Eses%20200%20water 1

transcript

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?

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

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?

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

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

Within 500 ft of surface

Deeper than 500 ft from surface

Sand and gravel wells Why no

bedrock wells in Champaign?

Sustainable?

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

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

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?

Predicted water availability

UN projection

Predicted water availability

UN projection

Currently, US uses ~4000 cubic meters/person/year

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

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

Organization Survey Ranking

Institute for Economics and Peace Global Peace Index119 out of

United Nations Development Programme

Human Development Index

140 out of 182

Transparency InternationalCorruption Perceptions

Index154 out of

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

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