Damns by Sarah and Allen
JUST KIDDING WE KNOW HOW TO SPELL DAM
How
 Disadvantages
 Case studies
By Clip Art
Why do we build dams?
From: http://www.waterencyclopedia.com/images/wsci_01_img0129.jpg
 Dams can store rain water or water directly from the river itself.
Then, in case of a Drought, the dam will still have a relatively
constant supply of water.
 Producing Power.
 Controls flooding & provides recreational activities such as boating
fishing and swimming, if the lake is not being used for drinking
water (Dam Society).
 Simple design makes for inexpensive repairs and maintenance
costs (Dam Society).
Advantages of Building a Damn
From: http://www.waterencyclopedia.com/images/wsci_01_img0129.jpg
 Simple design makes for inexpensive repairs and
maintenance costs (Dam Society).
 Produce inexpensive (after completion) and clean power.
 Renewable energy source, because the water is not
destroyed by passing through the dam.
 If needed, dams can be shut down instantly, where thermal
plants take hours, and nuclear plants can take days! (Dam
Society).
 Very few breakdowns.
River diversion and the Aral sea
 Aral Sea in Central Asia.
 Evaporation matched by inflows of water from the Amu
Darya and Syr Darya rivers.
 1960 building of dams
 eliminated the flow of water into the sea
MORE INFO
From:
http://landsat.gsfc.nasa.gov/graphics/img/f00
12.jpg
From:
http://landsat.gsfc.nasa.gov/graphics/img/f00
12.jpg
River diversion and the Aral sea
 1995, the area of the Aral Sea was only 30,000 square kilometers,
 1960 64,500 square kilometers.
 fishing industry which once supported 60,000 workers  halt
 20 of the 24 fish species once caught in the sea have been extinct
 bird species found in the Amu Darya Delta had declined from 319 to
168,
 the delta forests had died
 only 30 out of 70 species of mammals remained.
From :http://malaysiafishingtour.com/wp-content/uploads/2010/11/Fresh-Water-Fish.jpg
Sediments & Erosion
From:
http://www.ape
rfectworld.org/
clipart/Nature/ri
ver02.GIF
Sediments & Erosion
From:
http://www.ape
rfectworld.org/
clipart/Nature/ri
ver02.GIF
•
•
•
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velocity of the water drops
Sediment carried by the river dropped
erosive potential of the river is increased
sediment deprivation affects shoreline processes
and biological productivity of coastal regions.
Grand Canyon
 Grand Canyon below Glen Canyon Dam –1963
 Erosion of the sediment along the beaches began because of
the lack of incoming sediment.
 Beaches disappeared!!
 1996 project  recovered beaches but was short-lived
Want to know more?
From:
http://www.ape
rfectworld.org/
clipart/Nature/ri
ver02.GIF
From:http://1.bp.blogspot.com/_gbzApcV7MwY/SNE64u2XpgI/AAAAAAAAAQI/jCxvHTL0jAI/s400/nemo_4.jpg
Columbia River
 averaged between 10 and 16 million fish before non-native
settlers first arrived in the 19th century.
 130 or so dams in the basin,
 1.5 million salmon and steelhead enter the Columbia each
year
Thirsty for more knowledge??!!
Works cited
 " Dams - Impact Of Dams - Water, River, Flow, Sediment, Colorado, and Lake ."
Science Encyclopedia. N.p., n.d. Web. 14 Apr. 2011.
<http://science.jrank.org/pages/1942/Dams-Impact-dams.html>.
 "Dams and Migratory Fish | International Rivers." International Rivers. N.p., n.d.
Web. 14 Apr. 2011. <http://www.internationalrivers.org/en/node/1639>.
 "Hydrological Effects of Dams | International Rivers." International Rivers. N.p.,
n.d. Web. 14 Apr. 2011. <http://www.internationalrivers.org/node/1640>.
 "Hydrology | Carl Renshaw." Dartmouth College. N.p., n.d. Web. 14 Apr. 2011.
<http://www.dartmouth.edu/~renshaw/untitled_text/hydrology.html>.
 "PROS AND CONS." Sir Francis Drake High School Website. N.p., n.d. Web. 14
Apr. 2011.
<http://drake.marin.k12.ca.us/stuwork/rockwater/Upload%20this%20doc-dams%20and%20hydropower%20report/pros%20and%20cons.html>