advantages of dams
TRANSCRIPT
-
8/10/2019 Advantages of Dams
1/17
-
8/10/2019 Advantages of Dams
2/17
What is a dam? A dam is an engineering structure built to block a valley
or other low lying area for the purpose of storing water
(Hancock and Skinner, 2000).
How many?
From 1992 there was over 10 thousand dams worldwide.About 500 dams are being creating every year, whichexceed 15metres in height. (Jiles and Spencer, 1995).
-
8/10/2019 Advantages of Dams
3/17
The main Advantages
Regulate water flow and Flood ControlSediment ControlDrought ControlTime for endangered species to be movedTo another suitable location.
IrrigationNavigation ImprovementGeneration of hydro-electric powerCan be made to suit geology, can be placed in narrow and
Wide valleys. In rock or soil types.
-
8/10/2019 Advantages of Dams
4/17
60% of total stream flow is regulated by dams andreservoirs for flood control (Jiles and Spencer, 1995).
This is due to flood peaks being reduced, and the
uniformity in base flow being increased throughout.
-
8/10/2019 Advantages of Dams
5/17
40% of rivers in Africa, Europe, North America were stabilized by dams.
Below is a map showing the Europe dams.
Map taken fromhttp//www.grid.unep.ch/product/publication/freshwater_Europe/images/eurodam.jpg
-
8/10/2019 Advantages of Dams
6/17
There is a reduction as the naturally erodingCliffs now have basal protection. (Less fluvialInputs).
Deposition location has changed, sedimentIs no longer built up in wetlands. Resulting in lessErosion in drainage basins.
-
8/10/2019 Advantages of Dams
7/17
Dams are needed in places of permanentDrought. To act as barriers to hold drinkingWater.
-
8/10/2019 Advantages of Dams
8/17
Looking at three Gorges Dam scheme in China.What were its advantages?
Prevent floodingHydro-power electricityIrrigation (agriculture)Domestic use
Navigation
http://www.digitalglobe.com/images/qb/three_gorges_dam_july13_2003_dg.jpg
-
8/10/2019 Advantages of Dams
9/17
Advantagesof the aswam dam:Prevent flood and drought catastrophic conditionsFor irrigation4000km2s of dessert can now be used by farmersFloodplain has been converted from 1 crop rotationto 3 crop rotation.Hydro-electricity.Countries income has increased by 500 million per year
Since it was built.
http://www.thirdworldcentre.org/aswpres
a.jpg
-
8/10/2019 Advantages of Dams
10/17
Endangered species can be removed and putInto a suitable habitat. This occurred with theSpecies Percina tanasi (Snail darter minnow).However the dam did not really affect thePopulation as they were found naturally occurring
In a near by stream. This was at the site ofTellico Dam on the Little Tennessee river inTennessee (Freeman, 1995).
http://bryonfreeman.com/v-web/gallery/albums/album15/res374114578.jpg
-
8/10/2019 Advantages of Dams
11/17
Transport on the River
Ferry transportation began in 1860s, they now use
barges
Economical
Consumer Benefits
Relieves rail congestionThe Pacific Northwest Barge Industry on the Columbia-Snake River
System by American Waterways Operation 1992-3
http://www.bluefish.org/pnbarge.htm
-
8/10/2019 Advantages of Dams
12/17
http://www.saveourdams.com
16 cents per bushel by
barge
32 cents per bushel
by rail (if
available)
92 cents per bushel
by truck
DAMS How important are they?
Provide waterfor transport
-
8/10/2019 Advantages of Dams
13/17
Provide Electricity for the communityRoll on Columbia By Beth Gibson http://members.aol.com/Gibson0817/river.htm
Columbia and Snake River supply 63% of hydro electric energy
Grand Coulee when built provided work after great depression
Brought cheap electricity to the area
Helped with the war effortLater Industry moved to Pacific west because of
cheap energy supply
http://www.deniskingphoto.com/coulee_dam/coulee_dam3.html
-
8/10/2019 Advantages of Dams
14/17
Ecology Friendly
96%-98% pass safely through turbines
Dams and turbines are not huge blenders
-
8/10/2019 Advantages of Dams
15/17
Ecology Friendly
H:\COLUMBIA RIVER BASIN - DAMS AND SALMON.htm
Fish Barges are a partial solution
-
8/10/2019 Advantages of Dams
16/17
A Commissioners Story
Les Wigen
Whitman County Commissioner
-
8/10/2019 Advantages of Dams
17/17
References
Anon, 1998 acessed at: http//www.grid.unep.ch/product/publication/freshwater_Europe/images/eurodam.jpg
Buchal James NG & 60 Min
http://www.saveourdams.com
Gibson Beth Roll on Columbia By http://members.aol.com/Gibson0817/river.htm
Hancock and Skinner, 2000, The oxford companion to the earth. Oxford University Press, Great ClarendonStreet, Oxford. Park, C., 1997, The environment, 29 West 35thStreet, New York. S Army Corps of Engineers, Northwestern Division POC: Adele Merchant, Pacific Salmon Coordination, (503)
808-3722 Page Updated: Thursday September 05 2002 H:\COLUMBIA RIVER BASIN - DAMS AND SALMON.htm http://www.deniskingphoto.com/coulee_dam/coulee_dam3.html The Pacific Northwest Barge Industry on the Columbia-Snake River System by American Waterways Operation 1992-3
http://www.bluefish.org/pnbarge.htm
Spencer, T., and Jules, H. 1995, Coastal Problems, Oxford University Press Inc, 198 Madison Avenue, New York.