RIVERS - management

Question 1

what are the hard engineering strategies?

Answer 1

• dams and reservoirs
• river straightening and dredging
• embankments
• flod relief channels

Question 2

what are dams and reservoirs?

Answer 2

○ Traps water, which builds up behind it forming a reservoir. Water can be released in a controlled way

Question 3

what is river straightening and dredging?

Answer 3

speeds up river so high volumes of water can pass through faster. Dredging deepens the river so it can hold more water.

Question 4

what are embankments?

Answer 4

Raising the bands of the river means that it can hold more water

Question 5

what are flood relief channels?

Answer 5

Empty channels that let water flow in and out. It is taken to an area where it can be absorbed or re-enters the river further down it’s course.

Question 6

what are the positives of dams and reservoirs?

Answer 6

• Can be used to produce electricity by passing the water through a turbine.
• Reservoirs can attract tourists

Question 7

what are the positives of river straightening and dredging?

Answer 7

• More water can be held in the channel

- Reduces flood risk in built up areas.

Question 8

what are the positives of embankments?

Answer 8

• Cheap one-off cost

- Allows for flood water to be contained within the river

Question 9

what are the positives of flood relief channels?

Answer 9

• Removes excess water from river channel so it reduces flooding

Question 10

negatives of dams and reservoirs?

Answer 10

• Expensive
• Dams trap sediment which means the reservoir holds less water.
• Habitats are flooded often leading to rotten veg. this releases greenhouse gasses
• Settlements are lost leading to the displacement of people

Question 11

negatives of River straightening and dredging?

Answer 11

• Dredging needs to be done frequently

- Speeding up the river increases flood risk downstream

Question 12

negatives of embankments?

Answer 12

• Looks unnatural

- Water speeds up and can increase flood risk downstream

Question 13

negatives of flood relief channels?

Answer 13

• Expensive to build

- If water level continues to rise the relief channel may also flood.

Question 14

what are the soft engineering techniques?

Answer 14

flood warnings and prep

floodplain zones

Question 15

what happens in flood warnings?

Answer 15

The environmental agency monitors rivers and flood areas and issues warnings to other sources.

Question 16

what is a floodplain zone?

Answer 16

Allowing only certain land uses on the floodplain reduces risk of flooding houses or important buildings

Question 17

negatives of flood plain zone/?

Answer 17

○ Not always possible to change existing land uses

○ Planners have to decide what types of flood to plan for

Question 18

negatives of flood warnings and prep?

Answer 18

• Some people may not be able to see flood warnings
• Flash floods may happen to quick for people to prepare so it becomes ineffective
• They don’t stop land from flooding

Question 19

positives of flood plain zones?

Answer 19

• More expensive buildings and land uses are further away from the river, so they have reduces flood risk
• Less damage

Question 20

positives of flood warnings and preparation?

Answer 20

• People have time to protect their properties

- Many possessions can be saved