Hard engineering strategies to reduce water supply- Geog, Water unit, EQ3

what can hard engineering strategies also be known as?

techno-fixes

what do hard engineering/techno-fixes involve?

capital-intensive, large scale construction projects

to increase water supply to meet rising demands

(often:signif ,complex,advanced tech)

while they can create s________ b______, they also can create l__-term e____, s_____ and e_________ challenges

substantial benefits

long term

economic,social and environmental

the 3 case studies of techno-fixes we learn?

china south-north water transfer scheme- Water transfer projects

Three gorges dam (china)-Mega dams

israel’s desalination- Desalination

overview of china’s south-north water transfer project

eg: cost, routes, amount of water moved per year, how it is moved, where water is diverted

• diverting water from the areas of surplus in the south to areas of deficit in the north—> water in china is unevenly distributed

• uses canals, tunnels and pipelines

• the largest transfer project in the world

• moves 44.8 billion m³ of water annually

• 3 diff routes (eg eastern- highly polluted)

• cost over $70 billion

why china needs the transfer project:

what % of freshwater resources does the south have?

80%

whilst the north has chronic shortages (incl: beijing and shanghai)

advantages of the china snwtp?

• transports over 44.8 bill m³ annually which benefits the industrial north a lot

• creates water for irrigation and agriculture in the north

• supports over 200 million people in cities

• supports economic griwth in the north

•  supports health in the north as more safer/potable water

• means beijing can stop overabstracting groundwater→ groundwater levels are increasingly 0.5m per year

disadvantages of china’s snwtp?

• high evaportaion rates as majority of water is transported by open canals

• over 330,000 people have been displaced

• cost over $79 billion—> high pressure on tax payers and the economy

• eastern route is highly polluted as it passes through many industrial centres/ cities—> often the water is so polluted and contaminated that it is barely usable even after treatment

• only 27% of northern china’s water supply comes from the transfer project, 45% still comes from groundwater supplies still

• the south is increasingly experiencing deficits as a lot of water is taken and transported—> impacts the farmers and environment

• the project crosses 5 earthquake faults SO if one occurs, the three gorges mega dam will fail as well as the extensive infrastructurthat makes up the transfer project and millions of homes and there will be high flooding

overall, is the china snwtp positive or negative for china?

In theory= positive, logical as increases the supply for areas of deficit and prevents over abstraction

in reality= negligible of the social impacts in the south and the economic cost is major (but china’s huge economy can handle this), and high evap and high pollution= counterproductive

overview of the Three Gorges Dam (mega dam eg)

• in china

• on the yangtze river

• the world’s largest hydropower project

• storage capacity= 39.3 billion m³

• very controversial

advantages of the three gorges dam in china

• produces over 22,500 MW of electricity through HEP- helps supply 10% of the population—> reduces reliance on coal

• supports irrigation which increases agricultural productivity

• has a high storage capacity/ stores vast volumes of water- over 39.3 billion m³ of water

• good for domestic use

• helps control seasonal flooding downstream→ protects citie like Wuhan, in total protecting over 10 million people

disadvantages of the three gorges dam in china?

• cost= $22.5 billion—> huge economic cost and pressure on the econ and taxpayers

• displaced over 1.3 million people from over 1500 villages

• over 632 km² of land has been flooded to create a reservoir—> environmental toll AND water here is contaminated by industry and sewage and farms

• huge ecological damage—> changes to the river’s ecology has meant the Chinese river dolphin is now extinct and other species are also threatened

  • over 250 million tonnes of silt is trapped behind the dam every year—> reduces sed downstream as it is trapped which degrades farmland and the delta ecosystems

what is desalinisation?

removing salt and other minerals from sea water to produce potable water

common methods:

• reverse osmosis

• multi-stage flash distillation

why does israel need/use desalination?

it faces extreme water scarcity as semi-arid climate and high pop density

reliant on the river jordan and aquifers

how many large-scale desalinisation plants does israel have?

how much of domestic water do these supply?

5

70% of dpmestic water (as of 2022)

israel is part of MENA- what is this?

middle eastern and north american (countries)

advantages of desalinisation in israel?

• reduces pressure on river jordan and mountain aquifers and the Coastal aquifer where there is high over-abstraction

• produces over 600 tonnes of potable water per hour

• supports agriculture and maintains water-extensive exports (a large producer or fruits and flowers)

• has reduced cost of water—> by 2016 $2= the cost per m³ for households

• it has allowed the Sea of Galilee to recover —> water levels have increased over 2 m since it began to be used

disadvantages of desalinisation in israel?

• the gov has invested over $2 billion on desalinisation since 2002

• VERY energy intensive—> takes around 2 KWh of energy to prod 1m³ of freshwater( mostly produced through bburning fossil fuels and using nuclear plants which increases CO2) BUT does use solar energy

hard engineering can help c____ and i______ thrive in a___ climates

cities and industries

arid

BUT hard engineering can create n__ v_________

new vulnerabilities