Flocding

Question 1

What is flooding

Answer 1

When a water extends past its normal limits.e.g. When a river breaks its banks

Question 2

What two types of factors cause floods

Answer 2

Physical factors(natural)
Human Factors(man-made)

Question 3

What are flash floods

Answer 3

Floods that are so sudden we get no warning and people can get trapped and even drown.Bursts of heavy rainfall tend to cause then

Question 4

What can floods be caused by

Answer 4

Often heavy rainfall =causing water to run over the surface quickly and back to the river
Or melting snow and ice

Question 5

What does the river do once the channel is full

Answer 5

It bursts its banks

Question 6

Less infiltration =

Answer 6

More surface runoff

Question 7

More surface runoff=

Answer 7

Water reaches river more quickly

Question 8

What are some physical factors of a flood(refer to case study)

Answer 8

Heavy rain(200ml in 4hrs)
Impermeable rock(leads to more surface runoff)
Soggy soil(previous saturated soil)
Steep slopes(Drainage basin sloppy)
Tributaries
Flat flood plains(these flood naturally)
Strong coastal winds

Question 9

What human factors cause floods(refer to case study)

Answer 9

Built up areas more impermeable surfaces(in a town on a floodplain)
Deforestation,trees intercept rainfall and slow its movement down reducing flooding risks.Cutting down trees leads to more likely to flood(trees had been cut in the valley/bridges in town,100m Calvert)

Question 10

What were the effects of flooding

Answer 10

Tourism=tourists went home and season was cut short
Rivers=contamination by sewage
Property=over 50 cars washed out to sea
Businesses=many lost stock and were closed for 6-9months
Costs=repairs were estimated at over £500 million
Buildings=3 properties destroyed,80 damaged
Roads and car parks were damaged
Harbour area severely damaged

Question 11

Effects of flooding are

Answer 11

Long term and short term

Question 12

What do flood management schemes do

Answer 12

Aim to prevent flooding or reduce it to a poiny

Question 13

What is a flaw with flood schemes

Answer 13

They can have negative effects

Question 14

What are hard ways to reduce flooding

Answer 14

Build a dam
Widen river
Deepen river
Add embankments or levees
Straighten the river
Concrete banks

Question 15

What are soft ways to stop flooding

Answer 15

Plant trees
Controlled flooding

Question 16

What does a dam do

Answer 16

Advantages:
A dam traps the water and stores it in a reservoir.That water can then be released slowly in a controlled way.
Dams also generate electricity when water turns as it passes through the dam.This is called hydro-electric power
Disadvantages:
Dams are very expensive and land around it I’d flooded by the reservoir

Question 17

What does widening the river do

Answer 17

By digging out larger channel.however this means wildlife loses habitats as work is carried out

Question 18

How does deepening the river work

Answer 18

By digging out the channel.However this means wildlife loses habitats as work is carried out

Question 19

What does adding embankments or levees do

Answer 19

If you build the river banks it can hold more water,however they have to be maintained and if they break flooding can be worse

Question 20

How does straightening the river work

Answer 20

This speeds the flow of water to the sea up

Question 21

Concrete banks

Answer 21

Smoother than natural banks therefore water moves more quickly to the ses

Question 22

How does plating trees help

Answer 22

If you plant trees in a drainage basin they will intercept rain and absorb water reaching the river and slows down the movement of water to the river
However planting trees need land that is normally used for farming.Trees also take many years to reach maturity especially deciduous trees which intercept the most of water

Question 23

What does controlled flooding do

Answer 23

Allows designated areas to flood.This means excess water has somewhere to go as planners identify Whig areas of land to flood.This protects other areas downstream such as town and cities