EQ3 5.9 MANAGING WATER Flashcards
what is water transfer
Water transfer is one example of a large-scale hard engineering scheme that tries to provide a techno-fix to water disparity.
what is the aim of the South-North water transfer: China
China’s South-North Water Transfer Project aims to deliver 25 billion m3 of freshwater per year to the drier north by two routes (central and Eastern). A third western route is currently being planned.
why is the South-North water transfer: China taking place
As 2/3rd of the farmland are in the North and 80% of the water is in the south, this provides a perfect opportunity to distribute the water to ensure agriculture and water security for the nation.
what are the economic cons of the South-North water transfer: China
The Water Transfer is expensive - estimating to cost around US$80billion in 2015. This is before maintenance costs and water prices are considered.
It is likely to be too expensive for the farmers, resulting in them continuing to use groundwater despite the scheme.
what are the social cons of the South-North water transfer: China
Over 300,000 people have been displaced for the construction of the Water Transfer’s central route.
what are the environmental cons of the South-North water transfer: China
Transferring water via Water Transfer does not address the main causes of water shortages in the North. The North has a limited water supply because of the pollution of water sources, water inefficient agriculture and poorly managed use for industry.
By removing water from the Yangtze it may further reduce discharge levels. The impacts for the river ecosystems will be devastating, in addition to those already caused by the Three Gorges Dam.
what is a mega dam
Mega dams (e.g. the Three Gorges Dam) are a hard engineering scheme that cost a significant amount of money and have controversial socio-economic and environmental effects.
what are the economic cons of the three gorges dam
632km2of land was flooded, including 1,500 villages and towns to form the reservoir behind the dam.
what are the social cons of the three gorges dam
1.3 million Chinese residents were relocated and the local history from those villages was lost.
what are the environmental cons of the three gorges dam
Water quality is poor because of the surface runoff allowing industrial waste, sewage and agricultural chemical runoff to enter into the Yangtze further upstream.
Ecosystems were flooded and destroyed, leaving animals without a habitat. Vegetation decay led to the release of methane.
pros of the three gorges dam
The Three Gorges Dam is designed to control flooding on the River Yangtze and improve the supply of water by regulating the flow.
The Dam would also benefit locals by providing HEP energy and making the river navigable. This was crucial for the economic development in China to reduce its reliance on fossil fuels, in particular, coal.
The water held back by the Dam can also contribute to the water being transferred by the South-North Water Transfer.
desalination plants
Desalination plants provide an effective way of removing the salt from seawater to produce clean safe drinking water. The process is both financially expensive and energy extensive.
desalination plants in Israel
The source of salt water for Israel’s desalination plants is the Mediterranean Sea.
By 2013, Israel had five fully functioning desalination plants.
By 2020, Israel aims to supply 70% of its domestic water supplies from desalination plants.
pros of desalination plants
Desalination plants provide a supply of water that is both reliable and predictable.
The desalination plants are able to produce up to 600 tonnes of clean drinking water an hour.
cons of desalination plants
Desalination plants are so energy exhaustive that each plant needs its own power station.
The by-product of the salt water is brine (a very salty liquid), which can be extremely damaging to the environment.
what is smart irrigation
Smart irrigation is a sustainable method that provides crops with below optimum water levels during the growth stage so they become less sensitive to the lack of water, consequently saving water
smart irrigation
Smart irrigation is a sustainable technique that provides crops with below the optimum water levels during the growth stage so they become less sensitive to the lack of water. The crops produce the same quality and quantity produce whilst using less water.
An example of a way that water is regulated and restricted is through drip-feeding. Through this method, the water goes directly into the soil next to the roots of the crops, preventing waste and loss of water via evaporation.
australia smart irrigation
In Australia, the use of smart irrigation for fruit trees has resulted in a 60% increase in water productivity.
An improvement has been seen in fruit quality and also in retaining the yield size by using the smart irrigation technique.
water recycling Singapore
Singapore is a city-state with a population of 5.4 million on only 710km2 of land.
The city receives abundant rainfall with 2,400mm of precipitation a year but there is limited land availability for collection and storage of rainfall.
The high temperatures in Singapore mean high evaporation rates and also a lack of groundwater resources despite the high levels of precipitation.
water recycling techniques in Singapore
Singapore’s water agency has invested in several ways to ensure its water security:
Local rainwater is collected via drains, canals and storm-water collection points before being treated to become drinking water.
The NEWater scheme treats and purifies used water producing high-grade recycled water. There are four NEWater plants meeting 30% of the countries needs- but there are plans to raise it to 55% by 2060.
Singapore has signed an agreement until 2061 to import water from Malaysia.
Desalinisation plants.
what are sand dams
In the Machakos District of Kenya, the hot and dry climate stops the river flow in the dry season so rural communities struggle to store water. Sand dams improve the reliability of their water supply.
sand dams during the rainy season
During the rainy season
When the river is flowing, sand is trapped behind the 1m high dam.
Water gets trapped in amongst the coarse sand particles.
sand dams during the dry season
The sand stops the water from evaporating when it gets hot.
Locals can extract the trapped water by:
Digging wells.
Channelling the water through the dam and tapping it off on the other side.
Digging holes.
advantages of sand dams
The sand dams are cheap to construct.
Local materials are used to build the sand dams.
The sand dams require very little maintenance.
Dam height can be increased each year so that more sand and more water are trapped by it.
The water recharges the whole area leading to an increase in vegetation surrounding the dam.
Locals are trained by water charities to make the dams so that they can be self-sufficient going forwards.
