River Management Strategies

Question 1

Name some hard engineering techniques

Answer 1

Dams and reservoirs, river straightening and dredging, embankments, flood relief channels

Question 2

Pros of dams and reservoirs

Answer 2

Can be used to produce electricity by passing water through a turbine and reservoirs can attract tourists

Question 3

Cons of dams and reservoirs

Answer 3

Very expensive, dams trap sediment meaning reservoirs can’t hold as much, habitats are flooded often leading to rotting vegetation then releasing methane and finally settlements are lost leading to displacement

Question 4

Pros of river straightening and dredging

Answer 4

More water can be held in the channel and can be used to reduce flood risk

Question 5

Cons of river straightening and dredging

Answer 5

Dredging needs to be done frequently and speeding up the river increases flood risk downstream

Question 6

Pros of embankments

Answer 6

Cheap and allows for flood water to be contained within the river

Question 7

Cons of embankments

Answer 7

Looks unnatural and water speeds up and can increase flood risk

Question 8

Pros of flood relief channels

Answer 8

Removes excess water from the river channel to reduce flooding

Question 9

Cons of flood relief channels

Answer 9

Expensive and if water levels continue to rise the relief channel may also flood

Question 10

What is the purpose of dams and reservoirs

Answer 10

Dams trap water which builds up behind it forming a reservoir

Question 11

What is the purpose of river straightening and dredging

Answer 11

Straightening the river speeds up the water so high volumes can pass through quickly and dredging makes the river deeper so it can hold more water

Question 12

What is the purpose of embankments

Answer 12

Raising the banks of a river means that it can hold more water

Question 13

What is the purpose of flood relief channels

Answer 13

Floodwater flows into the relief channel and is taken into an area where it can be absorbed or re-enters the river further down

Question 14

Name some soft engineering strategies for rivers

Answer 14

Flood warning and preparations, floodplain zoning

Question 15

Pros of flood warnings and preparations

Answer 15

People have time to protect their properties and many possessions can be saved resulting in fewer insurance claims

Question 16

Cons of warnings and preparations

Answer 16

Some people may not be able to access the warnings, flash floods may happen too quickly for a warning and they do not stop the land from flooding

Question 17

Pros of floodplain zoning

Answer 17

More than expensive buildings and land uses are further away from the river so have reduced flood risk and less damage is caused leading to fewer insurance claims

Question 18

Cons of floodplain zoning

Answer 18

Not always possible to change existing land uses and planners have to decide what type of flood to plan for