Hard Engineering

Question 1

What are the four types of hard engineering?

Answer 1

• Embankments (levees)
• Flood Relief Channels
• Dams and Reservoirs
• Channel Straightening

Question 2

What are the social benefits of embankments?

Answer 2

• safer from flooding

* walking routes for locals and tourists

Question 3

What are the economic benefits of embankments?

Answer 3

Cheap compared to other methods.

Question 4

What are the environmental benefits of embankments?

Answer 4

Earthen embankments create habitats for riverbank animals.

Question 5

What are the social costs of embankments?

Answer 5

• Deprives people of easy access for fishing and boating

* Not as reliable as other methods so gives people a false sense of security, possibly leaving them unprepared

Question 6

What are the economic costs of embankments?

Answer 6

• Higher maintenance costs

* Earthen ones prone to erosion which will increase downstream sedimentation. This will incur a dredging cost.

Question 7

What are environmental costs of of embankments?

Answer 7

• If breached water stays on land for a long time as it has restricted access to the river
• Gabions and concrete displace animals
• Concrete may break causing mesh or concrete slabs to litter the river bank

Question 8

What are the social benefits of flood relief channels?

Answer 8

• Decreases flood risk
• New footpaths and cycle tracks
• Calm water is good for canoeing and boating
• Birdwatching and nature reserves can be set up

Question 9

What are the economic benefits of flood relief channels?

Answer 9

• Insurance costs are lower
• Values of houses increase
• More secure for setting up business ventures

Question 10

What are the environmental benefits of flood relief channels?

Answer 10

• Provides new habitat

* Tranquil setting when full of water

Question 11

What are the social costs of flood relief channels?

Answer 11

• People moved

* Downstream settlements have increased flood risk

Question 12

What are the economic costs of flood relief channels?

Answer 12

• Expensive
• Run out of funds
• Need maintenance and repair
• Take a long time to plan and build

Question 13

What are the environmental costs of flood relief channels?

Answer 13

• Habitats destroyed
• Variable water levels causes unreliable habitats
• look unattractive at times of low flow when concrete and gabions are exposed

Question 14

What are the social benefits of damns and reservoirs?

Answer 14

• source of drinking water
• provides hydroelectric power
• Highly effective against floods
• Boosts tourism

Question 15

What are the economic benefits of damns and reservoirs?

Answer 15

• boosts tourism
• provides hydroelectric power
• highly effective against floods

Question 16

What are the economic benefits of damns and reservoirs?

Answer 16

• Surrounding areas may be planted with forests
• promote new habitats
• provides hydroelectric power

Question 17

What are the social costs of damns and reservoirs?

Answer 17

• displaces people, especially farmers

Question 18

What are the economic costs of damns and reservoirs?

Answer 18

• Expensive
• money may be lost if there is a loss of industry and decreased demand for water
• soils downstream can become less fertile due to lack of sediment, decreasing crop yields

Question 19

What are the environmental costs of damns and reservoirs?

Answer 19

• Concrete interferes with migrating fish and their spawning grounds
• Algae collects behind the dam, deoxygenating the water
• Sudden water release could cause downstream bank erosion
• Could trigger an earthquake
• Landslides could occur at reservoirs

Question 20

What are the social benefits of channel straightening?

Answer 20

Reduces flood risk.

Question 21

What are the economic benefits of damns and reservoirs?

Answer 21

• Reduced length and straightened course can improve navigation, increasing trade at ports
• Home owners gain confidence in their property and have lower insurance rates.

Question 22

What are the social costs of channel straightening?

Answer 22

• when water meets a meandering section downstream the velocity is reduced. This causes sedimentation of the channel, increasing flood risk for other areas

Question 23

What are the economic costs of channel straightening?

Answer 23

• Expensive to straighten and dredge the river, which is necessary to prevent silt accumulation downstream

Question 24

What are the environmental costs of channel straightening?

Answer 24

• changes in hydrology and downstream flooding can endanger and destroy habitats as the river’s ecosystem has changed
• Visually unattractive
• Deprives animals from burrowing
• increased pollution on land from agrochemicals as runoff cannot easily drain into the river