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Unit 3 water
Unit 3
water
October 24
1. Turn in your hw (outline of pg 313-321)
2. Bellwork: Brainstorm all of the ways you use water!
3. What’s your learning goal?
Water Availability
Demo
Water Availability
vetstreet
Herald Time OnlineMake 2 groups
places with excess water
and places with water scarcity.
Provide reasons why this disparity exists.
Current Droughts & Water Scarcity
https://www.drought.gov/gdm/current-conditions
http://www.nytimes.com/2016/02/13/science/two-thirds-of-the-world-faces-severe-water-shortages.html?_r=0
Assignment for the week
Over the next 3 days - keep a log of all of your water use
We’re going to use to it to see how much we use as a class and where we can all cut back
Who should own water?
Recall Tragedy of the Commons? people acting in their own self interest will eventually deplete a shared limited resource, even when it’s not in anyone’s long term interest for this to happen
Discuss and take a stance - Should private companies own or manage most of the world’s water resources? Consider the examples of SW U.S., the Middle East, Pudong, Cochabamba, and Guayaquil in your answer.
Review
What are the causes
and effects of water
shortage?
October 24 in Review
Learning Goal: What are the causes and effects of water shortage?
Causes: wasteful water use, overuse of common water source, drought, dry climate
Effects: loss of vegetation/agriculture, starvation due to poor crop yields and death of livestock, dehydration, diseases due tpo poor hygiene
October 25
1. Turn in your hw (outline of pg 321-329)2. Bellwork: Read Dams & Salmon with your shoulder
partner and create a flowchart of the causes and effects of building dams on the Klamath River.Then, use the flowchart to give evidence to your prediction about what will happen in 2020 when the dam removal project is expected to be completed.
3. What’s your learning goal?
October 25
1. When and why was the dam built?2. What happened to the salmon? Residents?
Fishing industry? Native Americans? Power companies? Anyone else?
3. What was the tipping point for removing it?4. What will happen when it is removed?
Three Gorges Dam
Pros Cons
Can generate 22,500 MW
Increases shipping capacity
Reduces downstream floods
Limits greenhouse gas emissions
EXPENSIVE
Flooded archeological and cultural sites
Displaced 1.3 million people
Changes ecosystems
Increased chances of landslides
Aquifer Depletion
1. Lowering of water table- leads to a cone of depression
2. Increased costs for the user- an advantage of artesian wells
3. Reduction of water in lakes and streams4. Land subsidence5. Deterioration of water quality
- such as saltwater intrusion
An area lacking groundwater due to rapid withdrawal by a well. Meaning, rapid pumping of a deep well can cause adjacent, shallower
wells to go dry
Cone of Depression
Artesian Wells
A well is drilled into a confined aquifer and the water rises by natural pressure difference
an infiltration of saltwater in an area where groundwater pressure has been reduced
from an extensive drilling of wells, common in coastal areas
Saltwater Intrusion
Review
Talk with your group…
Could the Florida Aquifer
system become depleted,
similar to the Ogallala?
What would happen if it did?
1. Turn in your hw (outline of pg 329-333) and your lab report
2. Bellwork: Pick a vocabulary word or case study from the board and define it
3. What’s your learning goal?4. Tonight’s HW: pg 333-340
October 26
Aqueducts
Effective at moving water from places that have water to place that need waterOlder aqueducts are open canals so can lose a large fraction of water throughleaks and evaporation (a problem in places like Israel and Jordan)
Wikimedia
Aqueducts
Newer aqueducts are commonly built as pipelines to reduce water loss, but they are still require a large amount of resources to construct and their construction can have negative impacts on the habitat during the construction process.
Catskill Aqueduct
New York Times
Construction of the Catskill Aqueduct
Colorado River Aqueduct
Wikipedia
The ugly Side of Diverting
Rivers
Aral Sea
Soviets diverted rivers that fed into the Aral Sea- Decreased the freshwater input
- Increased salinity- Killed the fish
- Reduced surface area dramatically- Dried up
- Caused dust storms (which has deposited salt on glaciers)
- Water is no longer there to moderate the climate so summers are hotter and winters are colder
…sigh
Saltwater to freshwater
Also called desalinization
Desalination
Can be accomplished through distillation, which boils water and then condenses the salt-free water vapor or through reverse osmosis, which pushes salt water against a membrane through which water can pass but salt cannot
California Water Wars
- Reading with questions and a practice FRQ - Neon markers on the black tables- Make sure each person writes an answer- When done, walk around and look at the
others answers- Revise your answer if needed- Make sure I’ve taken a picture of it before
you erase it!
