Three Gourges Dam Flashcards
Hard engineering
Involves the use of technology to create permanent features to control rivers
Soft engineering
Tried to manage a river by working with its natural system
Location
Asia,China
On the Yangtze river
Upstream (west) from the Yellow Sea
Mouth near Shanhai
Fact file
Largest hydroelectric power station in the world
2.3km across, 181m high
A total of 12 cities, 140 towns, 4500 villages, 4000 hospitals and clinics, 40,000 tombs, 1300 archeological sites have been submurged
Total cost of £25.5 billion
Building time: started 1994 and reservoir reached its full height in 2010
Purpose
To control the flow of the river, locks have been built inside the dam
These can be opened varying distances in accordance with the ever of water in the Yangtze river
E.g. if the water level was higher in spring because of heavy rain, the locks could be adjusted to be more closed
This helped to prevent flooding further downstream
Economic advantages
Huge ships can transport good further upstream.
Produce can now be sold in wider areas
Economic disadvantages
Dam now stops most of silt that was being carried downstream.
50% of the 500 million tonnes of silt will be deposited behind the dam.
Therefore very expensive maintenance.
Social advantages
Prevented flooding downstream where 100 million have been affected on a daily basis.
Reduced flooding from a 1 - in -10 year event to a 1 - in - 100 year event.
HEP station provides 11% of China’s electricity.
Social disadvantages
Many cities, towns, archaeological sites and hospitals have been submerged.
At least 1.4 million forced to evacuate.
Another 100,000 might be moved due to dangers of landslides and bank collapses.
Were promised compensation (which included new homes and jobs). Many have not yet recieved this.
Environmental advantages
Species downstream of dam now protected from flooding.
Environmental disadvantages
Concerns about quality of water because more rubbish is being stuck behind the dam as it is no longer able to travel downstream.
Therefore river dolphins and the Yangtze sturgeon are in danger of becoming extinct.
Rising water levels mean that land around the River is becoming destabilized and landslides have become more frequent.