4.8

Question 1

Soft engineering

Answer 1

Adapting to and using natural processes to stop damage

Question 2

Hard engineering

Answer 2

Defending against the environment to stop damage

Question 3

Flood walls

Answer 3

Building high walls or embankments alongside a river to increase its capacity
Advantages : Fairly cheap, low maintenance, useful in places where there is little space (eg town centres), used for other purposes like a walkway
Disadvantages: Disperses water quickly but can increase flood risk down stream, can be ugly

Question 4

Levees

Answer 4

Very similar to flood walls, built at a distance to increase river capacity
Advantages: allows people to live on flood plains, can be natural looking, increases river capacity, can be used as paths
Disadvantages: can be expensive, can increase flood risk downstream, can fail by over topping, slumping or erosion

Question 5

Dredging

Answer 5

Digging out the bottom of a channel to increase the capacity
Advantages:fairly cheap, speeds up flow, increases river capacity, can be combined with other methods
Disadvantages: not particularly effective, needs constant maintenance after every heavy rainfall

Question 6

Flood relief channelling

Answer 6

Lining river channels with concrete to increase capacity or creating extra river channels to divert water from high risk areas
Advantages: little maintenance, effective, speeds up flow
Disadvantages: expensive with high amounts of manual labour

Question 7

Flood plain retention

Answer 7

Lowering the level of the flood plain
Advantages: increased ability to store flood water
Disadvantages: £1.2 million per 2km stretch of river, means that the flood plain isn’t usable for building on

Question 8

River channel restoration

Answer 8

Rebuilding meanders, lowering banks, stripping away hard engineering, planting vegetation
Advantages: improved ecology ( roughly 30%), aesthetic look
Disadvantages: needs maintenance, £1.2 million per 2km stretch of river

Question 9

Demountable flood barriers

Answer 9

Temporary Barriers that are put up to block flood waters and increase river capacity in times of high water level
Advantages: Can be taken down so don’t spoil view, effective
Disadvantages: quite expensive, need warning time to be put up

Question 10

Flood gates

Answer 10

Huge gates or barriers near a river estuary that can be shut to stop flooding in surges
Advantages: protect huge areas of land, very effective
Disadvantages : very expensive , with high maintenance