October 27
1. Turn in your hw (outline of pg 333-341) 2. Bellwork: Reflecting on keeping a log of
your water use...How did your expectations differ from your results? How did your behavior change over the week in response to keeping a log?
3. What’s your learning goal?4. No homework tonight!
October 28
1. Turn in any late hw 2. Bellwork: Look at the class data. It’s pretty clear we all
use a lot of water. If we all were to cut down water use today by just 5 gallons, that’s a saving of 525 gallons per day. With that in mind, a. Write down the totals and averages on the
board.b. Write down a goal that you can achieve
that will save 5 gal/day. How will you do it?3. What’s your learning goal?4. HW - Read and outline pgs 531-535
Also, please consider watching Before the Flood, Sunday 9pm, on National Geographic
Our Water Footprint
Daily per capita use of fresh water
Our Water Footprint
1. Agriculture (irrigation, livestock)
2. Industrial (electricity, cooling machinery, refining metals and paper)
3. Household (indoor and outdoor)➢ Average American uses 157 gallons per day, whereas
the average Kenyan uses 11 gallons
How do we all increase
the supply of freshwater?
Change Personal Habits
Reuse and Recycle
3.5 gallons for a pound of paper
24 gallons to produce 1 pound of plastic
700 gallons to produce 1 cotton shirt
Reprocess Water
Construct dams & Reservoirs
BUT...Interferes with fish migration and natural rivers, displaces people, sediment buildup
Desalination
Costs a lot for not a lot of freshwater. And where do you dispose the brine?
Logicom Group
Drip Irrigation
Most efficient, but expensive
How does Drip Irrigation compare?
How does Drip Irrigation compare?
Easy and cheapFarmer digs furrows, fills with water65% effective
How does Drip Irrigation compare?
Flood the whole field, let it soak inDisruptive to plant growth, but 70-80% efficient
How does Drip Irrigation compare?
Giant sprinklersExpensive70-95% efficient
How does Drip Irrigation compare?
Uses slowly dripping hose95% effective
Hydroponic Agriculture
plants are immersed in nutrient rich solution, water can be reused, uses 95% less water)
Line irrigation channels
and cover canals
Prevents loss of irrigation water through seepage, but it’s expensive
Geomemmbrane
Plant crops that are less water
demanding
employ xeriscaping
Xeriscaping is a landscaping technique that uses less water, and is an alternative to regular lawn landscaping.
It means less urban runoff from lawn clippings and fertilisers, but are ugly to some and can be pricey
Meter Water Use + Pay More
It would force people to use less water, so municipalities would return on their investment in installation by having to pay less to water suppliers
Offer rebates for low flush
toilets and shower restrictors
People would be encouraged to use less, and water companies would get that money back by not having to pay as much to water suppliers
Reduce government subsidies
This would drive the price of water up and it would naturally be used less
...Use more groundwater?
But if rates of use exceeds rate of recharge, then subsidence, sinkholes, and saltwater intrusion could occur
Seed Clouds
It would increase precipitation in one area but water availability to other areas would be affected
Could we Engineer systems to
collect more runoff?
Well, maybe… but it’ll be high in pollutants
Neonspet River Water Association
Could we Use Icebergs??
Expensive and most would be lost before reaching final destination
Education
Inform people to make better decisions
Mark Dauberman
Rising Sea Levels
Why?
1) Water expands when it gets warmer
Why?
2) Melting of glaciers and ice caps
Positive feedback Loop
Decreases albedo (reflected sunlight), so more thermal energy is absorbed
Our future
Sea levels rose 6-8 inches in the 20th centuryPredicted to rise 7 inches in 2030 23 inches by 2090
Our future
Polar regions are getting warmer and at a faster rate due to their decreasing albedo
and the increasing carbon dioxide (which furthers the greenhouse effect, or the trapping of heat by atmospheric gases)
Why Care?
- 1 ft increase in sea level → 40% wetland destruction
- Erosion of beaches and bluffs- Saltwater intrusion- Inundation of seawater into low-lying areas- Increased flooding and storm damage
Why Care?
20% of the world’s population lives on the coast, and 50% within 120 miles. Those in Asia, Latin America, and the Caribbean are most affected
New York Times
