water cycle Flashcards
shared water supplies conflict: Ethiopia and Egypt
Renaissance dam
90% of all countries share water basins with at least one geographical neighbor
Egypt depends on Nile for 90% of it water supply
158 of the world transboundary water basin lack any type of cooperative management
Egypt Ethiopia conflict: (Renisaunce dam)
1) 10 year period (to fill up reservoir) - Cut water supply by -14% - Destroy farmland by 18%
2) 7 year period (to fill up reservoir) - Cut water supply by -22% - Destroy farmland by 33%
3)5 year period (to fill up reservoir) - Cut water supply by -36% - Destroy farmland by 50%
dam 1800km long
project manager died all of a sudden- apparently took his own life
Rising demand for water and risk
california case study
State relies heavily on snow pack to resupply surface water stream and lakes- lack of winter storm led to decrease in snowpack. Relies on this for 30% of resupply
Aquifers are runnig low
lots for farming - fruit and veg
population doubled in 50 years - 20mn in 1970 to 40mn now
shortage of percipitation
high ocean tempratures creates condition for a high pressure ridge so dryness over California
60% of state in drought
less surface run off
The solution to California drought:
desalination
groundwater capture - which has 3x the capacity of overground reservoirs during heavy rains
groundwater management
reduce carbon output
2012-2016 - 6 year dorught
ENSO
ENSO cycles are the reversal of normal conditions in the ocean. Occurs every 3-7 years.
El Nino- is the trade wind patterns are disrupted so air circulation is reversed. This causes drought on the west coast of Australia and high rise flooding on the east coast of South America
La Nina- the normal conditions are exaggerated with stronger walker loop. This causes heavy rains in Australia but drought in South America. Sea levels can rise, e.g in Indonesia sea level rises by 1 m
Overabstraction of groundwater - Coca Cola
17 % of the world population in India but only 4 % of world freshwater so it faces water scarcity
510,000 liters of water drawn a day from boreholes - desertification of the local area
Water tables decreased from 12m to 35m below ground level.
3.8l of water needed to make 1l of coke
draining local aquifers- harvest dropped by 40%
little water left is undrinkable
drought in the Sahel
Physical:
occupies traditional climate zone
warm sea surface temperature
rainfall in the region is decreasing 3cm a month
water bodies are drying up
Human causes:
deforestation
higher birth rates
livestock numbers have increased by 40% since 1960
civil wars in neighboring countries lead to increased migration.
Impact of droughts:
decrease in vegetation cover so the soil is exposed to wind and rain.
evaporation from soil
increased risk of soil erosion
3 gorges dam - hard engineering to manage water
It reduced flooding downstream to major cities- 15mn people protected.
water in the reservoir of Dam is heavily polluted
decrease in silt and sediment downstream - this will cause increased river and coastal erosion - this will shrink wetlands - affecting the availability of freshwater
The Dam is the equivalent of 50 mn tonnes of coal a year for electricity produced - reduced pollution
affected local habitats- decline in the number of fish
1.4 mn people forcefully evicted - many who which received little to no compensation.
South north water transfer water - hard engineering to manage water
There is significant demand for water for economic growth up North of China where the land is arider and population density is higher.
water needed for irrigation for farmland up north
water tables in Bejing if falling at a rate of 5m per year - due to abstraction of groundwater
total of 44.8 bn cubic meters of water transfer
cost $100bn
environmental issues, resettlement issues ( forced eviction), resettlement issues
Sustainable management: Israel
Israel has a poor climate and geographical situation for adequate water supplies
Deal sustainably:
Strict conservation techniques
Charge real value price for water
Recycling sewage - water used for 65% of crops in agriculture
Use smart irrigation
Importing food with high virtual water - save on agriculture water needs
DESALINATION
advantages:
Prevent drought
Reduced depletion of aquifers
Saving to economy $155mn
Ability to sell water and reduce conflict over water
The cost of desalination plants dropped significantly
40% of the water comes from desalination
Disadvantages:
Releasing by-product of desalination into oceans (salty) - impact still unknown
Cost of water 60 cents per cubic meter
Can cause heart problems amongst locals due to mineral composition of the water.
Sustainable management: Singapore 4 taps
Holistic management
5.4 mn people of Singapore are water metered - reduce water wastage.
Cutting water leaks to 5% - this is extremely low.
Water prices rise and fall based on usage.
rainwater collection.
Subsides water for the poor.
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Tap 1 - imported water:
A bilateral agreement with Malaysia 1960.
40% of water needs come from Johor pipeline from treatment
plant next to Johor plant. Extract 205 mn gallons a day
Tap 2- catchment water:
little groundwater in Singapore
No natural lakes or rivers more than 10km
Collection of rainwater
17 reservoirs - reduce runoff
effective flood prevention method
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Tap 3 (NeWater)
Reuse water endlessly.
Sewage from homes and industry is collected and treated to 1 of
5 treatment plants.
Water is filtered and resupplied to the non-domestic sector.
There are plans to combine sludge with municipal waste.
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Tap 4 (desalination)
2 desalination plants provide 25 % of the country’s freshwater needs
It is expensive - 3x more expensive than importing water
Use lots of electricity
But it is climate-proof
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Singapore’s approach shows how they are not dependent on one factor for their water supply (unlike Egypt) so can sustainably manage the supply of freshwater and prevent water stress.
Water sharing treaties and framworks:
water war is considerable and to prevent this cooperation is needed. TNC, govt, and NGO all have a role to play.
Integrated river basin management:
- all-inclusive of all sectors - open conversations
- effective pricing of water
-effective local governance linked to national strategies
- freedom from corruption
Treaties and Frameworks:
-India and Pakistan, Indus valley Treaty - being honored despite other issues
- Nile basin
-Helsinki rules (1966)
-UNECE water conservation (conservation of freshwater ecosystem in Europe)
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Water sharing treaties and framworks
Case studies:
1) Berlin rules of water resources:
-outline international law relating to freshwater resources (within or transboundary resources)
- 9 water management principles
Participatory water management, coordinated use, integrated management, sustainability, minimization of environmental harm, cooperation over shared resources, avoidance of transboundary harm, equitable utilization, equitable participation.
The ongoing conflict in the Nile shows how hard it is actually to implement such treaties.
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2) Colorado integrated river management:
- 2330km long Colorado river - huge demand for water.
- basin divided up by states and water allocated, plan to cover HEP production, river regulation ext
- but some states used up their allocation quickly and water was running low in the river - not enough to meet demand.
-growing cities such as Las Vegas and states like California needed more water so the growing demand
- as a result no new agreement has been reached
