalk has two buds' ... Yemen's Nabil Ali Rafik, 17, shows off his qat plants in Wadi Dahr. Photograph: Hugh Macleod, Guardian
Yemeni Policies
Yemeni government subsidizes diesel Diesel is used to power well pumps
Unintended consequence: Over-extraction
Yemeni Aquifers 4 gallons withdrawn from main aquifer for
every gallon replenished Some wells have been completely
contaminated by sea water Untreated sewage and oil contamination
are also problems
Yemeni Society Capital, Sana'a, 7%/yr pop. growth, will
run out of water by 2017 1/2 of pop. lives on less than $2 a day
Already has to import clean water
Summary
Most global water use is agricultural Future shortage is agricultural Trade can satisfy local demand: “virtual water”
Most individual water use is indirect Groundwater is an important part of
supply Groundwater is dropping in many places
Increasing water costs, decreasing sustainability/renewability, contamination threat