Flood Management

Question 1

Define Hard Engineering

Answer 1

man - made structures that are usually large scale and have a large impact on the environment

Question 2

Define Soft Engineering

Answer 2

Involves adapting a river and sustainable solutions that work in harmony with the environment.

Question 3

Examples of Hard Engineering

Answer 3

Dams and Reservoirs, Channel straightening, Flood relief channel and Man-made levees

Question 4

Dams and Reservoirs

Answer 4

Dams (huge walls) are built across the river usually in the upper course. A reservoir is an artificial lake formed behind the dam.

Question 5

Define dam

Answer 5

They are huge walls built across rivers which restricts the flow of water . It controls and usually slows down the flow of water

Question 6

Define reservoirs

Answer 6

The artificial lake behind the dam.

Question 7

Benefits of Dams

Answer 7

. Reservoirs stores water and release it slowly reducing the risk of flooding
. Water in the reservoir can be used for drinking and can be used to generate hydroelectric power

Question 8

Disadvantages of Dams

Answer 8

. They are very expensive to build
. If they fails they can cause catastrophic failure
. Eroded material is deposited in the reservoir and not along the river’s natural course. This makes farmland downstream less fertile.
. Construction of Dams means heavy machinery used with can increase pollution. Habitats can also be destroyed.

Question 9

Define Channel Straightening

Answer 9

The river’s course is straightened, widened and deepened. This means less meanders and a more efficient course which improves navigation of the river water.

Question 10

Advantages of Channel straightening

Answer 10

Water can move out of the area more quickly as its does not travel as far as slowly due to less meanders. There is less friction with the banks and beds meaning less faster flow.

Question 11

Disadvantages of channel straightening

Answer 11

Flooding may occur later downstream of the straightened channel instead since water is being carried there faster. It can destroy habitats.

Question 12

Define Man -Made levees

Answer 12

They are man made embankments on both sides of the river

Question 13

Advantages of man - made levees

Answer 13

Embankments mean that the river channel can hold more river. They are also quite cheap.

Question 14

Disadvantages of man - made levees

Answer 14

If the levee breaks it can cause terrible flooding. Regular maintenance is also required.

Question 15

Define flood - relief channel

Answer 15

An artificially made channel that is designed as a backup of bypass channel if a river floods.

Question 16

Benefits of flood - relief channel

Answer 16

It provides area for boating and canoeing. Footpaths and cycle paths are made. Insurance gets lowered and new habitats can thrive in the new water.

Question 17

Disadvantages of flood - relief channel

Answer 17

People have heave to be moved and it is very expensive for construction. It needs to repaired and maintained and habitats can be disturbed.

Question 18

Issues with habitats (long term and short term)

Answer 18

. When building dams, relief channel and channel straightening, habitats may be destroyed in the short - term. However in the long term new species may thrive and make up for the lost of previous habitats.

Question 19

Examples of soft engineering

Answer 19

Flood warnings, preparation, Flood plain zoning or doing nothing

Question 20

Define flood warning

Answer 20

People gets warned about possible flooding through TV, radio , newspapers and the internet.

Question 21

Advantages of flood warning

Answer 21

The impact of flooding gets reduce. People have time to move possessions upstairs and put sandbags

Question 22

Disadvantages of flood warning

Answer 22

They do not stop of flood from occurring. People who are poorer may not have access to radio and television.

Question 23

Define flood plain zoning

Answer 23

Allowing only certain land uses on the floodplain reduces the risk of flooding to houses and more important buildings. For example houses and roads are built far away from the river, whilst fields and grazing pasture lands are built closer to the river.

Question 24

Advantages of flood plain zoning

Answer 24

Risk of flooding is reduced. Impermeable surfaces are not created such as roads. There is not many roads to damage

Question 25

Disadvantages of flood plain zoning

Answer 25

The flood will still causes damage to certain parts. The risk of flooding is not reduced. It is not always easy to change existing land uses.