Managing water supplies using hard engineering
- Created by: ZoeCouch
- Created on: 23-01-18 09:17
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- Managing water supplies using hard engineering
- Dams (example: Three Gorges Dam in China)
- Outline and Aims
- The building of a dam across the River Yangtze
- subsequent creation of reservoir upstream (large store of water)
- To generate HEP
- river regulation to improve supply and control flooding on Yangtze
- build up surplus of water to be diverted to northern china
- Benefits
- Electricity generated is vital for China's growth
- reduced water shortage risk in Bejing due to diversion of surplus water
- Has reduced water shortage close to the Yangtze improving supply.
- Dams provide a huge addition to blue water component by storing 15% global runoff- more accessible for China
- Costs
- 632km² of land has been flooded to form reservoir
- 1.3million people have been relocated from 1500 villages and towns
- Reservoir water quality is low due to industrial, agricultural and sewage waste entering from upstream
- Decomposing vegetation in the reservoir produces methane, released when water passed through HEP turbines- increasing Greenhouse Gas effect
- expensive
- Now Yangtze is navigable for cruise ships and trade ships
- Effective?
- The Dam was effective at reducing major downstream flooding from once every 10 years to once every 100 years
- The dam has increased availability reducing economic water scarcity in sme areas
- water surplus diversion allows dam to provide not just for local area but for areas further north such as Bejing which have reduced resources.
- Pollution of water reduces water quality and means there is less good quality water per capita than if other methods such as desalination had been used for management.
- Outline and Aims
- Desalination (example: Israel)
- Outline and Aims
- By piping seawater from the Mediterranean and Red Sea to new inland desalination plants, (five opened in 2013), the aim is to provide 70% of Israels domestic water supply by 2020
- Costs
- dumping desalinated water (high in salt concentration) near shoreline will have adverse effects on coral reefs and their food webs
- the main costs are environmental with major ecological impact on marine life
- Each plant requires its own power station and adds to C02 emissions though much of energy used is solar
- produces vast amount of brine which harm ecosystems
- Benefits
- less energy intensive and easier to implement on a larger scale
- produces up to 600 tonnes of potable water per hour
- sustainable process as it uses saltwater not freshwater, so conserves water for suture generations
- more recent discoveries in technology are reducing cost of desalination which is far more cost effective than using increasingly expensive freshwater resources
- Effective?
- reduces water shortages overall and provides much water for Israel which can then be evenly distributed at a cost effective price.
- effective management through conservation of freshwater supplies
- desalination is reliable and predictable
- Outline and Aims
- North-South Transfer Project in China
- Outline and Aims
- Three routes will take water from Yangtze river to northern China: a Western route to the Yellow river, an Eastern route via a series of lakes and a Central route.
- To reduce risk of water shortages in Bejing and boost economic development.
- Bejing needs water as despite home to 35% of China's population and with 40% arable land, it recieves only 7% of water
- due for completion by 2050
- Benefits
- reduce abstraction of groundwater
- reduce water shortages caused by drought in the North
- Increased food supply from further irrigation in the north
- reduces physical water scarcity in Bejing
- Costs
- It will submerge 370km² of land
- May increase water shortage risk in south if too much is drained
- Yangtze river already polluted and water of yellow river considered undrinkable
- damage to fish stocks, spreading disease and pollution and well as acting a a pathway to introduce alien species into new river environments
- potential increase for flood risk
- East route is industrial and risks further pollution
- Effective?
- The transfer project is effective when considering the reduced water shortages in north China and more equal distribution
- The potential for pollution decreasing availability of good quality water is not effective as a management strategy however
- The fact that water distribution could potentially sway in the opposite direction with the south recieving less water is not effective management
- Outline and Aims
- Dams (example: Three Gorges Dam in China)
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