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Paige Reisinger
Study Guide pg. 114-136
Nuclear Power Generation:
Advantages
It does not emit carbon dioxide and does
not contribute to global warming
The technology is readily available
A large amount of electrical energy is
generated in a single plant
It is very efficient, especially in
comparison to fossil fuels
Renewable Resources:
Advantages
They do not release pollutants such as
greenhouse gases or chemicals that
contribute to acid rain
They will not run out
They have a smaller ecological footprint
(the amount of land that is required to
absorb waste CO2 from fossil fuel)
Hydroelectric power:
Advantages
Turbines can be switched on whenever
energy is needed (reliable)
Dams are used to control water flow,
forming lakes, which can be used for
leisure purposes and irrigation as well as
electricity generation
Relatively cheap to run once construction
is complete
Disadvantages
The waste from nuclear power stations is
extremely dangerous and remains so for
thousands of years
The associated risks are high – power
plants are not 100% reliable
Ex) Chernobyl disaster
The energy source for nuclear energy is
uranium, which is scarce and nonrenewable
The time frame needed to plan and build a
new nuclear power plant20-30 years
Disadvantages
They are more expensive than fossil fuels
Not many technologies that can harness
renewable resources
Locations for renewable resources are often
limited by politics
Ex) “not in my backyard” with wind
turbines
Disadvantages
Flooding involving loss of habitat,
farmland and displacement of people
Dams restrict the flow of sediment,
affecting ecosystems or farming
downstream
Increased erosion rates downstream when
the flow of natural river systems are
disrupted
The cost of building dams is high, and
dams may eventually become unusable
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Tidal Power:
Advantages
Use of natural tide to turn turbines uses no
extra energy
Disadvantages
Installations are expensive to set up
May interfere with navigation and can
impact wildlife
Require good tidal range
Solar Energy:
Advantages
Cheaper for heating homes than fossil fuels
Disadvantages
It is expensive to turn solar energy into
high-quality energy
Limited in northern countries during the
winter months
Wind Power:
Advantages
They use the wind to turn the turbines,
which requires no extra energy
Disadvantages
If there is no wind, there is no energy
Biofuel:
Advantages
Less emissions
Disadvantages
It produces emissions and requires large
amounts of land to grow the biofuel crop
Biofuel crops may be planted where food
crops used to be, raising the price of food
Wastes:
Advantages
The resource is readily available and does
not reduce the natural capital
Disadvantages
Burning adds greenhouse gases to the
atmosphere
Geothermal Energy:
Advantages
Energy can be obtained from heat that is
already in the ground
No pollutants are released
Disadvantages
Pipes must be put into the ground, causing
the process to be expensive
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Case Study: Oil palm and habitat destruction
 Oil palm covers areas that were once covered by rainforest
 An oil palm plantation in Sumatra and Borneo have caused the destruction of 10
million hectares of rainforest
 Oil palm is now used for biofuel, increasing the demand
 This increased demand will cause the destruction of more ecosystems
Factors which affect the choice of energy generation
Sources of commercial energy for MEDCs
Sources of commercial energy for LEDCs
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Oil is used primarily for cars, which are more prevalent in MEDCs
LEDCs rely on biomass because it is cheap and accessible
MEDCs rely on gas or electricity in homes and businesses
Cultural and political factors contribute to the low usage of nuclear power
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Case Study: Narmada Dam, India
 Biomass is a large source of energy India
 The government is investing in hydroelectric power
 The Narmada Dam Project includes the construction of 3200 dams
 The Sardar Sarovar is the biggest and most controversial dam on the river
- 200,000 could be displaced
- Damage to the ecosystems of the region
- It will supply water to 30 million people
- Irrigate crops to feed 20 million people
- The dam is being built at the present
Soil Systems
Soil Composition:
-weathered bedrock, organic matter, air and water
Soil Horizons:
O organic horizon
A mixed mineral-organic horizon
E eluvial or leached horizon
B illuvial or deposited horizon
C bedrock or parent material
Soil-forming Process:
 Gains and losses of material to and from the profile
 Movement of water between horizons
 Chemical transformations within each horizon
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Soil Types:
Soil Productivity:
Sandy soil-low
Clay soil-quite low
Loam soil-high
Soil structure depends on:
-soil texture(amount of sand, silt, and clay
-dead organic matter
-earthworm activity
Shrinking limit- the state at which the soil passes from having a moist to a dry appearance
Plastic limit- occurs where each ped is surrounded by a film of water sufficient to act as a
lubricant
Liquid limit- occurs when there is sufficient water to reduce cohesion between the peds
Field capacity- the maximum amount of water that a particular soil can hold
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Soil Degradation
Causes:
 Water erosion
 Wind erosion
 Acidification
 Eutrophication
 Salt-affected soils
Climate change affects soils:
-higher temperatures cause higher decomposition rates
-more precipitation and flooding cause more water erosion
-more droughts cause more wind erosion
Human activity:
 removal of woodland
-roots binding the soil die and the soil is exposed to wind and water
 cultivation
-exposure of bare soil surface; large amounts of run-off
 grazing
-reduce the vegetation cover
 roads
-collect water
 mining
-exposure of bare soil
Soil Conservation Methods:
1. afforestation
2. terracing
3. cropping patterns
4. tree crops
5. contour plowing
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Case Study: Soil conservation of the Great Plains of the USA
 soil conservation methods were imposed by the Soil and Conservation Act of
1935
 nitrogen in soils was increased by:
-converting some areas to permanent grazing
-using ‘grass break’ to accumulate organic matter
 the introduction of herbicides has:
-made weed control possible
-reduced the risk of soil erosion
-reduced nitrogen loss
-increased salinity problems due to increased soil water evaporation
 no plowing methods have:
-reduced the soil salinity and annual weeds
-conserved more organic matter
 however, these methods have also:
-caused perennial weeds, which can be more difficult to control
-caused soil temperatures to be lower at the time of seeding
-caused fertilizer placement to be less easy
Case Study: Soil degradation at Tezipan watershed, Sierra de Santa Marta,
Veracruz, Mexico
 soil degradation is worsened when there is no fallow period
 maize and beans provide the country with a lot of food and cash
 farmers will not stop growing with bad methods because they need food and
money
Case Study: Subsistence farming – sustainable agroforestry
 in Santa Rosa, Mexico people are using the milpa system
 it is a diverse form of polyculture
 over 200 species are used
 there are three layers of plants, preventing erosion