Case Studies Flashcards
1
Q
Key features of the 3 gorges dam china
A
- a hydroelectric dam on the Yangtze River in china
- in terms of the amount of electricity it generates, it’s the worlds largest power station
- it cost $30 billion. However, it should only take 10 years to fully recover the costs
- the power generated by the 34 generators is enormous. It is equivalent to burning 25 million tons of crude oil or 50 million tons of coal
- over 100 towns and settlements were submerged when the dam was build. In addition over 1000 archeological and historic sites were also submerged and lost
2
Q
Key features of the south-north water transfer china
A
- the Chinese government is building a $62 billion south-north water transfer project
- this project would divert 44.8 billion cubic metres of water per year from the Yangtze River in southern china to the yellow river basin in arid northern china
- an estimated 330000 people were recently relocated for the expansion of the danjiangkou reservoir
3
Q
Benefits of the 3 gorges dam china
A
- power generation for the middle, eastern and souther china - industry and emerging middle class are ‘winner’
- controls water levels - will avoid frequent floods, which cause problems around the jinjiang river
- tourism - to see the Yangtze River where a calm lake makes scenic spots which were originally hard to enter are now reachable
4
Q
Drawbacks of the 3 gorges dam china
A
- residents - the dam partially or completely inundated 2 cities, 11 counties, 149 towns, 326 townships, and 1351 villages. About 23800 hectares, more than 1.1 million people must be resettled
- every year, about 265 million gallon of raw sewage are deposited in the Yangtze River. Sewage will collect in the reservoir, which increases the risk for waterborne diseases
- the dam is built near many geological fault lines. About 369 million people live within the watershed of the Yangtze River
- huge impacts environmentally - endangering 57 plant species, 25 fish species
- landslides may increase, one killed at least 30 people
5
Q
Benefits of the south-north water transfer china
A
- the project, officials say, saves china from a water Chris is that could set its development back years
- will distribute water fairly to the north of china
- vital for economic development and water supply to Beijing and other areas
6
Q
Drawbacks of the south-north water transfer china
A
- many are concerned that the project could exacerbate water pollution problems. Pollution from factories along the eastern route may render the water unfit to drink
- about 345,000 villagers have been displaced by the project to date. Many farming communities displaced
7
Q
What are the impacts of the California drought
A
Environmental
- about 1000 more wildfires than usual occurred
California is in the third year of one of the worst droughts in the past century
- prolonged drought threatens wildlife.
Economic
- last year, farmers harvested 640,000 fewer acres, but crops revenue remained strong
- farms have adapted more efficient water management technologies
Social
- water shortages and restrictions
- competition over water supply for agriculture, domestic use and aquatic ecosystems - could escalate to conflict over water use
8
Q
Causes of the California drought
A
- in normal winters, southwest winds from the ocean deliver water. Recently, for unexplained reasons, these winds have failed California
- tree ring studies: very little of the Californian drought can be attributed to climate change with any certainty
- cooler water temperatures - known as La Niñas - tend to produce drier conditions in the west. El Niño conditions would cause above average rainfall
9
Q
Previous droughts in America
A
- dust bowl (1930’s) - spanned 8 years in certain parts of the Great Plains. It was the worst American drought in the last 300 years, causing mass migration westward
- Great Plains drought (1950’s) - at its peak in 1954, it covered 62% of the country
10
Q
How did rainfall in Brazil change in 2014-2015
A
- usually, moist air from the south Atlantic encounters the Andes mountain range. This forces it southwards, creating a flow of moisture around the basin
- in 2014-2015, high pressure systems diverted moist air further north, causing heavy rains in Bolivia and Paraguay but dry air over brazil
11
Q
Impacts of the low rainfall in Brazil in 2014
A
- water rationing for 4 million people
- Brazil relies heavily on HEP for its power, so the drought caused power cuts
- increased groundwater abstraction ( in Brazil there are high fees to drill wells, this has kediri a vast number of illegal wells. In fact, 70% if wells are illegal, illegal wells are shallower and polluted
- the arabica coffee bean crop reduced, which drive global coffee prices up 50%
- by 2015, main reservoirs had reached 5% of there capacity
12
Q
Impacts of drought in the Amazon
A
- rainforests recycle 1/2 I’d their rainfall, so deforestation could trigger a positive feedback loop causing further drought
- a drying forest means reduced soil water storage and evapotranspiration. It also means that uncontrolled wildfires are much more likely to occur
- prolonged drought causes forest stress, which could lead the Amazon to a tipping point
- the Amazon intakes 20 billion tonnes of water vapour, which is mostly released over Brazil as rain
13
Q
Worldwide impacts of drought in the Amazon
A
- loss of a carbon sink
- wildfires
- changes to ENSO
14
Q
How is the pantanal (tropical wetland) valuable
A
- the pantanal is a significant freshwater ecosystem for birds and aquatic wildlife
- the river floodplain is vital and relies on seasonal rainfall
- when the seasonal rainfall come, 80% of the pantanal is flooded. The wetlands retain 60% all year round
15
Q
Impacts of the 2014 drought in Brazil on the pantanal
A
- the drought tested the reliance of the ecosystem
- there was an increase in tree mortality, which reduced habitats
- there have also been more wildfires, due to routine grass burning by cattle farmers igniting the dry firest
