Water Cycle case studies Flashcards
Mega dam
Three gorges dam in China
Hydroelectric power on Yangtze River, worlds largest power station
100 towns submerged when the dam was built
The emerging industry are winners due to power generation
It controls water levels in Jinjiang river
Water transfer project
South- North water transfer project in China
$62 billion cost
Diverts 44.8 cubic meters per year from Yangtze River to Yellow river basin in northern China
330K people had to be relocated for expansion of reservoir
Deforestation in Amazonia
Humans disrupt drainage basin cycle
20% forest destroyed
Removes sinks and stores
Increased soil erosion
Decreased interception and percolation
Water conflicts
River Tigris and Euphrates
River supplies Syria and Iraq but its source is in Turkey
Reduced water flows 80% and 40% in Iraq and Syria
Syria built dams so less water reached Iraq: allowed salt water encroachment and decreased agricultural yield in Iraq
Intergovernmental panel on climate change (IPCC) predicts permanent decrease in rainfall so more conflicts as Iraq has less water
The deal was that Turkey would maintain 500 cubic meters a second in 1987
Bolivian water war 2000
Contracted Aguas del Tunari to administer water provision in Cochabamba - increasing water rates and irrigation networks for farming communities- so they charged new customers and paid for themselves
Barricades, rallies so government dispatched soldiers using weapons
Protesters grew so government collapsed and reversed privation
Defining water insecurity
Water stress- between 1000 and 1700 cubic metres per capita
Restriction on water use
Renewable water sources- internal= recharge of aquifers, discharge os rivers, external= generated outside the country
Water scarcity= 500-1000 , unsatisfied demand, competition
Absolute water scarcity- less than 500, widespread restrictions
Water poverty in Karachi, Pakistan
Queues for 7 hours at water board office- first come first served
20 million population most have no running water
Criminal gangs selling water on black market = extracting from pipelines
Richer drink bottled water and use it for swimming pools
Contrasting river basins
Amazon- uniform, discharge high all year round, low flow Nov = below 100,000 cumecs
Yukon- seasonal, distinct periods, low flow in winter= below 1000 cumecs
America
Murray Darling- seasonal, low builds to Hugh discharge, lowest flow below 100 cumecs in January
Australia
Tropical, temperate, polar water budgets
Tropical
- Medium to high precipitation
- medium to high evapotranspiration
- little or loads surface run-off and base flow run-off
Temperate
- Medium precipitation
- medium evapotranspiration
- medium surface run-off and base flow run-off
Polar
- little precipitation
- high evapotranspiration
- loads surface run-off and base flow run-off
Human activity contributes to drought risk- Sahel
Sahelian
- Regular basis since the early 1980s.
- The area experiences wet and dry seasons
- Human activities such as overgrazing, overcultivation and the collection of firewood can lead to desertification, particularly when combined with drought conditions.
- The result is crop failure, soil erosion, famine and hunger
Human activity contributes to drought risk- Australia
30% affected by severe rainfall deficiency
Big Dry of 2006- associated with longer term climate change
Unlike Sahel not followed spiral of desertification
large-scale recycling of grey water
constructing desalination plants
devising new water conservation strategies.
UK floods 2007 (8)
Wettest summer since records began- 414mm of rainfall across England and Wales from May to July
In late July, Gloucestershire and Worcestershire flooding, left 48,000 homes without power for two days
The RAF and Army were called in to help when Tewkesbury became cut off
Surface water and river flooding affected more than 55k homes and businesses across the country
7k rescued
17k families had to leave their homes
13 died
total losses at about £4bn
Nile River Basin- key facts
4,132 miles, shared by 11 African countries (eg Sudan, Egypt, Uganda)
What are the water rights in the Nile River Basin? (integrated basin management)
Nile Water Agreement granted Egypt most water (apart from bit in Sudan)- upper course people forbidden to use
1959- Egypt and Sudan signed agreement to allocate more equally but Egypt depends for 90% of needs
Egypt’s military power in other countries ensured no interference with water due to busy defending
1990- cooperation needed
so by 2006 a Nile River Basin Commission established to ensure equal and fair usage of the River Nile
Dams in the Nile- Transboundary-water source conflict (6)
Egypt, Sudan, and Ethiopia depend on inflow from the Blue Nile
Great Ethiopian Renaissance Dam project – a dam built at $5bn
largest hydropower project in Africa
creates reservoir containing 74 billion cubic meters of water
Ethiopian government announced plans to fill the dam so Egypt and Sudan held a joint war exercise called “Guardians of the Nile”
The filling would reduce water supplies to downstream Egypt by over 1/3 and reduce agricultural land in Egypt by 72%
Egyptian agriculture could lose $51 billion
GDP loss= unemployment displace people and disrupt other economies
Sustainable schemes of restoration (2)
Singapore
A smart irrigation controller or timer has built-in water saving features eg a sensor to adjust to the optimal sprinkler run time based on the local weather condition
Recycling water
30% of Singapore’s water supply is currently met by recycled grey water
Integrated drainage basin management- Colorado background (4)
Colorado River 233 km long 97% flows through USA and rest through Mexico
Levels of precipitation vary- starts in the Rocky Mountains and through semi-arid areas to the Gulf of California in Mexico
Increase in population, urbanisation and agricultural demands= pressure as a water source
Climate change= lower precipitation areas of drought across River basin=further pressure
Integrated drainage basin management- Colorado River Storage Project (5)
1956- Colorado River Storage Project for regulation between the states, irrigation development and HEP production
Now 29 dams along the course of the river
Despite the project providing HEP, flood control and water storage- been no methods that can sustainably remove all the water needed from the Colorado River
Individual states are looking for alternative solutions and sources.
eg Nevada is negotiating for extra water allocation (particularly for Las Vegas
Solutions have not been met.
