Case Studies Flashcards
Key features of the 3 gorges dam china
- 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
Key features of the south-north water transfer china
- 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
Benefits of the 3 gorges dam china
- 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
Drawbacks of the 3 gorges dam china
- 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
Benefits of the south-north water transfer china
- 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
Drawbacks of the south-north water transfer china
- 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
What are the impacts of the California drought
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
Causes of the California drought
- 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
Previous droughts in America
- 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
How did rainfall in Brazil change in 2014-2015
- 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
Impacts of the low rainfall in Brazil in 2014
- 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
Impacts of drought in the Amazon
- 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
Worldwide impacts of drought in the Amazon
- loss of a carbon sink
- wildfires
- changes to ENSO
How is the pantanal (tropical wetland) valuable
- 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
Impacts of the 2014 drought in Brazil on the pantanal
- 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
What are the players in the river Tigris and Euphrates
- these two rivers supply Syria and Iraq, however the source is turkey
- turkey has been building hydroelectric dams (reduced water flows into iraq and syria by approximately 80% And 40% respectively)
- syria built dams in response, which lead to even less water reaching iraq. Thus almost lead to war in 1975
- low flow rates in iraq have allowed salt water to infiltrate nearly 150km inland (saltwater encroachment) from the Persian gulf (the decline in water flows has a,so led to decreasing agricultural yields. Iraq reported its worst creak harvest in a decade in 2009, indicating a potential food security problem)
- in 2018, iraq threatened to take its case for an increase in water flows from turkey and Syria to the UN
Use of water as political leverage in turkey and Syria
In 1987 turkey and Syria came to an agreement over water sharing
- turkey would maintain a flow rate if 500 cubic metres a second where the Euphrates river passes into Syria
- turkey asked for syrias cooperation on the issue of the Kurdish rebels residing in Syrian territory
- this has created a dangerous precedent, as water scarcity is set to increase, and political leverage wielded by turkey will consequently increase in turn
He future of water security for Iraq
- several droughts in Iraq in recent .years has increased the likelihood of conflict in the future. The risk of regular future water shortages could make the Iraqi peoples increasing desperate
- projections by the intergovernmental panel on climate change indicate a changing climate and the potential for a permanent decrease in rainfall, additionally, rapid increasing populations within the region could escalate tensions into major conflict in the future
What happened in Pakistan in 2010
One of the world floods in Pakistans history occurred, the water levels in the river indus which runs the length of the country were said to be the highest in 110 years. 1/9 of pakistans 190million people were affected. The recovery was expected to take several years
Cause of the Pakistan floods in 2010
- at the end of July 2010 the north west province of khyber pakhtunkwa (KPK) was hit by a 5 days period of exceptional precipitation, including 60 hours of continuous rainfall. This exceeded the total amount for monsoon season in this region by 30%
- after this surge the monsoon rains continued as normal to add to the rivers discharge.
- more heavy storms in the birth west and far north east provinces caused 2 further waves of flooding.
- at the gates of the one mile wide Sukkur barrage, river flow peaked at at 32,000 cubic metres a second
How were the effects of the Pakistan floods in 2010 increased
- the swat valley in KPK had widespread deforestation while under the control of the taliban
-construction of levees raised the river channel above the surrounding plains - releases to river banks were prevented by heavy monsoon rains and waves of flooding
- a rare meteorological pattern in the summer of 2010 allowed storms to spread into Pakistan
- climate change led to an increase in the occurrence of warm temperatures and increased number in heavy rainfall events
Environmental impacts of the Pakistan floods in 2010
- 1/5 of Pakistan was submerged
- 10,000 villages indundated
- 1.2 million houses damaged
- 7 million ha of the most fertile arable land was obliterated
- tripling of food prices
- by the end of august the cost to agriculture was £1.5 billion.
- bridges and roads washed away
Human impacts of the Pakistan floods 2010
- 1600 deaths
- 14 million people affected (6 million children and 3 million women of child bearing age)
- 6 million at risk from starvation
- 300,000 refugees in the city of sukkur
Pakistani aid efforts after the 2010 floods
Army aid
- 30,000 people were rescued by helicopters and boats within 72 hours
- 30,000 soldiers involved: delivering food, rebuilding bridges, setting up camps for refugees
- within the first week the army rescued 100,000 people
Government
- president asif Ali Zardarin was condemned for taking a trip to Europe shortly after
- after a week of flooding the government had still failed to provide any emergency supplies: no food, water , tents, blankets, medicine.
- funds for aid were short: 5% of Pakistanis pay tax the Pakistani relief fund only raised £900,000
- hundreds of thousands of soldiers were involved in fighting the taliban so could not help with flood relief
